---------------------------------------------------------- Yak-List Digest Archive --- Total Messages Posted Tue 06/11/13: 16 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:58 AM - Re: Air system 'stuff' (A. Dennis Savarese) 2. 05:40 AM - CJ6 engine exhaust system collars (CJ6XXK) 3. 05:57 AM - Re: Air system 'stuff' (John Nolan) 4. 06:14 AM - Re: Air system 'stuff' (Bitterlich, Mark G CIV NAVAIR, WD) 5. 06:36 AM - Re: Air system 'stuff' (A. Dennis Savarese) 6. 06:51 AM - Re: Air system 'stuff' (A. Dennis Savarese) 7. 06:52 AM - Re: Air system 'stuff' (John Nolan) 8. 06:59 AM - Re: Air system 'stuff' (Bitterlich, Mark G CIV NAVAIR, WD) 9. 07:07 AM - Re: Air system 'stuff' (A. Dennis Savarese) 10. 07:22 AM - Re: Air system 'stuff' (Mark Davis) 11. 07:52 AM - Re: Air system 'stuff' (bill wade) 12. 08:28 AM - Re: Air system 'stuff' (A. Dennis Savarese) 13. 08:32 AM - Re: Air system 'stuff' (Bitterlich, Mark G CIV NAVAIR, WD) 14. 02:18 PM - Re: Air system 'stuff' (bill wade) 15. 02:32 PM - Re: Air system 'stuff' (A. Dennis Savarese) 16. 07:40 PM - Fw: Parker pop-off in use on my CJ (Roger Kemp M.D.) ________________________________ Message 1 _____________________________________ Time: 04:58:01 AM PST US From: "A. Dennis Savarese" Subject: Re: Yak-List: Air system 'stuff' Since neither the CJ nor the Yak 52, which have 100% identical gear and flap selectors for both front and rear cockpits, the rear cockpit gear and flap selectors are no longer used as was originally intended; as primary trainers. Therefore gear and flap selectors in the rear cockpit serve no functional benefit other than to pass the air pressure through them to the front cockpit. Why not fabricate a 3 valve and 5 valve bypass 'block' which could replace both of these "rarely ever used" components and eliminate potential failures in the pneumatic system? This is not difficult to do. In fact, I am pretty sure Jim Goolsby modified his rear gear selector and created a bypass. Thus he eliminated the potential failure of the unit. I personally fabricated a bypass configuration for one Yak 52 and completely removed the rear gear selector. Replacing a rear gear selector in a Yak 52 is far more difficult than on a CJ because the CJ's gear selector can be accessed from behind the front seat. In the Yak 52 you need a 10 year old skinny kid to get under the instrument panel. If you have never disassembled a rear gear selector after it has started leaking, you would not believe the rust and junk that accumulates inside this piece of equipment when it is never used. And many folks never even test them during the condition inspection. So they just sit there and corrode over time. My contention is, if it is not used and can and will cause pneumatic system problems, why not remove it from the system and eliminate the potential problem once and for all. Dennis A. Dennis Savarese 334-285-6263 334-546-8182 (mobile) www.yak-52.com Skype - Yakguy1 On 6/10/2013 4:41 PM, doug sapp wrote: > Mark, > It has been my experience that 75% or more of the failures of QSF2A > valves (3 port valves to you 52 types), and 12-5522-00 (5 port valve) > are caused not by moisture/rust but by grit and or pieces of rusted > springs. Years of rusty springs and poor maintenance has resulted in > the majority of the air systems out there being contaminated to some > degree. To combat the base problem we switched to all stainless steel > springs in most all of our valves quite some time ago. The secondary > problem of contaminated pneumatic problems is harder to solve as > flushing the system out is very difficult. We are experimenting with > the installation of a second stainless steel desiccant filter > installed just prior to the rear gear valve, if successful this should > vastly extend the life of these expensive valves. > > Best, > Doug > > On Mon, Jun 10, 2013 at 12:10 PM, Bitterlich, Mark G CIV NAVAIR, WD > > wrote: > > WD" > > > Thanks for the expert advice Doug. I had never even considered that. > > By the way, there is an air filter of sorts in the YAK-50. It is > located on the "T" air divider area where all the check valves are > located (four of them). It appears to be a circular device with > fittings at both ends and is possibly filled with something like steel > wool. In any case, whatever was in mine came all to pieces and junked > up the check valves. > > Again: Good advice on a better filter. Hmmm. > > Mark > > > -----Original Message----- > From: owner-yak-list-server@matronics.com > > [mailto:owner-yak-list-server@matronics.com > ] On Behalf Of doug sapp > Sent: Monday, June 10, 2013 14:44 > To: yak-list@matronics.com > Subject: Re: Yak-List: Air system 'stuff' > > Cory, > Mark is correct in all he said, however the valve which you have > selected would be somewhat prone to problems if your upstream air > system > is not 100% free of foreign material, such as old std steel rusted > spring parts, dirt, grease, etc. These valves are intended for use in > clean environments, not the somewhat dirtier systems of the CJ6. > Placing the valve just after a high quality filter would both extend > it's life and lower the probability of reoccurring maintenance issues > I'm sure. > > Best, > Doug > > > On Mon, Jun 10, 2013 at 11:12 AM, Bitterlich, Mark G CIV NAVAIR, WD > > wrote: > > > NAVAIR, > WD" > > > Cory, > > Sorry to disagree, but just in the details. The valves that > you referenced are indeed pop-off valves. They open to release or > by-pass pressure to keep at a maintained value, exactly as does the > pressure relief valve that is in there now. That said, they are > of much > better design and should work much better than the ones that are in > there now, if you get one rated for the pressure and flow for our > application. > > Taken from the company's web site: > > "Although this valve operates very similar to a relief valve > which is usually designed to release pressure quickly as soon as > the set > pressure is exceeded , this valve is designed to relieve pressure more > gradually with changes in flow resulting in fewer pressure spikes when > the valve opens and closes. This is a direct-acting valve with an > adjustable spring operating against a piston subjected to the inlet > pressure of the valve. Increasing the spring compression will increase > the system or line pressure to be maintained. Reducing the spring > compression will reduce the system or line pressure to be > maintained. " > > The summation: > > "An increase in system pressure beyond the set point will > cause > the main valve to open and relieve or bypass the excess pressure." > > This is EXACTLY how our present valves work, but these are > easier to get and maintain. > > Mark > > p.s. Probably a darn good replacement. > > > -----Original Message----- > From: owner-yak-list-server@matronics.com > > [mailto:owner-yak-list-server@matronics.com > ] On Behalf Of Cory Robin > Sent: Sunday, June 09, 2013 10:09 > To: yak-list@matronics.com > Subject: Re: Yak-List: Air system 'stuff' > > I found a source of a back pressure relief valve. Rather > than > it popping off and reducing the pressure, it maintains the pressure at > your pre-set value. > > I've ordered a couple to test them. > > > https://straval.com/catlist-back-pressure-regulators/back-pressure-regul > ator-piston-angle-valve-threaded-bps-05 > > > > ========== > rget="_blank">http://www.matronics.com/Navigator?Yak-List > ========== > http://forums.matronics.com > ========== > le, List Admin. > ="_blank">http://www.matronics.com/contribution > ========== > > > ========== > rget="_blank">http://www.matronics.com/Navigator?Yak-List > ========== > http://forums.matronics.com > ========== > le, List Admin. > ="_blank">http://www.matronics.com/contribution > ========== > > > * > > > * ________________________________ Message 2 _____________________________________ Time: 05:40:54 AM PST US Subject: Yak-List: CJ6 engine exhaust system collars From: "CJ6XXK" Hi I have about 11-12 new cnc machined exhaust collars for the exhaust.I all so have 9 stubs as well to suit. let me know if your interested and would like pictures. Thanks Read this topic online here: http://forums.matronics.com/viewtopic.php?p=402473#402473 ________________________________ Message 3 _____________________________________ Time: 05:57:09 AM PST US Subject: Re: Yak-List: Air system 'stuff' From: John Nolan When removing any components from the aft cockpit I would consider the possibility of pilot incapacitation in the forward cockpit with a person in the back. Regards, John Nolan On Tue, Jun 11, 2013 at 7:55 AM, A. Dennis Savarese < dsavarese0812@bellsouth.net> wrote: > dsavarese0812@bellsouth.net> > > Since neither the CJ nor the Yak 52, which have 100% identical gear and > flap selectors for both front and rear cockpits, the rear cockpit gear and > flap selectors are no longer used as was originally intended; as primary > trainers. Therefore gear and flap selectors in the rear cockpit serve no > functional benefit other than to pass the air pressure through them to the > front cockpit. Why not fabricate a 3 valve and 5 valve bypass 'block' > which could replace both of these "rarely ever used" components and > eliminate potential failures in the pneumatic system? > > This is not difficult to do. In fact, I am pretty sure Jim Goolsby > modified his rear gear selector and created a bypass. Thus he eliminated > the potential failure of the unit. I personally fabricated a bypass > configuration for one Yak 52 and completely removed the rear gear selector. > Replacing a rear gear selector in a Yak 52 is far more difficult than on a > CJ because the CJ's gear selector can be accessed from behind the front > seat. In the Yak 52 you need a 10 year old skinny kid to get under the > instrument panel. > > If you have never disassembled a rear gear selector after it has started > leaking, you would not believe the rust and junk that accumulates inside > this piece of equipment when it is never used. And many folks never even > test them during the condition inspection. So they just sit there and > corrode over time. > > My contention is, if it is not used and can and will cause pneumatic > system problems, why not remove it from the system and eliminate the > potential problem once and for all. > Dennis > > A. Dennis Savarese > 334-285-6263 > 334-546-8182 (mobile) > www.yak-52.com > Skype - Yakguy1 > > On 6/10/2013 4:41 PM, doug sapp wrote: > >> Mark, >> It has been my experience that 75% or more of the failures of QSF2A >> valves (3 port valves to you 52 types), and 12-5522-00 (5 port valve) are >> caused not by moisture/rust but by grit and or pieces of rusted springs. >> Years of rusty springs and poor maintenance has resulted in the majority >> of the air systems out there being contaminated to some degree. To combat >> the base problem we switched to all stainless steel springs in most all of >> our valves quite some time ago. The secondary problem of contaminated >> pneumatic problems is harder to solve as flushing the system out is very >> difficult. We are experimenting with the installation of a second >> stainless steel desiccant filter installed just prior to the rear gear >> valve, if successful this should vastly extend the life of these expensive >> valves. >> >> Best, >> Doug >> >> On Mon, Jun 10, 2013 at 12:10 PM, Bitterlich, Mark G CIV NAVAIR, WD < >> mark.bitterlich@navy.mil >> >> wrote: >> >> WD" >> >> >> >> Thanks for the expert advice Doug. I had never even considered that. >> >> By the way, there is an air filter of sorts in the YAK-50. It is >> located on the "T" air divider area where all the check valves are >> located (four of them). It appears to be a circular device with >> fittings at both ends and is possibly filled with something like steel >> wool. In any case, whatever was in mine came all to pieces and junked >> up the check valves. >> >> Again: Good advice on a better filter. Hmmm. >> >> Mark >> >> >> -----Original Message----- >> From: owner-yak-list-server@**matronics.com >> >> > >> [mailto:owner-yak-list-server@**matronics.com >> >] >> On Behalf Of doug sapp >> Sent: Monday, June 10, 2013 14:44 >> To: yak-list@matronics.com >> Subject: Re: Yak-List: Air system 'stuff' >> >> Cory, >> Mark is correct in all he said, however the valve which you have >> selected would be somewhat prone to problems if your upstream air >> system >> is not 100% free of foreign material, such as old std steel rusted >> spring parts, dirt, grease, etc. These valves are intended for use in >> clean environments, not the somewhat dirtier systems of the CJ6. >> Placing the valve just after a high quality filter would both extend >> it's life and lower the probability of reoccurring maintenance issues >> I'm sure. >> >> Best, >> Doug >> >> >> On Mon, Jun 10, 2013 at 11:12 AM, Bitterlich, Mark G CIV NAVAIR, WD >> >> >> wrote: >> >> >> NAVAIR, >> WD" >> >> >> >> Cory, >> >> Sorry to disagree, but just in the details. The valves that >> you referenced are indeed pop-off valves. They open to release or >> by-pass pressure to keep at a maintained value, exactly as does the >> pressure relief valve that is in there now. That said, they are >> of much >> better design and should work much better than the ones that are in >> there now, if you get one rated for the pressure and flow for our >> application. >> >> Taken from the company's web site: >> >> "Although this valve operates very similar to a relief valve >> which is usually designed to release pressure quickly as soon as >> the set >> pressure is exceeded , this valve is designed to relieve pressure more >> gradually with changes in flow resulting in fewer pressure spikes when >> the valve opens and closes. This is a direct-acting valve with an >> adjustable spring operating against a piston subjected to the inlet >> pressure of the valve. Increasing the spring compression will increase >> the system or line pressure to be maintained. Reducing the spring >> compression will reduce the system or line pressure to be >> maintained. " >> >> The summation: >> >> "An increase in system pressure beyond the set point will >> cause >> the main valve to open and relieve or bypass the excess pressure." >> >> This is EXACTLY how our present valves work, but these are >> easier to get and maintain. >> >> Mark >> >> p.s. Probably a darn good replacement. >> >> >> -----Original Message----- >> From: owner-yak-list-server@**matronics.com >> >> > >> [mailto:owner-yak-list-server@**matronics.com >> >] >> On Behalf Of Cory Robin >> Sent: Sunday, June 09, 2013 10:09 >> To: yak-list@matronics.com >> Subject: Re: Yak-List: Air system 'stuff' >> >> I found a source of a back pressure relief valve. Rather >> than >> it popping off and reducing the pressure, it maintains the pressure at >> your pre-set value. >> >> I've ordered a couple to test them. >> >> >> https://straval.com/catlist-**back-pressure-regulators/back-** >> pressure-regul >> ator-piston-angle-valve-**threaded-bps-05 >> > pressure-regul%0Aator-piston-**angle-valve-threaded-bps-05 >> > >> >> >> >> >> >> >> >> ========== >> rget="_blank">http://www.**matronics.com/Navigator?Yak-**List >> ========== >> http://forums.matronics.com >> ========== >> le, List Admin. >> ="_blank">http://www.**matronics.com/contribution >> ========== >> >> >> >> >> >> >> >> >> >> >> >> >> ========== >> rget="_blank">http://www.**matronics.com/Navigator?Yak-**List >> ========== >> http://forums.matronics.com >> ========== >> le, List Admin. >> ="_blank">http://www.**matronics.com/contribution >> ========== >> >> >> >> >> * >> >> >> * >> > > ________________________________ Message 4 _____________________________________ Time: 06:14:53 AM PST US Subject: RE: Yak-List: Air system 'stuff' From: "Bitterlich, Mark G CIV NAVAIR, WD" I have the same concerns when flying my YAK-50. :-) No seriously.... with a "person" in the back, or "you" in the back? For those performing aerobatic flight instruction in their YAK-52's where they have some less than qualified person in the front seat, keeping the rear seat selectors and indicators working makes sense. Of course that also then assumes the same folks are going to pay special attention to the known problems that accumulate due to this decision. Otherwise the less than qualified person is probably going to be in the rear seat anyway... and if the owner/pilot is incapacitated in the front seat the passenger can land it gear up. :-) Just thinking out loud... sorry. Mark -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of John Nolan Sent: Tuesday, June 11, 2013 8:55 Subject: Re: Yak-List: Air system 'stuff' When removing any components from the aft cockpit I would consider the possibility of pilot incapacitation in the forward cockpit with a person in the back. Regards, John Nolan On Tue, Jun 11, 2013 at 7:55 AM, A. Dennis Savarese wrote: Since neither the CJ nor the Yak 52, which have 100% identical gear and flap selectors for both front and rear cockpits, the rear cockpit gear and flap selectors are no longer used as was originally intended; as primary trainers. Therefore gear and flap selectors in the rear cockpit serve no functional benefit other than to pass the air pressure through them to the front cockpit. Why not fabricate a 3 valve and 5 valve bypass 'block' which could replace both of these "rarely ever used" components and eliminate potential failures in the pneumatic system? This is not difficult to do. In fact, I am pretty sure Jim Goolsby modified his rear gear selector and created a bypass. Thus he eliminated the potential failure of the unit. I personally fabricated a bypass configuration for one Yak 52 and completely removed the rear gear selector. Replacing a rear gear selector in a Yak 52 is far more difficult than on a CJ because the CJ's gear selector can be accessed from behind the front seat. In the Yak 52 you need a 10 year old skinny kid to get under the instrument panel. If you have never disassembled a rear gear selector after it has started leaking, you would not believe the rust and junk that accumulates inside this piece of equipment when it is never used. And many folks never even test them during the condition inspection. So they just sit there and corrode over time. My contention is, if it is not used and can and will cause pneumatic system problems, why not remove it from the system and eliminate the potential problem once and for all. Dennis A. Dennis Savarese 334-285-6263 334-546-8182 (mobile) www.yak-52.com Skype - Yakguy1 On 6/10/2013 4:41 PM, doug sapp wrote: Mark, It has been my experience that 75% or more of the failures of QSF2A valves (3 port valves to you 52 types), and 12-5522-00 (5 port valve) are caused not by moisture/rust but by grit and or pieces of rusted springs. Years of rusty springs and poor maintenance has resulted in the majority of the air systems out there being contaminated to some degree. To combat the base problem we switched to all stainless steel springs in most all of our valves quite some time ago. The secondary problem of contaminated pneumatic problems is harder to solve as flushing the system out is very difficult. We are experimenting with the installation of a second stainless steel desiccant filter installed just prior to the rear gear valve, if successful this should vastly extend the life of these expensive valves. Best, Doug On Mon, Jun 10, 2013 at 12:10 PM, Bitterlich, Mark G CIV NAVAIR, WD >> wrote: CIV NAVAIR, WD" >> Thanks for the expert advice Doug. I had never even considered that. By the way, there is an air filter of sorts in the YAK-50. It is located on the "T" air divider area where all the check valves are located (four of them). It appears to be a circular device with fittings at both ends and is possibly filled with something like steel wool. In any case, whatever was in mine came all to pieces and junked up the check valves. Again: Good advice on a better filter. Hmmm. Mark -----Original Message----- From: owner-yak-list-server@matronics.com > [mailto:owner-yak-list-server@matronics.com >] On Behalf Of doug sapp Sent: Monday, June 10, 2013 14:44 To: yak-list@matronics.com Subject: Re: Yak-List: Air system 'stuff' Cory, Mark is correct in all he said, however the valve which you have selected would be somewhat prone to problems if your upstream air system is not 100% free of foreign material, such as old std steel rusted spring parts, dirt, grease, etc. These valves are intended for use in clean environments, not the somewhat dirtier systems of the CJ6. Placing the valve just after a high quality filter would both extend it's life and lower the probability of reoccurring maintenance issues I'm sure. Best, Doug On Mon, Jun 10, 2013 at 11:12 AM, Bitterlich, Mark G CIV NAVAIR, WD >> wrote: Mark G CIV NAVAIR, WD" >> Cory, Sorry to disagree, but just in the details. The valves that you referenced are indeed pop-off valves. They open to release or by-pass pressure to keep at a maintained value, exactly as does the pressure relief valve that is in there now. That said, they are of much better design and should work much better than the ones that are in there now, if you get one rated for the pressure and flow for our application. Taken from the company's web site: "Although this valve operates very similar to a relief valve which is usually designed to release pressure quickly as soon as the set pressure is exceeded , this valve is designed to relieve pressure more gradually with changes in flow resulting in fewer pressure spikes when the valve opens and closes. This is a direct-acting valve with an adjustable spring operating against a piston subjected to the inlet pressure of the valve. Increasing the spring compression will increase the system or line pressure to be maintained. Reducing the spring compression will reduce the system or line pressure to be maintained. " The summation: "An increase in system pressure beyond the set point will cause the main valve to open and relieve or bypass the excess pressure." This is EXACTLY how our present valves work, but these are easier to get and maintain. Mark p.s. Probably a darn good replacement. -----Original Message----- From: owner-yak-list-server@matronics.com > [mailto:owner-yak-list-server@matronics.com >] On Behalf Of Cory Robin Sent: Sunday, June 09, 2013 10:09 To: yak-list@matronics.com Subject: Re: Yak-List: Air system 'stuff' I found a source of a back pressure relief valve. Rather than it popping off and reducing the pressure, it maintains the pressure at your pre-set value. I've ordered a couple to test them. https://straval.com/catlist-back-pressure-regulators/back-pressure-regul ator-piston-angle-valve-threaded-bps-05 > ========== rget="_blank">http://www.matronics.com/Navigator?Yak-List ========== http://forums.matronics.com ========== le, List Admin. ="_blank">http://www.matronics.com/contribution ========== ========== rget="_blank">http://www.matronics.com/Navigator?Yak-List ========== http://forums.matronics.com ========== le, List Admin. ="_blank">http://www.matronics.com/contribution ========== * * =================================== rget="_blank">http://www.matronics.com/Navigator?Yak-List =================================== http://forums.matronics.com =================================== le, List Admin. ="_blank">http://www.matronics.com/contribution =================================== ________________________________ Message 5 _____________________________________ Time: 06:36:38 AM PST US From: "A. Dennis Savarese" Subject: Re: Yak-List: Air system 'stuff' I am not suggesting this modification is for everyone. Each owner has to make his or her own decision whether to keep the gear and flap selectors in the rear cockpit or not. But if one decides to keep them, then by golly make sure you exercise them periodically. Not exercising them periodically can do more harm than good. We could create all kinds of scenarios John to justify keeping the no longer used components in the rear cockpit. Then what about the rear brake disabling capability? What about the instrument failure simulator switches? Next question would be, do you always fly with a qualified pilot in the rear seat? If you had a non-pilot in the rear seat (happens much more than with a qualified pilot) do you really think the non qualified person is going to know what to do in the first place? Lastly, the Yak 52 can be landed gear up. The question is, can the person in the back seat REALLY land the airplane? Gear up OR gear down? Dennis A. Dennis Savarese 334-285-6263 334-546-8182 (mobile) www.yak-52.com Skype - Yakguy1 On 6/11/2013 7:55 AM, John Nolan wrote: > When removing any components from the aft cockpit I would consider the > possibility of pilot incapacitation in the forward cockpit with a > person in the back. > > Regards, > > John Nolan > > > On Tue, Jun 11, 2013 at 7:55 AM, A. Dennis Savarese > > wrote: > > > > > Since neither the CJ nor the Yak 52, which have 100% identical > gear and flap selectors for both front and rear cockpits, the rear > cockpit gear and flap selectors are no longer used as was > originally intended; as primary trainers. Therefore gear and flap > selectors in the rear cockpit serve no functional benefit other > than to pass the air pressure through them to the front cockpit. > Why not fabricate a 3 valve and 5 valve bypass 'block' which could > replace both of these "rarely ever used" components and eliminate > potential failures in the pneumatic system? > > This is not difficult to do. In fact, I am pretty sure Jim > Goolsby modified his rear gear selector and created a bypass. Thus > he eliminated the potential failure of the unit. I personally > fabricated a bypass configuration for one Yak 52 and completely > removed the rear gear selector. Replacing a rear gear selector in > a Yak 52 is far more difficult than on a CJ because the CJ's gear > selector can be accessed from behind the front seat. In the Yak > 52 you need a 10 year old skinny kid to get under the instrument > panel. > > If you have never disassembled a rear gear selector after it has > started leaking, you would not believe the rust and junk that > accumulates inside this piece of equipment when it is never used. > And many folks never even test them during the condition > inspection. So they just sit there and corrode over time. > > My contention is, if it is not used and can and will cause > pneumatic system problems, why not remove it from the system and > eliminate the potential problem once and for all. > Dennis > > A. Dennis Savarese > 334-285-6263 > 334-546-8182 (mobile) > www.yak-52.com > Skype - Yakguy1 > > On 6/10/2013 4:41 PM, doug sapp wrote: > > Mark, > It has been my experience that 75% or more of the failures of > QSF2A valves (3 port valves to you 52 types), and 12-5522-00 > (5 port valve) are caused not by moisture/rust but by grit and > or pieces of rusted springs. Years of rusty springs and poor > maintenance has resulted in the majority of the air systems > out there being contaminated to some degree. To combat the > base problem we switched to all stainless steel springs in > most all of our valves quite some time ago. The secondary > problem of contaminated pneumatic problems is harder to solve > as flushing the system out is very difficult. We are > experimenting with the installation of a second stainless > steel desiccant filter installed just prior to the rear gear > valve, if successful this should vastly extend the life of > these expensive valves. > > Best, > Doug > > On Mon, Jun 10, 2013 at 12:10 PM, Bitterlich, Mark G CIV > NAVAIR, WD > >> wrote: > > NAVAIR, > WD" > >> > > Thanks for the expert advice Doug. I had never even > considered that. > > By the way, there is an air filter of sorts in the YAK-50. > It is > located on the "T" air divider area where all the check > valves are > located (four of them). It appears to be a circular > device with > fittings at both ends and is possibly filled with > something like steel > wool. In any case, whatever was in mine came all to > pieces and junked > up the check valves. > > Again: Good advice on a better filter. Hmmm. > > Mark > > > -----Original Message----- > From: owner-yak-list-server@matronics.com > > > > [mailto:owner-yak-list-server@matronics.com > > >] On Behalf Of > doug sapp > Sent: Monday, June 10, 2013 14:44 > To: yak-list@matronics.com > > > Subject: Re: Yak-List: Air system 'stuff' > > Cory, > Mark is correct in all he said, however the valve which > you have > selected would be somewhat prone to problems if your > upstream air > system > is not 100% free of foreign material, such as old std > steel rusted > spring parts, dirt, grease, etc. These valves are > intended for use in > clean environments, not the somewhat dirtier systems of > the CJ6. > Placing the valve just after a high quality filter would > both extend > it's life and lower the probability of reoccurring > maintenance issues > I'm sure. > > Best, > Doug > > > On Mon, Jun 10, 2013 at 11:12 AM, Bitterlich, Mark G CIV > NAVAIR, WD > > >> wrote: > > > G CIV > NAVAIR, > WD" > >> > > Cory, > > Sorry to disagree, but just in the details. The > valves that > you referenced are indeed pop-off valves. They open to > release or > by-pass pressure to keep at a maintained value, exactly as > does the > pressure relief valve that is in there now. That said, > they are > of much > better design and should work much better than the ones > that are in > there now, if you get one rated for the pressure and flow > for our > application. > > Taken from the company's web site: > > "Although this valve operates very similar to a > relief valve > which is usually designed to release pressure quickly as > soon as > the set > pressure is exceeded , this valve is designed to relieve > pressure more > gradually with changes in flow resulting in fewer pressure > spikes when > the valve opens and closes. This is a direct-acting valve > with an > adjustable spring operating against a piston subjected to > the inlet > pressure of the valve. Increasing the spring compression > will increase > the system or line pressure to be maintained. Reducing the > spring > compression will reduce the system or line pressure to be > maintained. " > > The summation: > > "An increase in system pressure beyond the set > point will > cause > the main valve to open and relieve or bypass the excess > pressure." > > This is EXACTLY how our present valves work, but > these are > easier to get and maintain. > > Mark > > p.s. Probably a darn good replacement. > > > -----Original Message----- > From: owner-yak-list-server@matronics.com > > > > [mailto:owner-yak-list-server@matronics.com > > >] On Behalf Of > Cory Robin > Sent: Sunday, June 09, 2013 10:09 > To: yak-list@matronics.com > > > Subject: Re: Yak-List: Air system 'stuff' > > I found a source of a back pressure relief valve. > Rather > than > it popping off and reducing the pressure, it maintains the > pressure at > your pre-set value. > > I've ordered a couple to test them. > > > https://straval.com/catlist-back-pressure-regulators/back-pressure-regul > ator-piston-angle-valve-threaded-bps-05 > > > > > ========== > > rget="_blank">http://www.matronics.com/Navigator?Yak-List > ========== > http://forums.matronics.com > ========== > le, List Admin. > ="_blank">http://www.matronics.com/contribution > ========== > > > ========== > rget="_blank">http://www.matronics.com/Navigator?Yak-List > ========== > http://forums.matronics.com > ========== > le, List Admin. > ="_blank">http://www.matronics.com/contribution > ========== > > > * > > > * > > > =================================== > rget="_blank">http://www.matronics.com/Navigator?Yak-List > =================================== > http://forums.matronics.com > =================================== > le, List Admin. > ="_blank">http://www.matronics.com/contribution > =================================== > > > * > > > * ________________________________ Message 6 _____________________________________ Time: 06:51:41 AM PST US From: "A. Dennis Savarese" Subject: Re: Yak-List: Air system 'stuff' Why in the world would you put a "less than qualified person" in the front seat of a Yak 52 in the first place? Putting anyone in the front seat of a Yak 52, including even a high time pilot, without proper aircraft-specific instruction and cockpit briefing BEFOREHAND is potentially an accident looking for a place to happen. Performing aerobatic flight instruction from the rear seat in a Yak 52 normally presumes the person in the front cockpit is a certificated pilot to begin with. If not, what is that person doing in the front seat in the first place? AND if an instructor is in the back seat and teaching aerobatics to certificated pilot, the instructor also has the responsibility to provide proper orientation and cockpit instruction long before ever having the person in the front seat push the start button. Dennis A. Dennis Savarese 334-285-6263 334-546-8182 (mobile) www.yak-52.com Skype - Yakguy1 On 6/11/2013 8:12 AM, Bitterlich, Mark G CIV NAVAIR, WD wrote: > > I have the same concerns when flying my YAK-50. :-) > > No seriously.... with a "person" in the back, or "you" in the back? For > those performing aerobatic flight instruction in their YAK-52's where > they have some less than qualified person in the front seat, keeping the > rear seat selectors and indicators working makes sense. Of course that > also then assumes the same folks are going to pay special attention to > the known problems that accumulate due to this decision. > > Otherwise the less than qualified person is probably going to be in the > rear seat anyway... and if the owner/pilot is incapacitated in the front > seat the passenger can land it gear up. :-) Just thinking out loud... > sorry. > > Mark > > > > -----Original Message----- > From: owner-yak-list-server@matronics.com > [mailto:owner-yak-list-server@matronics.com] On Behalf Of John Nolan > Sent: Tuesday, June 11, 2013 8:55 > To: yak-list@matronics.com > Subject: Re: Yak-List: Air system 'stuff' > > When removing any components from the aft cockpit I would consider the > possibility of pilot incapacitation in the forward cockpit with a person > in the back. > > Regards, > > John Nolan > > > > > > On Tue, Jun 11, 2013 at 7:55 AM, A. Dennis Savarese > wrote: > > > > > Since neither the CJ nor the Yak 52, which have 100% identical > gear and flap selectors for both front and rear cockpits, the rear > cockpit gear and flap selectors are no longer used as was originally > intended; as primary trainers. Therefore gear and flap selectors in the > rear cockpit serve no functional benefit other than to pass the air > pressure through them to the front cockpit. Why not fabricate a 3 > valve and 5 valve bypass 'block' which could replace both of these > "rarely ever used" components and eliminate potential failures in the > pneumatic system? > > This is not difficult to do. In fact, I am pretty sure Jim > Goolsby modified his rear gear selector and created a bypass. Thus he > eliminated the potential failure of the unit. I personally fabricated a > bypass configuration for one Yak 52 and completely removed the rear gear > selector. Replacing a rear gear selector in a Yak 52 is far more > difficult than on a CJ because the CJ's gear selector can be accessed > from behind the front seat. In the Yak 52 you need a 10 year old skinny > kid to get under the instrument panel. > > If you have never disassembled a rear gear selector after it has > started leaking, you would not believe the rust and junk that > accumulates inside this piece of equipment when it is never used. And > many folks never even test them during the condition inspection. So > they just sit there and corrode over time. > > My contention is, if it is not used and can and will cause > pneumatic system problems, why not remove it from the system and > eliminate the potential problem once and for all. > Dennis > > A. Dennis Savarese > 334-285-6263 > 334-546-8182 (mobile) > www.yak-52.com > Skype - Yakguy1 > > On 6/10/2013 4:41 PM, doug sapp wrote: > > > Mark, > It has been my experience that 75% or more of the > failures of QSF2A valves (3 port valves to you 52 types), and 12-5522-00 > (5 port valve) are caused not by moisture/rust but by grit and or pieces > of rusted springs. Years of rusty springs and poor maintenance has > resulted in the majority of the air systems out there being contaminated > to some degree. To combat the base problem we switched to all stainless > steel springs in most all of our valves quite some time ago. The > secondary problem of contaminated pneumatic problems is harder to solve > as flushing the system out is very difficult. We are experimenting with > the installation of a second stainless steel desiccant filter installed > just prior to the rear gear valve, if successful this should vastly > extend the life of these expensive valves. > > Best, > Doug > > On Mon, Jun 10, 2013 at 12:10 PM, Bitterlich, Mark G CIV > NAVAIR, WD >> wrote: > > CIV NAVAIR, > WD" >> > > Thanks for the expert advice Doug. I had never even > considered that. > > By the way, there is an air filter of sorts in the > YAK-50. It is > located on the "T" air divider area where all the > check valves are > located (four of them). It appears to be a circular > device with > fittings at both ends and is possibly filled with > something like steel > wool. In any case, whatever was in mine came all to > pieces and junked > up the check valves. > > Again: Good advice on a better filter. Hmmm. > > Mark > > > -----Original Message----- > From: owner-yak-list-server@matronics.com > > > > [mailto:owner-yak-list-server@matronics.com > > >] On Behalf Of doug sapp > Sent: Monday, June 10, 2013 14:44 > To: yak-list@matronics.com > > Subject: Re: Yak-List: Air system 'stuff' > > Cory, > Mark is correct in all he said, however the valve > which you have > selected would be somewhat prone to problems if your > upstream air > system > is not 100% free of foreign material, such as old > std steel rusted > spring parts, dirt, grease, etc. These valves are > intended for use in > clean environments, not the somewhat dirtier systems > of the CJ6. > Placing the valve just after a high quality filter > would both extend > it's life and lower the probability of reoccurring > maintenance issues > I'm sure. > > Best, > Doug > > > On Mon, Jun 10, 2013 at 11:12 AM, Bitterlich, Mark G > CIV NAVAIR, WD > >> > wrote: > > > Mark G CIV > NAVAIR, > WD" >> > > Cory, > > Sorry to disagree, but just in the details. > The valves that > you referenced are indeed pop-off valves. They open > to release or > by-pass pressure to keep at a maintained value, > exactly as does the > pressure relief valve that is in there now. That > said, they are > of much > better design and should work much better than the > ones that are in > there now, if you get one rated for the pressure and > flow for our > application. > > Taken from the company's web site: > > "Although this valve operates very similar > to a relief valve > which is usually designed to release pressure > quickly as soon as > the set > pressure is exceeded , this valve is designed to > relieve pressure more > gradually with changes in flow resulting in fewer > pressure spikes when > the valve opens and closes. This is a direct-acting > valve with an > adjustable spring operating against a piston > subjected to the inlet > pressure of the valve. Increasing the spring > compression will increase > the system or line pressure to be maintained. > Reducing the spring > compression will reduce the system or line pressure > to be > maintained. " > > The summation: > > "An increase in system pressure beyond the > set point will > cause > the main valve to open and relieve or bypass the > excess pressure." > > This is EXACTLY how our present valves work, > but these are > easier to get and maintain. > > Mark > > p.s. Probably a darn good replacement. > > > -----Original Message----- > From: owner-yak-list-server@matronics.com > > > > [mailto:owner-yak-list-server@matronics.com > > >] On Behalf Of Cory Robin > Sent: Sunday, June 09, 2013 10:09 > To: yak-list@matronics.com > > Subject: Re: Yak-List: Air system 'stuff' > > I found a source of a back pressure relief > valve. Rather > than > it popping off and reducing the pressure, it > maintains the pressure at > your pre-set value. > > I've ordered a couple to test them. > > > > https://straval.com/catlist-back-pressure-regulators/back-pressure-regul > l> > ator-piston-angle-valve-threaded-bps-05 > > l%0Aator-piston-angle-valve-threaded-bps-05 > l%0Aator-piston-angle-valve-threaded-bps-05> > > > > > > > > > ========== > > rget="_blank">http://www.matronics.com/Navigator?Yak-List > > ========== > http://forums.matronics.com > ========== > le, List Admin. > > ="_blank">http://www.matronics.com/contribution > > ========== > > > > > > > > > > > > > ========== > > rget="_blank">http://www.matronics.com/Navigator?Yak-List > > ========== > http://forums.matronics.com > ========== > le, List Admin. > ="_blank">http://www.matronics.com/contribution > > ========== > > > > > * > > > * > > > > =================================== > rget="_blank">http://www.matronics.com/Navigator?Yak-List > =================================== > http://forums.matronics.com > =================================== > le, List Admin. > ="_blank">http://www.matronics.com/contribution > =================================== > > > > > > ________________________________ Message 7 _____________________________________ Time: 06:52:50 AM PST US Subject: Re: Yak-List: Air system 'stuff' From: John Nolan Dennis, You are correct sir and I deffer to your superior knowledge of the 52. My post was, in general, for all to consider this possibility when disabling or keeping/enabling any system. Regards, John Nolan On Tue, Jun 11, 2013 at 9:34 AM, A. Dennis Savarese < dsavarese0812@bellsouth.net> wrote: > dsavarese0812@bellsouth.net> > > I am not suggesting this modification is for everyone. Each owner has to > make his or her own decision whether to keep the gear and flap selectors in > the rear cockpit or not. But if one decides to keep them, then by golly > make sure you exercise them periodically. Not exercising them periodically > can do more harm than good. > > We could create all kinds of scenarios John to justify keeping the no > longer used components in the rear cockpit. Then what about the rear brake > disabling capability? What about the instrument failure simulator > switches? Next question would be, do you always fly with a qualified pilot > in the rear seat? If you had a non-pilot in the rear seat (happens much > more than with a qualified pilot) do you really think the non qualified > person is going to know what to do in the first place? > > Lastly, the Yak 52 can be landed gear up. The question is, can the > person in the back seat REALLY land the airplane? Gear up OR gear down? > > Dennis > > A. Dennis Savarese > 334-285-6263 > 334-546-8182 (mobile) > www.yak-52.com > Skype - Yakguy1 > > On 6/11/2013 7:55 AM, John Nolan wrote: > >> When removing any components from the aft cockpit I would consider the >> possibility of pilot incapacitation in the forward cockpit with a person in >> the back. >> >> Regards, >> >> John Nolan >> >> >> >> On Tue, Jun 11, 2013 at 7:55 AM, A. Dennis Savarese < >> dsavarese0812@bellsouth.net >> >> wrote: >> >> >> >> >> >> Since neither the CJ nor the Yak 52, which have 100% identical >> gear and flap selectors for both front and rear cockpits, the rear >> cockpit gear and flap selectors are no longer used as was >> originally intended; as primary trainers. Therefore gear and flap >> selectors in the rear cockpit serve no functional benefit other >> than to pass the air pressure through them to the front cockpit. >> Why not fabricate a 3 valve and 5 valve bypass 'block' which could >> replace both of these "rarely ever used" components and eliminate >> potential failures in the pneumatic system? >> >> This is not difficult to do. In fact, I am pretty sure Jim >> Goolsby modified his rear gear selector and created a bypass. Thus >> he eliminated the potential failure of the unit. I personally >> fabricated a bypass configuration for one Yak 52 and completely >> removed the rear gear selector. Replacing a rear gear selector in >> a Yak 52 is far more difficult than on a CJ because the CJ's gear >> selector can be accessed from behind the front seat. In the Yak >> 52 you need a 10 year old skinny kid to get under the instrument >> panel. >> >> If you have never disassembled a rear gear selector after it has >> started leaking, you would not believe the rust and junk that >> accumulates inside this piece of equipment when it is never used. >> And many folks never even test them during the condition >> inspection. So they just sit there and corrode over time. >> >> My contention is, if it is not used and can and will cause >> pneumatic system problems, why not remove it from the system and >> eliminate the potential problem once and for all. >> Dennis >> >> A. Dennis Savarese >> 334-285-6263 >> 334-546-8182 (mobile) >> www.yak-52.com >> Skype - Yakguy1 >> >> On 6/10/2013 4:41 PM, doug sapp wrote: >> >> Mark, >> It has been my experience that 75% or more of the failures of >> QSF2A valves (3 port valves to you 52 types), and 12-5522-00 >> (5 port valve) are caused not by moisture/rust but by grit and >> or pieces of rusted springs. Years of rusty springs and poor >> maintenance has resulted in the majority of the air systems >> out there being contaminated to some degree. To combat the >> base problem we switched to all stainless steel springs in >> most all of our valves quite some time ago. The secondary >> problem of contaminated pneumatic problems is harder to solve >> as flushing the system out is very difficult. We are >> experimenting with the installation of a second stainless >> steel desiccant filter installed just prior to the rear gear >> valve, if successful this should vastly extend the life of >> these expensive valves. >> >> Best, >> Doug >> >> On Mon, Jun 10, 2013 at 12:10 PM, Bitterlich, Mark G CIV >> NAVAIR, WD > > >> >> >>> >> wrote: >> >> NAVAIR, >> WD" > > >> >> >>> >> >> Thanks for the expert advice Doug. I had never even >> considered that. >> >> By the way, there is an air filter of sorts in the YAK-50. >> It is >> located on the "T" air divider area where all the check >> valves are >> located (four of them). It appears to be a circular >> device with >> fittings at both ends and is possibly filled with >> something like steel >> wool. In any case, whatever was in mine came all to >> pieces and junked >> up the check valves. >> >> Again: Good advice on a better filter. Hmmm. >> >> Mark >> >> >> -----Original Message----- >> From: owner-yak-list-server@**matronics.com >> >> > >> >> >> >> >> [mailto:owner-yak-list-server@**matronics.com >> >> > >> >> >>] >> On Behalf Of >> doug sapp >> Sent: Monday, June 10, 2013 14:44 >> To: yak-list@matronics.com >> > >> Subject: Re: Yak-List: Air system 'stuff' >> >> Cory, >> Mark is correct in all he said, however the valve which >> you have >> selected would be somewhat prone to problems if your >> upstream air >> system >> is not 100% free of foreign material, such as old std >> steel rusted >> spring parts, dirt, grease, etc. These valves are >> intended for use in >> clean environments, not the somewhat dirtier systems of >> the CJ6. >> Placing the valve just after a high quality filter would >> both extend >> it's life and lower the probability of reoccurring >> maintenance issues >> I'm sure. >> >> Best, >> Doug >> >> >> On Mon, Jun 10, 2013 at 11:12 AM, Bitterlich, Mark G CIV >> NAVAIR, WD >> > > >> >> >>> >> wrote: >> >> >> G CIV >> NAVAIR, >> WD" > > >> >> >>> >> >> Cory, >> >> Sorry to disagree, but just in the details. The >> valves that >> you referenced are indeed pop-off valves. They open to >> release or >> by-pass pressure to keep at a maintained value, exactly as >> does the >> pressure relief valve that is in there now. That said, >> they are >> of much >> better design and should work much better than the ones >> that are in >> there now, if you get one rated for the pressure and flow >> for our >> application. >> >> Taken from the company's web site: >> >> "Although this valve operates very similar to a >> relief valve >> which is usually designed to release pressure quickly as >> soon as >> the set >> pressure is exceeded , this valve is designed to relieve >> pressure more >> gradually with changes in flow resulting in fewer pressure >> spikes when >> the valve opens and closes. This is a direct-acting valve >> with an >> adjustable spring operating against a piston subjected to >> the inlet >> pressure of the valve. Increasing the spring compression >> will increase >> the system or line pressure to be maintained. Reducing the >> spring >> compression will reduce the system or line pressure to be >> maintained. " >> >> The summation: >> >> "An increase in system pressure beyond the set >> point will >> cause >> the main valve to open and relieve or bypass the excess >> pressure." >> >> This is EXACTLY how our present valves work, but >> these are >> easier to get and maintain. >> >> Mark >> >> p.s. Probably a darn good replacement. >> >> >> -----Original Message----- >> From: owner-yak-list-server@**matronics.com >> >> > >> >> >> >> >> [mailto:owner-yak-list-server@**matronics.com >> >> > >> >> >>] >> On Behalf Of >> Cory Robin >> Sent: Sunday, June 09, 2013 10:09 >> To: yak-list@matronics.com >> > > >> Subject: Re: Yak-List: Air system 'stuff' >> >> I found a source of a back pressure relief valve. >> Rather >> than >> it popping off and reducing the pressure, it maintains the >> pressure at >> your pre-set value. >> >> I've ordered a couple to test them. >> >> >> https://straval.com/catlist-**back-pressure-regulators/back-** >> pressure-regul >> ator-piston-angle-valve-**threaded-bps-05 >> > back-pressure-regulators/back-**pressure-regul%0Aator-piston-** >> angle-valve-threaded-bps-05 >> > >> >> >> >> >> >> >> >> ========== >> rget="_blank">http://www.** >> matronics.com/Navigator?Yak-**List >> ========== >> http://forums.matronics.com >> ========== >> le, List Admin. >> ="_blank">http://www.**matronics.com/contribution >> ========== >> >> >> >> >> >> >> >> >> >> >> >> >> ========== >> rget="_blank">http://www.**matronics.com/Navigator?Yak-**List >> ========== >> http://forums.matronics.com >> ========== >> le, List Admin. >> ="_blank">http://www.**matronics.com/contribution >> ========== >> >> >> >> >> * >> >> >> * >> >> >> >> ==============================**===== >> rget="_blank">http://www.**matronics.com/Navigator?Yak-**List >> ==============================**===== >> http://forums.matronics.com >> ==============================**===== >> le, List Admin. >> ="_blank">http://www.**matronics.com/contribution >> ==============================**===== >> >> >> >> >> * >> >> >> * >> > > ________________________________ Message 8 _____________________________________ Time: 06:59:46 AM PST US Subject: RE: Yak-List: Air system 'stuff' From: "Bitterlich, Mark G CIV NAVAIR, WD" I totally agree. I was playing "Devils Advocate". Mark Bitterlich p.s. My Guy In Back is usually hanging on by a long rope. -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of A. Dennis Savarese Sent: Tuesday, June 11, 2013 9:50 Subject: Re: Yak-List: Air system 'stuff' --> Why in the world would you put a "less than qualified person" in the front seat of a Yak 52 in the first place? Putting anyone in the front seat of a Yak 52, including even a high time pilot, without proper aircraft-specific instruction and cockpit briefing BEFOREHAND is potentially an accident looking for a place to happen. Performing aerobatic flight instruction from the rear seat in a Yak 52 normally presumes the person in the front cockpit is a certificated pilot to begin with. If not, what is that person doing in the front seat in the first place? AND if an instructor is in the back seat and teaching aerobatics to certificated pilot, the instructor also has the responsibility to provide proper orientation and cockpit instruction long before ever having the person in the front seat push the start button. Dennis A. Dennis Savarese 334-285-6263 334-546-8182 (mobile) www.yak-52.com Skype - Yakguy1 On 6/11/2013 8:12 AM, Bitterlich, Mark G CIV NAVAIR, WD wrote: > --> > > I have the same concerns when flying my YAK-50. :-) > > No seriously.... with a "person" in the back, or "you" in the back? > For those performing aerobatic flight instruction in their YAK-52's > where they have some less than qualified person in the front seat, > keeping the rear seat selectors and indicators working makes sense. > Of course that also then assumes the same folks are going to pay > special attention to the known problems that accumulate due to this decision. > > Otherwise the less than qualified person is probably going to be in > the rear seat anyway... and if the owner/pilot is incapacitated in the > front seat the passenger can land it gear up. :-) Just thinking out loud... > sorry. > > Mark > > > > -----Original Message----- > From: owner-yak-list-server@matronics.com > [mailto:owner-yak-list-server@matronics.com] On Behalf Of John Nolan > Sent: Tuesday, June 11, 2013 8:55 > To: yak-list@matronics.com > Subject: Re: Yak-List: Air system 'stuff' > > When removing any components from the aft cockpit I would consider the > possibility of pilot incapacitation in the forward cockpit with a > person in the back. > > Regards, > > John Nolan > > > > > > On Tue, Jun 11, 2013 at 7:55 AM, A. Dennis Savarese > wrote: > > > > > Since neither the CJ nor the Yak 52, which have 100% identical gear > and flap selectors for both front and rear cockpits, the rear cockpit > gear and flap selectors are no longer used as was originally intended; > as primary trainers. Therefore gear and flap selectors in the rear > cockpit serve no functional benefit other than to pass the air > pressure through them to the front cockpit. Why not fabricate a 3 > valve and 5 valve bypass 'block' which could replace both of these > "rarely ever used" components and eliminate potential failures in the > pneumatic system? > > This is not difficult to do. In fact, I am pretty sure Jim Goolsby > modified his rear gear selector and created a bypass. Thus he > eliminated the potential failure of the unit. I personally fabricated > a bypass configuration for one Yak 52 and completely removed the rear > gear selector. Replacing a rear gear selector in a Yak 52 is far more > difficult than on a CJ because the CJ's gear selector can be accessed > from behind the front seat. In the Yak 52 you need a 10 year old > skinny kid to get under the instrument panel. > > If you have never disassembled a rear gear selector after it has > started leaking, you would not believe the rust and junk that > accumulates inside this piece of equipment when it is never used. And > many folks never even test them during the condition inspection. So > they just sit there and corrode over time. > > My contention is, if it is not used and can and will cause pneumatic > system problems, why not remove it from the system and eliminate the > potential problem once and for all. > Dennis > > A. Dennis Savarese > 334-285-6263 > 334-546-8182 (mobile) > www.yak-52.com > Skype - Yakguy1 > > On 6/10/2013 4:41 PM, doug sapp wrote: > > > Mark, > It has been my experience that 75% or more of the failures of QSF2A > valves (3 port valves to you 52 types), and 12-5522-00 > (5 port valve) are caused not by moisture/rust but by grit and or > pieces of rusted springs. Years of rusty springs and poor maintenance > has resulted in the majority of the air systems out there being > contaminated to some degree. To combat the base problem we switched > to all stainless steel springs in most all of our valves quite some > time ago. The secondary problem of contaminated pneumatic problems is > harder to solve as flushing the system out is very difficult. We are > experimenting with the installation of a second stainless steel > desiccant filter installed just prior to the rear gear valve, if > successful this should vastly extend the life of these expensive valves. > > Best, > Doug > > On Mon, Jun 10, 2013 at 12:10 PM, Bitterlich, Mark G CIV NAVAIR, WD > >> wrote: > CIV NAVAIR, > WD" >> > > Thanks for the expert advice Doug. I had never even considered > that. > > By the way, there is an air filter of sorts in the YAK-50. It > is > located on the "T" air divider area where all the check valves > are > located (four of them). It appears to be a circular device with > fittings at both ends and is possibly filled with something like > steel > wool. In any case, whatever was in mine came all to pieces and > junked > up the check valves. > > Again: Good advice on a better filter. Hmmm. > > Mark > > > -----Original Message----- > From: owner-yak-list-server@matronics.com > > > > [mailto:owner-yak-list-server@matronics.com > > >] On Behalf Of doug sapp > Sent: Monday, June 10, 2013 14:44 > To: yak-list@matronics.com > > Subject: Re: Yak-List: Air system 'stuff' > > Cory, > Mark is correct in all he said, however the valve which you have > selected would be somewhat prone to problems if your upstream > air > system > is not 100% free of foreign material, such as old std steel > rusted > spring parts, dirt, grease, etc. These valves are intended for > use in > clean environments, not the somewhat dirtier systems of the CJ6. > Placing the valve just after a high quality filter would both > extend > it's life and lower the probability of reoccurring maintenance > issues > I'm sure. > > Best, > Doug > > > On Mon, Jun 10, 2013 at 11:12 AM, Bitterlich, Mark G CIV NAVAIR, > WD > >> > wrote: > > Mark G CIV > NAVAIR, > WD" >> > > Cory, > > Sorry to disagree, but just in the details. > The valves that > you referenced are indeed pop-off valves. They open to release > or > by-pass pressure to keep at a maintained value, exactly as does > the > pressure relief valve that is in there now. That said, they are > of much > better design and should work much better than the ones that are > in > there now, if you get one rated for the pressure and flow for > our > application. > > Taken from the company's web site: > > "Although this valve operates very similar to a relief > valve > which is usually designed to release pressure quickly as soon as > the set > pressure is exceeded , this valve is designed to relieve > pressure more > gradually with changes in flow resulting in fewer pressure > spikes when > the valve opens and closes. This is a direct-acting valve with > an > adjustable spring operating against a piston subjected to the > inlet > pressure of the valve. Increasing the spring compression will > increase > the system or line pressure to be maintained. > Reducing the spring > compression will reduce the system or line pressure to be > maintained. " > > The summation: > > "An increase in system pressure beyond the set point > will > cause > the main valve to open and relieve or bypass the excess > pressure." > > This is EXACTLY how our present valves work, but these > are > easier to get and maintain. > > Mark > > p.s. Probably a darn good replacement. > > > -----Original Message----- > From: owner-yak-list-server@matronics.com > > > > [mailto:owner-yak-list-server@matronics.com > > >] On Behalf Of Cory Robin > Sent: Sunday, June 09, 2013 10:09 > To: yak-list@matronics.com > > Subject: Re: Yak-List: Air system 'stuff' > > I found a source of a back pressure relief > valve. Rather > than > it popping off and reducing the pressure, it maintains the > pressure at > your pre-set value. > > I've ordered a couple to test them. > > > > https://straval.com/catlist-back-pressure-regulators/back-pressure-reg > ul > gu > l> > ator-piston-angle-valve-threaded-bps-05 > > gu > l%0Aator-piston-angle-valve-threaded-bps-05 > gu l%0Aator-piston-angle-valve-threaded-bps-05> > > > > > > > > > ========== > > rget="_blank">http://www.matronics.com/Navigator?Yak-List > > ========== > http://forums.matronics.com > ========== > le, List Admin. > > ="_blank">http://www.matronics.com/contribution > > ========== > > > > > > > > > > > > > ========== > > rget="_blank">http://www.matronics.com/Navigator?Yak-List > > ========== > http://forums.matronics.com > ========== > le, List Admin. > ="_blank">http://www.matronics.com/contribution > > ========== > > > > > * > > > * > > > > =================================== > rget="_blank">http://www.matronics.com/Navigator?Yak-List > =================================== > http://forums.matronics.com > =================================== > le, List Admin. > ="_blank">http://www.matronics.com/contribution > =================================== > > > > > > ________________________________ Message 9 _____________________________________ Time: 07:07:12 AM PST US From: "A. Dennis Savarese" Subject: Re: Yak-List: Air system 'stuff' John, I would agree with you if the airplane's mission today was for primary or initial flight instruction. But since it is not, components that can potentially fail could be removed. Again, that decision is always up to the owner. Dennis A. Dennis Savarese 334-285-6263 334-546-8182 (mobile) www.yak-52.com Skype - Yakguy1 On 6/11/2013 8:50 AM, John Nolan wrote: > Dennis, > > You are correct sir and I deffer to your superior knowledge of the 52. > My post was, in general, for all to consider this possibility when > disabling or keeping/enabling any system. > > Regards, > > John Nolan > > > On Tue, Jun 11, 2013 at 9:34 AM, A. Dennis Savarese > > wrote: > > > > > I am not suggesting this modification is for everyone. Each owner > has to make his or her own decision whether to keep the gear and > flap selectors in the rear cockpit or not. But if one decides to > keep them, then by golly make sure you exercise them periodically. > Not exercising them periodically can do more harm than good. > > We could create all kinds of scenarios John to justify keeping the > no longer used components in the rear cockpit. Then what about > the rear brake disabling capability? What about the instrument > failure simulator switches? Next question would be, do you always > fly with a qualified pilot in the rear seat? If you had a > non-pilot in the rear seat (happens much more than with a > qualified pilot) do you really think the non qualified person is > going to know what to do in the first place? > > Lastly, the Yak 52 can be landed gear up. The question is, can > the person in the back seat REALLY land the airplane? Gear up OR > gear down? > > Dennis > > A. Dennis Savarese > 334-285-6263 > 334-546-8182 (mobile) > www.yak-52.com > Skype - Yakguy1 > > On 6/11/2013 7:55 AM, John Nolan wrote: > > When removing any components from the aft cockpit I would > consider the possibility of pilot incapacitation in the > forward cockpit with a person in the back. > > Regards, > > John Nolan > > > On Tue, Jun 11, 2013 at 7:55 AM, A. Dennis Savarese > > >> wrote: > > > >> > > Since neither the CJ nor the Yak 52, which have 100% identical > gear and flap selectors for both front and rear cockpits, > the rear > cockpit gear and flap selectors are no longer used as was > originally intended; as primary trainers. Therefore gear > and flap > selectors in the rear cockpit serve no functional benefit > other > than to pass the air pressure through them to the front > cockpit. Why not fabricate a 3 valve and 5 valve bypass > 'block' which could > replace both of these "rarely ever used" components and > eliminate > potential failures in the pneumatic system? > > This is not difficult to do. In fact, I am pretty sure Jim > Goolsby modified his rear gear selector and created a > bypass. Thus > he eliminated the potential failure of the unit. I personally > fabricated a bypass configuration for one Yak 52 and > completely > removed the rear gear selector. Replacing a rear gear > selector in > a Yak 52 is far more difficult than on a CJ because the > CJ's gear > selector can be accessed from behind the front seat. In > the Yak > 52 you need a 10 year old skinny kid to get under the > instrument > panel. > > If you have never disassembled a rear gear selector after > it has > started leaking, you would not believe the rust and junk that > accumulates inside this piece of equipment when it is > never used. > And many folks never even test them during the condition > inspection. So they just sit there and corrode over time. > > My contention is, if it is not used and can and will cause > pneumatic system problems, why not remove it from the > system and > eliminate the potential problem once and for all. > Dennis > > A. Dennis Savarese > 334-285-6263 > > 334-546-8182 > (mobile) > www.yak-52.com > Skype - Yakguy1 > > On 6/10/2013 4:41 PM, doug sapp wrote: > > Mark, > It has been my experience that 75% or more of the > failures of > QSF2A valves (3 port valves to you 52 types), and > 12-5522-00 > (5 port valve) are caused not by moisture/rust but by > grit and > or pieces of rusted springs. Years of rusty springs > and poor > maintenance has resulted in the majority of the air > systems > out there being contaminated to some degree. To > combat the > base problem we switched to all stainless steel springs in > most all of our valves quite some time ago. The secondary > problem of contaminated pneumatic problems is harder > to solve > as flushing the system out is very difficult. We are > experimenting with the installation of a second stainless > steel desiccant filter installed just prior to the > rear gear > valve, if successful this should vastly extend the life of > these expensive valves. > > Best, > Doug > > On Mon, Jun 10, 2013 at 12:10 PM, Bitterlich, Mark G CIV > NAVAIR, WD > > > > >>> wrote: > > G CIV > NAVAIR, > WD" > > > > >>> > > Thanks for the expert advice Doug. I had never even > considered that. > > By the way, there is an air filter of sorts in the > YAK-50. > It is > located on the "T" air divider area where all the > check > valves are > located (four of them). It appears to be a circular > device with > fittings at both ends and is possibly filled with > something like steel > wool. In any case, whatever was in mine came all to > pieces and junked > up the check valves. > > Again: Good advice on a better filter. Hmmm. > > Mark > > > -----Original Message----- > From: owner-yak-list-server@matronics.com > > > > > >> > [mailto:owner-yak-list-server@matronics.com > > > > > >>] On Behalf Of > doug sapp > Sent: Monday, June 10, 2013 14:44 > To: yak-list@matronics.com > > > >> > Subject: Re: Yak-List: Air system 'stuff' > > Cory, > Mark is correct in all he said, however the valve > which > you have > selected would be somewhat prone to problems if your > upstream air > system > is not 100% free of foreign material, such as old std > steel rusted > spring parts, dirt, grease, etc. These valves are > intended for use in > clean environments, not the somewhat dirtier > systems of > the CJ6. > Placing the valve just after a high quality filter > would > both extend > it's life and lower the probability of reoccurring > maintenance issues > I'm sure. > > Best, > Doug > > > On Mon, Jun 10, 2013 at 11:12 AM, Bitterlich, Mark > G CIV > NAVAIR, WD > > > > > >>> wrote: > > > "Bitterlich, Mark > G CIV > NAVAIR, > WD" > > > > >>> > > Cory, > > Sorry to disagree, but just in the > details. The > valves that > you referenced are indeed pop-off valves. They > open to > release or > by-pass pressure to keep at a maintained value, > exactly as > does the > pressure relief valve that is in there now. That > said, > they are > of much > better design and should work much better than the > ones > that are in > there now, if you get one rated for the pressure > and flow > for our > application. > > Taken from the company's web site: > > "Although this valve operates very similar > to a > relief valve > which is usually designed to release pressure > quickly as > soon as > the set > pressure is exceeded , this valve is designed to > relieve > pressure more > gradually with changes in flow resulting in fewer > pressure > spikes when > the valve opens and closes. This is a > direct-acting valve > with an > adjustable spring operating against a piston > subjected to > the inlet > pressure of the valve. Increasing the spring > compression > will increase > the system or line pressure to be maintained. > Reducing the > spring > compression will reduce the system or line > pressure to be > maintained. " > > The summation: > > "An increase in system pressure beyond the set > point will > cause > the main valve to open and relieve or bypass the > excess > pressure." > > This is EXACTLY how our present valves > work, but > these are > easier to get and maintain. > > Mark > > p.s. Probably a darn good replacement. > > > -----Original Message----- > From: owner-yak-list-server@matronics.com > > > > > >> > [mailto:owner-yak-list-server@matronics.com > > > > > >>] On Behalf Of > Cory Robin > Sent: Sunday, June 09, 2013 10:09 > To: yak-list@matronics.com > > > > > >> > Subject: Re: Yak-List: Air system 'stuff' > > I found a source of a back pressure relief > valve. > Rather > than > it popping off and reducing the pressure, it > maintains the > pressure at > your pre-set value. > > I've ordered a couple to test them. > > > https://straval.com/catlist-back-pressure-regulators/back-pressure-regul > ator-piston-angle-valve-threaded-bps-05 > > > > > ========== > > rget="_blank">http://www.matronics.com/Navigator?Yak-List > ========== > http://forums.matronics.com > ========== > le, List Admin. > > ="_blank">http://www.matronics.com/contribution > ========== > > > ========== > > rget="_blank">http://www.matronics.com/Navigator?Yak-List > ========== > http://forums.matronics.com > ========== > le, List Admin. > ="_blank">http://www.matronics.com/contribution > ========== > > > * > > > * > > > =================================== > rget="_blank">http://www.matronics.com/Navigator?Yak-List > =================================== > http://forums.matronics.com > =================================== > le, List Admin. > ="_blank">http://www.matronics.com/contribution > =================================== > > > * > > > * > > > =================================== > rget="_blank">http://www.matronics.com/Navigator?Yak-List > =================================== > http://forums.matronics.com > =================================== > le, List Admin. > ="_blank">http://www.matronics.com/contribution > =================================== > > > * > > > * ________________________________ Message 10 ____________________________________ Time: 07:22:55 AM PST US From: "Mark Davis" Subject: Re: Yak-List: Air system 'stuff' The good news with a YAK-52 is that if you kill the mags and land flaps up you likely will do very little damage to the aircraft in a gear up landing. This of course would depend on a GIB that understands this concept and actually gives a s#%t at the time! Mark Davis N44YK ----- Original Message ----- From: John Nolan To: yak-list@matronics.com Sent: Tuesday, June 11, 2013 6:55 AM Subject: Re: Yak-List: Air system 'stuff' When removing any components from the aft cockpit I would consider the possibility of pilot incapacitation in the forward cockpit with a person in the back. Regards, John Nolan On Tue, Jun 11, 2013 at 7:55 AM, A. Dennis Savarese wrote: Since neither the CJ nor the Yak 52, which have 100% identical gear and flap selectors for both front and rear cockpits, the rear cockpit gear and flap selectors are no longer used as was originally intended; as primary trainers. Therefore gear and flap selectors in the rear cockpit serve no functional benefit other than to pass the air pressure through them to the front cockpit. Why not fabricate a 3 valve and 5 valve bypass 'block' which could replace both of these "rarely ever used" components and eliminate potential failures in the pneumatic system? This is not difficult to do. In fact, I am pretty sure Jim Goolsby modified his rear gear selector and created a bypass. Thus he eliminated the potential failure of the unit. I personally fabricated a bypass configuration for one Yak 52 and completely removed the rear gear selector. Replacing a rear gear selector in a Yak 52 is far more difficult than on a CJ because the CJ's gear selector can be accessed from behind the front seat. In the Yak 52 you need a 10 year old skinny kid to get under the instrument panel. If you have never disassembled a rear gear selector after it has started leaking, you would not believe the rust and junk that accumulates inside this piece of equipment when it is never used. And many folks never even test them during the condition inspection. So they just sit there and corrode over time. My contention is, if it is not used and can and will cause pneumatic system problems, why not remove it from the system and eliminate the potential problem once and for all. Dennis A. Dennis Savarese 334-285-6263 334-546-8182 (mobile) www.yak-52.com Skype - Yakguy1 On 6/10/2013 4:41 PM, doug sapp wrote: Mark, It has been my experience that 75% or more of the failures of QSF2A valves (3 port valves to you 52 types), and 12-5522-00 (5 port valve) are caused not by moisture/rust but by grit and or pieces of rusted springs. Years of rusty springs and poor maintenance has resulted in the majority of the air systems out there being contaminated to some degree. To combat the base problem we switched to all stainless steel springs in most all of our valves quite some time ago. The secondary problem of contaminated pneumatic problems is harder to solve as flushing the system out is very difficult. We are experimenting with the installation of a second stainless steel desiccant filter installed just prior to the rear gear valve, if successful this should vastly extend the life of these expensive valves. Best, Doug On Mon, Jun 10, 2013 at 12:10 PM, Bitterlich, Mark G CIV NAVAIR, WD > wrote: NAVAIR, WD" > Thanks for the expert advice Doug. I had never even considered that. By the way, there is an air filter of sorts in the YAK-50. It is located on the "T" air divider area where all the check valves are located (four of them). It appears to be a circular device with fittings at both ends and is possibly filled with something like steel wool. In any case, whatever was in mine came all to pieces and junked up the check valves. Again: Good advice on a better filter. Hmmm. Mark -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com ] On Behalf Of doug sapp Sent: Monday, June 10, 2013 14:44 To: yak-list@matronics.com Subject: Re: Yak-List: Air system 'stuff' Cory, Mark is correct in all he said, however the valve which you have selected would be somewhat prone to problems if your upstream air system is not 100% free of foreign material, such as old std steel rusted spring parts, dirt, grease, etc. These valves are intended for use in clean environments, not the somewhat dirtier systems of the CJ6. Placing the valve just after a high quality filter would both extend it's life and lower the probability of reoccurring maintenance issues I'm sure. Best, Doug On Mon, Jun 10, 2013 at 11:12 AM, Bitterlich, Mark G CIV NAVAIR, WD > wrote: CIV NAVAIR, WD" > Cory, Sorry to disagree, but just in the details. The valves that you referenced are indeed pop-off valves. They open to release or by-pass pressure to keep at a maintained value, exactly as does the pressure relief valve that is in there now. That said, they are of much better design and should work much better than the ones that are in there now, if you get one rated for the pressure and flow for our application. Taken from the company's web site: "Although this valve operates very similar to a relief valve which is usually designed to release pressure quickly as soon as the set pressure is exceeded , this valve is designed to relieve pressure more gradually with changes in flow resulting in fewer pressure spikes when the valve opens and closes. This is a direct-acting valve with an adjustable spring operating against a piston subjected to the inlet pressure of the valve. Increasing the spring compression will increase the system or line pressure to be maintained. Reducing the spring compression will reduce the system or line pressure to be maintained. " The summation: "An increase in system pressure beyond the set point will cause the main valve to open and relieve or bypass the excess pressure." This is EXACTLY how our present valves work, but these are easier to get and maintain. Mark p.s. Probably a darn good replacement. -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com ] On Behalf Of Cory Robin Sent: Sunday, June 09, 2013 10:09 To: yak-list@matronics.com Subject: Re: Yak-List: Air system 'stuff' I found a source of a back pressure relief valve. Rather than it popping off and reducing the pressure, it maintains the pressure at your pre-set value. I've ordered a couple to test them. https://straval.com/catlist-back-pressure-regulators/back-pressure-regul ator-piston-angle-valve-threaded-bps-05 ========== rget="_blank">http://www.matronics.com/Navigator?Yak-List ========== http://forums.matronics.com ========== le, List Admin. ="_blank">http://www.matronics.com/contribution ========== ========== rget="_blank">http://www.matronics.com/Navigator?Yak-List ========== http://forums.matronics.com ========== le, List Admin. ="_blank">http://www.matronics.com/contribution ========== * * rget="_blank">http://www.matronics.com/Navigator?Yak-List http://forums.matronics.com le, List Admin. ="_blank">http://www.matronics.com/contribution ________________________________ Message 11 ____________________________________ Time: 07:52:48 AM PST US From: bill wade Subject: Re: Yak-List: Air system 'stuff' As were talking about air system stuff =0ADoes any one know if the air star t valve solenoid is polarity sensitive? The-wire plug connector can be at tached both ways.-Took it out cleaned it now it doesn't work I have-vol tage at the wire when start button is pushed, valve works when the lever is pushed down? Just ordered new Batteries.=0ABill Wade=0A =0A=0A____________ ____________________=0A From: Mark Davis =0ATo: yak-l ist@matronics.com =0ASent: Tuesday, June 11, 2013 10:20 AM=0ASubject: Re: Y ak-List: Air system 'stuff'=0A =0A=0A=0A =0AThe good news with a YAK-52 is that if you kill the =0Amags and land flaps up you likely will do very lit tle damage to the aircraft in =0Aa gear up landing.- This of course would depend on a GIB that understands =0Athis concept and actually gives a s#%t at the time! =0A- =0AMark Davis =0AN44YK =0A- =0A- =0A----- Original Message ----- =0A>From: John Nolan =0A>To: yak-list@matronics.com =0A>S ent: Tuesday, June 11, 2013 6:55 =0AAM =0A>Subject: Re: Yak-List: Air syste m 'stuff' =0A>=0A> =0A>When removing any components from the aft cockpit I would consider the possibility of pilot incapacitation in the forward coc kpit with a person in the back. =0A>=0A> =0A>Regards, =0A>=0A> =0A>John No lan=0A>=0A>=0A> =0A> =0A>=0A>=0A>=0A>On Tue, Jun 11, 2013 at 7:55 AM, A. De nnis Savarese wrote:=0A>=0A>--> Yak-List mess age posted by: "A. Dennis Savarese" =0A>>=0A> >Since neither the =0A CJ nor the Yak 52, which have 100% identical gear and flap selectors for =0A both front and rear cockpits, the rear cockp it gear and flap selectors are =0A no longer used as was originally inte nded; as primary trainers. Therefore =0A gear and flap selectors in the rear cockpit serve no functional benefit =0A other than to pass the air pressure through them to the front cockpit. =0A - Why not fabricate a 3 valve and 5 valve bypass 'block' which could =0A replace both of these "rarely ever used" components and eliminate potential =0A failures in t he pneumatic system?=0A>>=0A>>This is not difficult to do. =0A -In fac t, I am pretty sure Jim Goolsby modified his rear gear selector =0A and created a bypass. Thus he eliminated the potential failure of the unit. =0A -I personally fabricated a bypass configuration for one Yak 52 and =0A completely removed the rear gear selector. -Replacing a rear gear =0A selector in a Yak 52 is far more difficult than on a CJ because the CJ's =0A gear selector can be accessed from behind the front seat. -In the Yak =0A 52 you need a 10 year old skinny kid to get under the instr ument =0A panel.=0A>>=0A>>If you have never disassembled a rear gear sel ector after it =0A has started leaking, you would not believe the rust a nd junk that =0A accumulates inside this piece of equipment when it is n ever used. And many =0A folks never even test them during the condition inspection. -So they =0A just sit there and corrode over time.=0A>>=0A >>My contention is, if it is not =0A used and can and will cause pneumat ic system problems, why not remove it =0A from the system and eliminate the potential problem once and for =0A all.=0A>>Dennis=0A>>=0A>>A. Denni s Savarese=0A>>334-285-6263=0A>>334-546-8182-(mobile)=0A>>http://www.yak- 52.com/=0A>>Skype - =0A Yakguy1=0A>>=0A>>On 6/10/2013 4:41 PM, doug sapp wrote:=0A>>=0A>>Mark,=0A>>>It has been my experience that 75% or more of =0A the failures of QSF2A valves (3 port valves to you 52 types), and =0A 12-5522-00 (5 port valve) are caused not by moisture/rust but by g rit and =0A or pieces of rusted springs. -Years of rusty springs and poor =0A maintenance has resulted in the majority of the air systems out there =0A being contaminated to some degree. -To combat the base problem we =0A switched to all stainless steel springs in most all of our valves quite =0A some time ago. -The secondary problem of conta minated pneumatic =0A problems is harder to solve as flushing the syst em out is very difficult. =0A -We are experimenting with the install ation of a second stainless =0A steel desiccant filter installed just prior to the rear gear valve, if =0A successful this should vastly ext end the life of these expensive =0A valves.=0A>>>=0A>>>Best,=0A>>>Doug =0A>>>=0A>>>On Mon, Jun 10, 2013 at 12:10 PM, =0A Bitterlich, Mark G C IV NAVAIR, WD > lich, Mark G CIV NAVAIR,=0A>>>- - WD" >=0A>>>=0A>>>- =0A - Thanks for the expe rt advice Doug. -I had never even =0A considered that.=0A>>>=0A>>> - - By the way, there is an air filter =0A of sorts in the YAK-50. -It is=0A>>>- - located on the "T" =0A air divider area where a ll the check valves are=0A>>>- - located =0A (four of them). -It appears to be a circular device with=0A>>>- =0A - fittings at bot h ends and is possibly filled with something like =0A steel=0A>>>- - wool. -In any case, whatever was in mine came =0A all to pieces and junked=0A>>>- - up the check =0A valves.=0A>>>=0A>>>- - Ag ain: Good advice on a better filter. =0A -Hmmm.=0A>>>=0A>>>- - M ark=0A>>>=0A>>>=0A>>>- - =0A -----Original Message-----=0A>>>- - From: owner-yak-list-server@matronics.com=0A>>>- =0A - =0A>>>- =0A - [mailto:owner-y ak-list-server@matronics.com=0A>>>- =0A - ] On Behalf Of doug sapp=0A>>>- - Sent: Monday, Ju ne 10, 2013 =0A 14:44=0A>>>- - To: yak-list@matronics.com =0A>>>- - =0A Subject: Re: Yak-List: Air sy stem 'stuff'=0A>>>=0A>>>- - =0A Cory,=0A>>>- - Mark is correct in all he said, however the valve =0A which you have=0A>>>- - sel ected would be somewhat prone to =0A problems if your upstream air=0A> >>- - system=0A>>>- - is =0A not 100% free of foreign material , such as old std steel rusted=0A>>>- =0A - spring parts, dirt, gr ease, etc. -These valves are intended =0A for use in=0A>>>- - cl ean environments, not the somewhat dirtier =0A systems of the CJ6.=0A> >>- - Placing the valve just after a high =0A quality filter would both extend=0A>>>- - it's life and lower the =0A probability of r eoccurring maintenance issues=0A>>>- - I'm =0A sure.=0A>>>=0A>>> - - Best,=0A>>>- - Doug=0A>>>=0A>>>=0A>>>- =0A - On Mon, J un 10, 2013 at 11:12 AM, Bitterlich, Mark G CIV NAVAIR, =0A WD=0A>>> - - > wrote :=0A>>>=0A>>>=0A>>>- - - - - - --> =0A Yak-List message po sted by: "Bitterlich, Mark G CIV=0A>>>- - =0A NAVAIR,=0A>>>- - WD" >=0A>>>=0A> >>- =0A - - - - - Cory,=0A>>>=0A>>>- - - =0A - - - Sorry to disagree, but just in the details. The =0A valves that=0A>>>- - you referenced are indeed pop-off valves. =0A -Th ey open to release or=0A>>>- - by-pass pressure to keep at =0A a m aintained value, exactly as does the=0A>>>- - pressure relief =0A valve that is in there now. -That said, they are=0A>>>- - of =0A much=0A>>>- - better design and should work much better than the =0A ones that are in=0A>>>- - there now, if you get one rated for the =0A pressure and flow for our=0A>>>- - application.=0A>>>=0A>>>- =0A - - - - - Taken from the company's web =0A site: =0A>>>=0A>>>- - - - - - "Although this =0A valve operates very similar to a relief valve=0A>>>- - which is =0A usually desig ned to release pressure quickly as soon as=0A>>>- - =0A the set=0A >>>- - pressure is exceeded , this valve is designed to =0A reliev e pressure more=0A>>>- - gradually with changes in flow =0A result ing in fewer pressure spikes when=0A>>>- - the valve opens =0A and closes. This is a direct-acting valve with an=0A>>>- - =0A adjust able spring operating against a piston subjected to the =0A inlet=0A>> >- - pressure of the valve. Increasing the spring =0A compression will increase=0A>>>- - the system or line pressure to =0A be maint ained. Reducing the spring=0A>>>- - compression will =0A reduce th e system or line pressure to be=0A>>>- - maintained. =0A "=0A>>> =0A>>>- - - - - - The =0A summation:=0A>>>=0A>>>- - - - - - "An increase =0A in system pressure beyond the set poi nt will=0A>>>- - =0A cause=0A>>>- - the main valve to open and relieve or bypass the =0A excess pressure."=0A>>>=0A>>>- - - - - - This is =0A EXACTLY how our present valves work, but these are=0A>>>- - easier =0A to get and maintain.=0A>>>=0A>>>- - - - - - =0A Mark=0A>>>=0A>>>- - - - - - p.s. -Pr obably =0A a darn good replacement.=0A>>>=0A>>>=0A>>>- - - - - =0A - -----Original Message-----=0A>>>- - - - - =0A - From: owner-yak-list-server@matronics.com=0A>>>- =0A - =0A>>>- =0A - [mailto:owne r-yak-list-server@matronics.com=0A>>>- =0A - ] On Behalf Of Cory Robin=0A>>>- - - - - - Sent: =0A Sunday, June 09, 2013 10:09=0A>>>- - - - - - =0A To: yak-list@matronics.com =0A>>> - - =0A - - - - Subject: Re: Yak-List: Air system =0A 'stuff'=0A>>>=0A>>>- - - - - - I found a source =0A of a back pressure relief valve. - Rather=0A>>>- - =0A than=0A>>>- - it popping off and reducing the pressure, it =0A maintains the pre ssure at=0A>>>- - your pre-set =0A value.=0A>>>=0A>>>- - - - - - I've ordered a =0A couple to test them.=0A>>>=0A>>>=0A>>> - - https://straval.com/catlist-back-pressure-regulators/back-pressure- regul=0A>>>- =0A - ator-piston-angle-valve-threaded-bps-05=0A>>> - - =0A =0A>>>=0A>>>=0A>> >=0A>>>=0A>>>=0A>>>=0A>>>=0A>>>- =0A - - - - - === =========0A>>>- - - =0A - - - rget="_bla nk">http://www.matronics.com/Navigator?Yak-List=0A>>>- =0A - - - - - ============0A>>>- - http://forums.ma tronics.com/=0A>>>- - - =0A - - - ======== ====0A>>>- - - - - =0A - le, List Admin.=0A>>>- - - - - - =0A ="_blank">http://www.matronics.com/contribut ion=0A>>>- =0A - - - - - =0A ======== ====0A>>>=0A>>>=0A>>>=0A>>>=0A>>>=0A>>>=0A>>>=0A>>>=0A>>>=0A>>>=0A>>> =0A>>>=0A>>>- =0A - ============0A>>>- - rget="_blank">http://www.matronics.com/Navigator?Yak-List=0A>>>- =0A - ============0A>>>- - http://forums.matron ics.com/=0A>>>- - =0A ============0A>>>- - le, List Admin.=0A>>>- - =0A ="_blank">http://www.matronics. com/contribution=0A>>>- =0A - =0A ========= ===0A>>>=0A>>>=0A>>>=0A>>>=0A>>>*=0A>>>=0A>>>=0A>>>*=0A>>>=0A>>=0A>>= ===========0A>>rget="_blank">http://www.matronics.com /Navigator?Yak-List=0A>>================= ====================0A>>http://forums .matronics.com=0A>>================== ===================0A>>le, =0A List =0A Admin.=0A>>="_blank">http://www.matronics.com/contribution=0A>>= ===========0A>>=0A>>=0A>>=0A>>=0A>=0A>href="http://ww w.matronics.com/Navigator?Yak-List">http://www.matronics.com/Navigator?Yak- List=0Ahref="http://forums.matronics.com">http://forums.matronics.com=0Ah ref="http://www.matronics.com/contribution">http://www.matronics.com/c ============= ________________________________ Message 12 ____________________________________ Time: 08:28:13 AM PST US From: "A. Dennis Savarese" Subject: Re: Yak-List: Air system 'stuff' Bill, If I am not mistaken, a Cannon plug without a key-way indicates it can be connected either way. Since it is nothing more than a solenoid with power and ground being applied, it should work either way. You can easily test it though with a 24 volt battery and some leads. Connect them both ways and see if the solenoid engages or not. Battery voltage has a significant effect on whether the solenoid engages or not. Less than about 22 volts on the battery voltage instrument may not engage the solenoid. Dennis A. Dennis Savarese 334-285-6263 334-546-8182 (mobile) www.yak-52.com Skype - Yakguy1 On 6/11/2013 9:50 AM, bill wade wrote: > As were talking about air system stuff > Does any one know if the air start valve solenoid is polarity > sensitive? The wire plug connector can be attached both ways. Took it > out cleaned it now it doesn't work I have voltage at the wire when > start button is pushed, valve works when the lever is pushed down? > Just ordered new Batteries. > Bill Wade > > *From:* Mark Davis > *To:* yak-list@matronics.com > *Sent:* Tuesday, June 11, 2013 10:20 AM > *Subject:* Re: Yak-List: Air system 'stuff' > > The good news with a YAK-52 is that if you kill the mags and land > flaps up you likely will do very little damage to the aircraft in a > gear up landing. This of course would depend on a GIB that > understands this concept and actually gives a s#%t at the time! > Mark Davis > N44YK > > ----- Original Message ----- > *From:* John Nolan > *To:* yak-list@matronics.com > *Sent:* Tuesday, June 11, 2013 6:55 AM > *Subject:* Re: Yak-List: Air system 'stuff' > > When removing any components from the aft cockpit I would consider > the possibility of pilot incapacitation in the forward cockpit > with a person in the back. > > Regards, > > John Nolan > > > On Tue, Jun 11, 2013 at 7:55 AM, A. Dennis Savarese > > > wrote: > > > > > Since neither the CJ nor the Yak 52, which have 100% identical > gear and flap selectors for both front and rear cockpits, the > rear cockpit gear and flap selectors are no longer used as was > originally intended; as primary trainers. Therefore gear and > flap selectors in the rear cockpit serve no functional benefit > other than to pass the air pressure through them to the front > cockpit. Why not fabricate a 3 valve and 5 valve bypass > 'block' which could replace both of these "rarely ever used" > components and eliminate potential failures in the pneumatic > system? > > This is not difficult to do. In fact, I am pretty sure Jim > Goolsby modified his rear gear selector and created a bypass. > Thus he eliminated the potential failure of the unit. I > personally fabricated a bypass configuration for one Yak 52 > and completely removed the rear gear selector. Replacing a > rear gear selector in a Yak 52 is far more difficult than on a > CJ because the CJ's gear selector can be accessed from behind > the front seat. In the Yak 52 you need a 10 year old skinny > kid to get under the instrument panel. > > If you have never disassembled a rear gear selector after it > has started leaking, you would not believe the rust and junk > that accumulates inside this piece of equipment when it is > never used. And many folks never even test them during the > condition inspection. So they just sit there and corrode over > time. > > My contention is, if it is not used and can and will cause > pneumatic system problems, why not remove it from the system > and eliminate the potential problem once and for all. > Dennis > > A. Dennis Savarese > 334-285-6263 > 334-546-8182 (mobile) > http://www.yak-52.com/ > Skype - Yakguy1 > > On 6/10/2013 4:41 PM, doug sapp wrote: > > Mark, > It has been my experience that 75% or more of the failures > of QSF2A valves (3 port valves to you 52 types), and > 12-5522-00 (5 port valve) are caused not by moisture/rust > but by grit and or pieces of rusted springs. Years of > rusty springs and poor maintenance has resulted in the > majority of the air systems out there being contaminated > to some degree. To combat the base problem we switched to > all stainless steel springs in most all of our valves > quite some time ago. The secondary problem of > contaminated pneumatic problems is harder to solve as > flushing the system out is very difficult. We are > experimenting with the installation of a second stainless > steel desiccant filter installed just prior to the rear > gear valve, if successful this should vastly extend the > life of these expensive valves. > > Best, > Doug > > On Mon, Jun 10, 2013 at 12:10 PM, Bitterlich, Mark G CIV > NAVAIR, WD > >> wrote: > > CIV NAVAIR, > WD" > >> > > Thanks for the expert advice Doug. I had never even > considered that. > > By the way, there is an air filter of sorts in the > YAK-50. It is > located on the "T" air divider area where all the > check valves are > located (four of them). It appears to be a circular > device with > fittings at both ends and is possibly filled with > something like steel > wool. In any case, whatever was in mine came all to > pieces and junked > up the check valves. > > Again: Good advice on a better filter. Hmmm. > > Mark > > > -----Original Message----- > From: owner-yak-list-server@matronics.com > > > > [mailto:owner-yak-list-server@matronics.com > > >] On Behalf > Of doug sapp > Sent: Monday, June 10, 2013 14:44 > To: yak-list@matronics.com > > > > Subject: Re: Yak-List: Air system 'stuff' > > Cory, > Mark is correct in all he said, however the valve > which you have > selected would be somewhat prone to problems if your > upstream air > system > is not 100% free of foreign material, such as old std > steel rusted > spring parts, dirt, grease, etc. These valves are > intended for use in > clean environments, not the somewhat dirtier systems > of the CJ6. > Placing the valve just after a high quality filter > would both extend > it's life and lower the probability of reoccurring > maintenance issues > I'm sure. > > Best, > Doug > > > On Mon, Jun 10, 2013 at 11:12 AM, Bitterlich, Mark G > CIV NAVAIR, WD > > >> wrote: > > > Mark G CIV > NAVAIR, > WD" > >> > > Cory, > > Sorry to disagree, but just in the details. > The valves that > you referenced are indeed pop-off valves. They open > to release or > by-pass pressure to keep at a maintained value, > exactly as does the > pressure relief valve that is in there now. That > said, they are > of much > better design and should work much better than the > ones that are in > there now, if you get one rated for the pressure and > flow for our > application. > > Taken from the company's web site: > > "Although this valve operates very similar to > a relief valve > which is usually designed to release pressure quickly > as soon as > the set > pressure is exceeded , this valve is designed to > relieve pressure more > gradually with changes in flow resulting in fewer > pressure spikes when > the valve opens and closes. This is a direct-acting > valve with an > adjustable spring operating against a piston subjected > to the inlet > pressure of the valve. Increasing the spring > compression will increase > the system or line pressure to be maintained. Reducing > the spring > compression will reduce the system or line pressure to be > maintained. " > > The summation: > > "An increase in system pressure beyond the set > point will > cause > the main valve to open and relieve or bypass the > excess pressure." > > This is EXACTLY how our present valves work, > but these are > easier to get and maintain. > > Mark > > p.s. Probably a darn good replacement. > > > -----Original Message----- > From: owner-yak-list-server@matronics.com > > > > [mailto:owner-yak-list-server@matronics.com > > >] On Behalf > Of Cory Robin > Sent: Sunday, June 09, 2013 10:09 > To: yak-list@matronics.com > > > > Subject: Re: Yak-List: Air system 'stuff' > > I found a source of a back pressure relief > valve. Rather > than > it popping off and reducing the pressure, it maintains > the pressure at > your pre-set value. > > I've ordered a couple to test them. > > > https://straval.com/catlist-back-pressure-regulators/back-pressure-regul > ator-piston-angle-valve-threaded-bps-05 > > > > > ========== > > rget="_blank">http://www.matronics.com/Navigator?Yak-List > ========== > http://forums.matronics.com/ > ========== > le, List Admin. > ="_blank">http://www.matronics.com/contribution > ========== > > > ========== > rget="_blank">http://www.matronics.com/Navigator?Yak-List > ========== > http://forums.matronics.com/ > ========== > le, List Admin. > ="_blank">http://www.matronics.com/contribution > ========== > > > * > > > * > > > ========== > rget="_blank">http://www.matronics.com/Navigator?Yak-List > =================================== > http://forums.matronics.com > =================================== > le, List Admin. > ="_blank">http://www.matronics.com/contribution > =================================== > > > * > > href="http://www.matronics.com/Navigator?Yak-List">http://www.matronics.com/Navigator?Yak-List > href="http://forums.matronics.com">http://forums.matronics.com > href="http://www.matronics.com/contribution">http://www.matronics.com/c > * > > *http://www.ma==================== > > * > > > * > > > * ________________________________ Message 13 ____________________________________ Time: 08:32:12 AM PST US Subject: RE: Yak-List: Air system 'stuff' From: "Bitterlich, Mark G CIV NAVAIR, WD" Yes, it should be polarity sensitive even though I have never tested it to that effect. We are talking DC here, so if we reverse the polarity, the magnetic field will reverse as well. I never realized that the plug could be connected both ways. Hmmm. Connect an ohm-meter to the two pins on the solenoid and check to at least see that you do not have an open, meaning make sure coil is not dead. Check cockpit volt meter and make sure when you press the start button that you are not dropping voltage below say ... 20 volts minimum... actually should stay up around 23 VDC or so, but even 20 volts (when pushing the start button) should open the valve. You checked for voltage to one pin on the feed plug, but did you check the other pin with an ohm-meter and make sure it has a good reading to ground? If you really want to be sure, connect about a 20 watt (or so) light bulb across the two pins in the plug and make sure it lights when you hit start. Realize that when you check for power on a plug like you just did, it is being checked with zero load (no current flow). So if you have a ton of resistance in the wire, it will still read the exact voltage that you want to see. Meaning, voltage drop equals current times resistance. So if E=IR and you have zero current ... zero times anything is zero, so you will have no voltage drop. This rarely is a concern because wires normally just fail open. But once in awhile it can really bite you in the tail if you are not aware of it. In any case, putting a light bulb across the two pins on the feed plug puts a load on the wires. If the bulb lights up bright, you have good wiring, if it glows dimly, you have high resistance somewhere. Simple. Did you take it out and clean it because you were already having a problem? Or just because ..... Usually problems of this nature are not with the aircraft wiring, but with the device itself. A lot has already been writing about these things.. you might want to check the archives. Mark p.s. Doug Sapp has new ones. -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of bill wade Sent: Tuesday, June 11, 2013 10:51 Subject: Re: Yak-List: Air system 'stuff' As were talking about air system stuff Does any one know if the air start valve solenoid is polarity sensitive? The wire plug connector can be attached both ways. Took it out cleaned it now it doesn't work I have voltage at the wire when start button is pushed, valve works when the lever is pushed down? Just ordered new Batteries. Bill Wade From: Mark Davis Sent: Tuesday, June 11, 2013 10:20 AM Subject: Re: Yak-List: Air system 'stuff' The good news with a YAK-52 is that if you kill the mags and land flaps up you likely will do very little damage to the aircraft in a gear up landing. This of course would depend on a GIB that understands this concept and actually gives a s#%t at the time! Mark Davis N44YK ----- Original Message ----- From: John Nolan To: yak-list@matronics.com Sent: Tuesday, June 11, 2013 6:55 AM Subject: Re: Yak-List: Air system 'stuff' When removing any components from the aft cockpit I would consider the possibility of pilot incapacitation in the forward cockpit with a person in the back. Regards, John Nolan On Tue, Jun 11, 2013 at 7:55 AM, A. Dennis Savarese wrote: Since neither the CJ nor the Yak 52, which have 100% identical gear and flap selectors for both front and rear cockpits, the rear cockpit gear and flap selectors are no longer used as was originally intended; as primary trainers. Therefore gear and flap selectors in the rear cockpit serve no functional benefit other than to pass the air pressure through them to the front cockpit. Why not fabricate a 3 valve and 5 valve bypass 'block' which could replace both of these "rarely ever used" components and eliminate potential failures in the pneumatic system? This is not difficult to do. In fact, I am pretty sure Jim Goolsby modified his rear gear selector and created a bypass. Thus he eliminated the potential failure of the unit. I personally fabricated a bypass configuration for one Yak 52 and completely removed the rear gear selector. Replacing a rear gear selector in a Yak 52 is far more difficult than on a CJ because the CJ's gear selector can be accessed from behind the front seat. In the Yak 52 you need a 10 year old skinny kid to get under the instrument panel. If you have never disassembled a rear gear selector after it has started leaking, you would not believe the rust and junk that accumulates inside this piece of equipment when it is never used. And many folks never even test them during the condition inspection. So they just sit there and corrode over time. My contention is, if it is not used and can and will cause pneumatic system problems, why not remove it from the system and eliminate the potential problem once and for all. Dennis A. Dennis Savarese 334-285-6263 334-546-8182 (mobile) http://www.yak-52.com/ Skype - Yakguy1 On 6/10/2013 4:41 PM, doug sapp wrote: Mark, It has been my experience that 75% or more of the failures of QSF2A valves (3 port valves to you 52 types), and 12-5522-00 (5 port valve) are caused not by moisture/rust but by grit and or pieces of rusted springs. Years of rusty springs and poor maintenance has resulted in the majority of the air systems out there being contaminated to some degree. To combat the base problem we switched to all stainless steel springs in most all of our valves quite some time ago. The secondary problem of contaminated pneumatic problems is harder to solve as flushing the system out is very difficult. We are experimenting with the installation of a second stainless steel desiccant filter installed just prior to the rear gear valve, if successful this should vastly extend the life of these expensive valves. Best, Doug On Mon, Jun 10, 2013 at 12:10 PM, Bitterlich, Mark G CIV NAVAIR, WD >> wrote: Mark G CIV NAVAIR, WD" >> Thanks for the expert advice Doug. I had never even considered that. By the way, there is an air filter of sorts in the YAK-50. It is located on the "T" air divider area where all the check valves are located (four of them). It appears to be a circular device with fittings at both ends and is possibly filled with something like steel wool. In any case, whatever was in mine came all to pieces and junked up the check valves. Again: Good advice on a better filter. Hmmm. Mark -----Original Message----- From: owner-yak-list-server@matronics.com > [mailto:owner-yak-list-server@matronics.com >] On Behalf Of doug sapp Sent: Monday, June 10, 2013 14:44 To: yak-list@matronics.com Subject: Re: Yak-List: Air system 'stuff' Cory, Mark is correct in all he said, however the valve which you have selected would be somewhat prone to problems if your upstream air system is not 100% free of foreign material, such as old std steel rusted spring parts, dirt, grease, etc. These valves are intended for use in clean environments, not the somewhat dirtier systems of the CJ6. Placing the valve just after a high quality filter would both extend it's life and lower the probability of reoccurring maintenance issues I'm sure. Best, Doug On Mon, Jun 10, 2013 at 11:12 AM, Bitterlich, Mark G CIV NAVAIR, WD >> wrote: "Bitterlich, Mark G CIV NAVAIR, WD" >> Cory, Sorry to disagree, but just in the details. The valves that you referenced are indeed pop-off valves. They open to release or by-pass pressure to keep at a maintained value, exactly as does the pressure relief valve that is in there now. That said, they are of much better design and should work much better than the ones that are in there now, if you get one rated for the pressure and flow for our application. Taken from the company's web site: "Although this valve operates very similar to a relief valve which is usually designed to release pressure quickly as soon as the set pressure is exceeded , this valve is designed to relieve pressure more gradually with changes in flow resulting in fewer pressure spikes when the valve opens and closes. This is a direct-acting valve with an adjustable spring operating against a piston subjected to the inlet pressure of the valve. Increasing the spring compression will increase the system or line pressure to be maintained. Reducing the spring compression will reduce the system or line pressure to be maintained. " The summation: "An increase in system pressure beyond the set point will cause the main valve to open and relieve or bypass the excess pressure." This is EXACTLY how our present valves work, but these are easier to get and maintain. Mark p.s. Probably a darn good replacement. -----Original Message----- From: owner-yak-list-server@matronics.com > [mailto:owner-yak-list-server@matronics.com >] On Behalf Of Cory Robin Sent: Sunday, June 09, 2013 10:09 To: yak-list@matronics.com Subject: Re: Yak-List: Air system 'stuff' I found a source of a back pressure relief valve. Rather than it popping off and reducing the pressure, it maintains the pressure at your pre-set value. I've ordered a couple to test them. https://straval.com/catlist-back-pressure-regulators/back-pressure-regul ator-piston-angle-valve-threaded-bps-05 > ========== rget="_blank">http://www.matronics.com/Navigator?Yak-List ========== http://forums.matronics.com/ ========== le, List Admin. ="_blank">http://www.matronics.com/contribution ========== ========== rget="_blank">http://www.matronics.com/Navigator?Yak-List ========== http://forums.matronics.com/ ========== le, List Admin. ="_blank">http://www.matronics.com/contribution ========== * * ========== rget="_blank">http://www.matronics.com/Navigator?Yak-List =================================== http://forums.matronics.com =================================== le, List Admin. ="_blank">http://www.matronics.com/contribution =================================== href="http://www.matronics.com/Navigator?Yak-List">http://www.matronics. com/Navigator?Yak-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c ________________________________ Message 14 ____________________________________ Time: 02:18:42 PM PST US From: bill wade Subject: Re: Yak-List: Air system 'stuff' Actually Mark-I've been having problem's-building air and a friend clea ned his air starter and-reported very good results on higher RPM when sta rting so I thought-as I'm messing with the air system and I've read it sh ould be cleaned periodically (first time in 13 years)-I would take a look , falls under if it isn't broke don't fix it! actually it was very clean. -As for the building air seems to be from the pump to the check valve and still chasing it, looking for a flex hose from the pump to the snot valve. I will try the bulb thing and check for an open in solenoid. Thanks=0ABill Wade=0A =0A=0A________________________________=0A From: "Bitterlich, Mark G CIV NAVAIR, WD" =0ATo: yak-list@matronics.com =0ASent: Tuesday, June 11, 2013 11:29 AM=0ASubject: RE: Yak-List: Air syste NAVAIR, WD" =0A=0AYes, it should be polarity sen sitive even though I have never tested it=0Ato that effect.- We are talki ng DC here, so if we reverse the polarity,=0Athe magnetic field will revers e as well.- I never realized that the plug=0Acould be connected both ways .- Hmmm.- =0A=0AConnect an ohm-meter to the two pins on the solenoid an d check to at=0Aleast see that you do not have an open, meaning make sure c oil is not=0Adead.- =0A=0ACheck cockpit volt meter and make sure when you press the start button=0Athat you are not dropping voltage below say ... 2 0 volts minimum...=0Aactually should stay up around 23 VDC or so, but even 20 volts (when=0Apushing the start button) should open the valve.- =0A=0A You checked for voltage to one pin on the feed plug, but did you check=0Ath e other pin with an ohm-meter and make sure it has a good reading to=0Agrou nd?- If you really want to be sure, connect about a 20 watt (or so)=0Alig ht bulb across the two pins in the plug and make sure it lights when=0Ayou hit start.- Realize that when you check for power on a plug like you=0Aju st did, it is being checked with zero load (no current flow).- So if=0Ayo u have a ton of resistance in the wire, it will still read the exact=0Avolt age that you want to see.- Meaning, voltage drop equals current=0Atimes r esistance.- So if E=IR and you have zero current ... zero times=0Aanyth ing is zero, so you will have no voltage drop.- This rarely is a=0Aconcer n because wires normally just fail open.- But once in awhile it=0Acan rea lly bite you in the tail if you are not aware of it.- =0A=0AIn any case, putting a light bulb across the two pins on the feed plug=0Aputs a load on the wires. If the bulb lights up bright, you have good=0Awiring, if it glow s dimly, you have high resistance somewhere.- Simple.=0A=0A=0ADid you tak e it out and clean it because you were already having a=0Aproblem?- Or ju st because .....- Usually problems of this nature are not=0Awith the airc raft wiring, but with the device itself.- A lot has already=0Abeen writin g about these things.. you might want to check the archives.=0A=0A=0A=0AMar k=0A=0Ap.s. Doug Sapp has new ones.- =0A=0A-----Original Message-----=0AF rom: owner-yak-list-server@matronics.com=0A[mailto:owner-yak-list-server@ma tronics.com] On Behalf Of bill wade=0ASent: Tuesday, June 11, 2013 10:51=0A =0AAs were talking about air system stuff =0ADoes any one know if the air s tart valve solenoid is polarity sensitive?=0AThe wire plug connector can be attached both ways. Took it out cleaned=0Ait now it doesn't work I have vo ltage at the wire when start button is=0Apushed, valve works when the lever is pushed down? Just ordered new=0ABatteries.=0ABill Wade=0A=0AFrom: Mark Davis =0ATo: yak-list@matronics.com =0ASent: Tuesday, June 11, 2013 10:20 AM=0ASubject: Re: Yak-List: Air system 'stuff'=0A=0A =0AThe good news with a YAK-52 is that if you kill the mags and land flaps =0Aup you likely will do very little damage to the aircraft in a gear up=0A landing.- This of course would depend on a GIB that understands this=0Aco ncept and actually gives a s#%t at the time!=0A=0AMark Davis=0AN44YK=0A=0A =0A=0A--- ----- Original Message ----- =0A--- From: John Nolan - =0A--- To: yak-list@matronics.c om =0A--- Sent: Tuesday, June 11, 2013 6:55 AM=0A--- Subject: R e: Yak-List: Air system 'stuff'=0A=0A--- When removing any components from the aft cockpit I would=0Aconsider the possibility of pilot incapacit ation in the forward cockpit=0Awith a person in the back. =0A=0A--- R egards,=0A=0A--- John Nolan=0A--- =0A=0A--- =0A=0A=0A- -- On Tue, Jun 11, 2013 at 7:55 AM, A. Dennis Savarese=0A wrote:=0A--- =0A=0A--- --- --> Yak-List m essage posted by: "A. Dennis Savarese"=0A=0A --- --- =0A--- --- Since neither the CJ nor the Yak 52, which have 100%=0Aidentical gear and flap selectors for both front and rear cockpits, the=0Arear cockpit gear and flap selectors are no longer us ed as was=0Aoriginally intended; as primary trainers. Therefore gear and fl ap=0Aselectors in the rear cockpit serve no functional benefit other than t o=0Apass the air pressure through them to the front cockpit.- Why not=0A fabricate a 3 valve and 5 valve bypass 'block' which could replace both=0Ao f these "rarely ever used" components and eliminate potential failures=0Ain the pneumatic system?=0A--- --- =0A--- --- This is not difficult to do.- In fact, I am pretty sure=0AJim Goolsby modified h is rear gear selector and created a bypass. Thus=0Ahe eliminated the potent ial failure of the unit.- I personally=0Afabricated a bypass configuratio n for one Yak 52 and completely removed=0Athe rear gear selector.- Replac ing a rear gear selector in a Yak 52 is=0Afar more difficult than on a CJ b ecause the CJ's gear selector can be=0Aaccessed from behind the front seat. - In the Yak 52 you need a 10 year=0Aold skinny kid to get under the inst rument panel.=0A--- --- =0A--- --- If you have neve r disassembled a rear gear selector=0Aafter it has started leaking, you wou ld not believe the rust and junk=0Athat accumulates inside this piece of eq uipment when it is never used.=0AAnd many folks never even test them during the condition inspection.- So=0Athey just sit there and corrode over tim e.=0A--- --- =0A--- --- My contention is, if it is not used and can and will=0Acause pneumatic system problems, why not remove it from the system and=0Aeliminate the potential problem once and for all. =0A--- --- Dennis=0A--- --- =0A--- --- A. Dennis Savarese=0A--- --- 334-285-6263=0A--- --- 334-546-8182 (mobile)=0A--- --- http://www.yak-52.com/=0A- -- --- Skype - Yakguy1=0A--- --- =0A--- -- - On 6/10/2013 4:41 PM, doug sapp wrote:=0A--- --- =0A=0A- -- --- --- Mark,=0A--- --- --- It has bee n my experience that 75% or more of=0Athe failures of QSF2A valves (3 port valves to you 52 types), and=0A12-5522-00 (5 port valve) are caused not by moisture/rust but by grit=0Aand or pieces of rusted springs.- Years of ru sty springs and poor=0Amaintenance has resulted in the majority of the air systems out there=0Abeing contaminated to some degree.- To combat the bas e problem we=0Aswitched to all stainless steel springs in most all of our v alves quite=0Asome time ago.- The secondary problem of contaminated pneum atic problems=0Ais harder to solve as flushing the system out is very diffi cult.- We are=0Aexperimenting with the installation of a second stainless steel=0Adesiccant filter installed just prior to the rear gear valve, if =0Asuccessful this should vastly extend the life of these expensive valves. =0A--- --- --- =0A--- --- --- Best,=0A --- --- --- Doug=0A--- --- --- =0A- -- --- --- On Mon, Jun 10, 2013 at 12:10 PM, Bitterlich,=0A Mark G CIV NAVAIR, WD >>=0Awrote:=0A--- --- --- =0A--- --- --- - - --> Yak-List message po sted by: "Bitterlich,=0AMark G CIV NAVAIR,=0A--- --- --- - - WD" >>=0A--- --- --- =0A- -- --- --- - - Thanks for the expert advice Doug.- I had=0Anever even considered that.=0A--- --- --- =0A-- - --- --- - - By the way, there is an air filter of sorts =0Ain the YAK-50.- It is=0A--- --- --- - - located on the "T" air divider area where=0Aall the check valves are=0A--- --- --- - - located (four of them).- It appears to be a =0Acircular device with=0A--- --- --- - - fittings at both ends and is possibly filled=0Awith something like steel=0A--- --- --- - - wool.- In any case, whatever was in mine=0Aca me all to pieces and junked=0A--- --- --- - - up the check valves.=0A--- --- --- =0A--- --- -- - - - Again: Good advice on a better filter.=0AHmmm.=0A--- - -- --- =0A--- --- --- - - Mark=0A--- --- --- =0A--- --- --- =0A--- --- --- - - -----Original Message-----=0A--- --- -- - - - From: owner-yak-list-server@matronics.com=0A =0A--- --- --- - - >=0A--- --- --- - - [mailto:owner-yak-list-se rver@matronics.com=0A =0A-- - --- --- - - >] On Behalf Of doug sapp =0A--- --- --- - - Sent: Monday, June 10, 2013 14:44 =0A--- --- --- - - To: yak-list@matronics.com=0A=0A--- --- --- - - Subject: Re: Yak-List: Air system 'stuff'=0A--- --- --- =0A-- - --- --- - - Cory,=0A--- --- --- - - Mark is correct in all he said, however the=0Avalve which you have=0A --- --- --- - - selected would be somewhat prone to p roblems=0Aif your upstream air=0A--- --- --- - - syst em=0A--- --- --- - - is not 100% free of foreign mate rial, such=0Aas old std steel rusted=0A--- --- --- - - spring parts, dirt, grease, etc.- These=0Avalves are intended for use in=0A--- --- --- - - clean environments, not the som ewhat dirtier=0Asystems of the CJ6.=0A--- --- --- - - Placing the valve just after a high quality=0Afilter would both extend=0A --- --- --- - - it's life and lower the probability o f=0Areoccurring maintenance issues=0A--- --- --- - - I'm sure.=0A--- --- --- =0A--- --- --- - - Best,=0A--- --- --- - - Doug=0A--- - -- --- =0A--- --- --- =0A--- --- --- - - On Mon, Jun 10, 2013 at 11:12 AM,=0ABitterlich, Mark G CI V NAVAIR, WD=0A--- --- --- - - >> =0Awrote:=0A--- --- --- =0A--- --- --- =0A--- --- --- - - - - - - --> Yak-List messa ge posted by:=0A"Bitterlich, Mark G CIV=0A--- --- --- - - NAVAIR,=0A--- --- --- - - WD" >>=0A--- --- --- =0A--- --- --- - - - - - - Cory,=0A--- --- --- =0A--- - -- --- - - - - - - Sorry to disagree, but just in the =0Adetails. The valves that=0A--- --- --- - - you ref erenced are indeed pop-off valves.=0AThey open to release or=0A--- --- --- - - by-pass pressure to keep at a maintained=0Avalu e, exactly as does the=0A--- --- --- - - pressure rel ief valve that is in there now.=0AThat said, they are=0A--- --- --- - - of much=0A--- --- --- - - better d esign and should work much better=0Athan the ones that are in=0A--- --- --- - - there now, if you get one rated for the=0Apress ure and flow for our=0A--- --- --- - - application. =0A--- --- --- =0A--- --- --- - - - - - - Taken from the company's web site:=0A--- --- --- =0A--- --- --- - - - - - - "Althoug h this valve operates very=0Asimilar to a relief valve=0A--- -- - --- - - which is usually designed to release=0Apressure quick ly as soon as=0A--- --- --- - - the set=0A--- --- --- - - pressure is exceeded , this valve is=0Adesigned to relieve pressure more=0A--- --- --- - - gradually with changes in flow resulting in=0Afewer pressure spikes when=0A--- --- --- - - the valve opens and closes. This is a=0Adirect -acting valve with an=0A--- --- --- - - adjustable sp ring operating against a piston=0Asubjected to the inlet=0A--- -- - --- - - pressure of the valve. Increasing the spring=0Acompre ssion will increase=0A--- --- --- - - the system or l ine pressure to be=0Amaintained. Reducing the spring=0A--- --- --- - - compression will reduce the system or line=0Apressure to be=0A--- --- --- - - maintained. "=0A--- -- - --- =0A--- --- --- - - - - - - The summation:=0A--- --- --- =0A--- --- --- - - - - - - "An increase in system pressure=0Abeyond the set p oint will=0A--- --- --- - - cause=0A--- -- - --- - - the main valve to open and relieve or bypass=0Athe ex cess pressure."=0A--- --- --- =0A--- --- - -- - - - - - - This is EXACTLY how our present=0Avalves wor k, but these are=0A--- --- --- - - easier to get and maintain.=0A--- --- --- =0A--- --- --- - - - - - - Mark=0A--- --- --- =0A--- --- --- - - - - - - p.s.- Probably a darn good=0A replacement.=0A--- --- --- =0A--- --- -- - =0A--- --- --- - - - - - - -----Original Message-----=0A--- --- --- - - - - - - From: =0Aowner-yak-list-server@matronics.com=0A =0A--- --- --- - - >=0A- -- --- --- - - [mailto:owner-yak-list-server@matronics. com=0A =0A--- --- --- - - >] On Behalf Of Cory Robin=0A--- --- --- - - - - - - Sent: Sunday, June 09, 2013 10: 09=0A--- --- --- - - - - - - To: yak-list@mat ronics.com=0A=0A--- --- -- - - - - - - - Subject: Re: Yak-List: Air system=0A'stuff'=0A --- --- --- =0A--- --- --- - - - - - - I found a source of a back pressure=0Arelief valve.- Rather =0A--- --- --- - - than=0A--- --- -- - - - it popping off and reducing the pressure, it=0Amaintains the pr essure at=0A--- --- --- - - your pre-set value.=0A- -- --- --- =0A--- --- --- - - - - - - I've ordered a couple to test them.=0A--- --- -- - =0A--- --- --- =0A--- =0Ahttps://straval.com/ca tlist-back-pressure-regulators/back-pressure-regul=0A =0A--- -- - --- - - ator-piston-angle-valve-threaded-bps-05=0A--- =0A >=0A--- --- --- =0A--- --- --- =0A--- --- --- =0A--- --- -- - =0A--- --- --- =0A--- --- --- =0A --- --- --- =0A--- --- --- - - - - - - ============0A--- =0Arget="_blank ">http://www.matronics.com/Navigator?Yak-List=0A =0A--- --- --- - - - - - - ============0A--- --- --- - - http://forums.matronics.com/=0A--- --- --- - - - - - - ============0A--- --- -- - - - - - - - le, List Admin.=0A--- =0A="_blank">http ://www.matronics.com/contribution=0A =0A--- --- --- - - - - - - ===== =======0A--- --- --- =0A--- --- --- =0A--- --- --- =0A--- --- --- =0A--- --- --- =0A--- --- --- =0A- -- --- --- =0A--- --- --- =0A--- --- --- =0A--- --- --- =0A--- --- --- =0A--- --- --- =0A--- --- -- - - - ============0A--- =0Arget="_blank ">http://www.matronics.com/Navigator?Yak-List=0A =0A--- --- --- - - ===== =======0A--- --- --- - - http://forums.ma tronics.com/=0A--- --- --- - - ======= =====0A--- --- --- - - le, List Admin.=0A- -- =0A="_blank">http://www.matronics.com/contribution=0A =0A--- --- --- - - == ==========0A--- --- --- =0A--- --- --- =0A--- --- --- =0A--- --- --- =0A--- --- --- *=0A--- --- -- - =0A--- --- --- =0A--- --- --- *=0A --- --- --- =0A=0A=0A=0A--- --- ==== ========0A--- =0Arget="_blank">http://www.matronics.c om/Navigator?Yak-List=0A--- --- ========== ==0A--- --- http://forums.matronics.com/=0A--- -- - ======================= ==============0A--- --- le, List Admi n.=0A--- --- ="_blank">http://www.matronics.com/contribution =0A--- --- ================= ====================0A--- - -- =0A--- --- =0A--- --- =0A--- --- =0A=0A=0A--- =0A--- =0A--- =0Ahref="http://www.matroni cs.com/Navigator?Yak-List">http://www.matronics.=0Acom/Navigator?Yak-List =0A--- href="http://forums.matronics.com/">http://forums.matronics. com/=0A--- =0Ahref="http://www.matronics.com/contribution">http://w -======================== - - - - - - - - - - - - - - -Matt Dralle, List ====== ________________________________ Message 15 ____________________________________ Time: 02:32:37 PM PST US From: "A. Dennis Savarese" Subject: Re: Yak-List: Air system 'stuff' Doug Sapp has the flexible hose from the compressor output check valve banjo fitting to the snot bottle. Dennis ________________________________ From: bill wade Sent: Tue, June 11, 2013 4:19:32 PM Subject: Re: Yak-List: Air system 'stuff' Actually Mark I've been having problem's building air and a friend cleaned his air starter and reported very good results on higher RPM when starting so I thought as I'm messing with the air system and I've read it should be cleaned periodically (first time in 13 years) I would take a look, falls under if it isn't broke don't fix it! actually it was very clean. As for the building air seems to be from the pump to the check valve and still chasing it, looking for a flex hose from the pump to the snot valve. I will try the bulb thing and check for an open in solenoid. Thanks Bill Wade From: "Bitterlich, Mark G CIV NAVAIR, WD" Sent: Tuesday, June 11, 2013 11:29 AM Subject: RE: Yak-List: Air system 'stuff' Yes, it should be polarity sensitive even though I have never tested it to that effect. We are talking DC here, so if we reverse the polarity, the magnetic field will reverse as well. I never realized that the plug could be connected both ways. Hmmm. Connect an ohm-meter to the two pins on the solenoid and check to at least see that you do not have an open, meaning make sure coil is not dead. Check cockpit volt meter and make sure when you press the start button that you are not dropping voltage below say ... 20 volts minimum... actually should stay up around 23 VDC or so, but even 20 volts (when pushing the start button) should open the valve. You checked for voltage to one pin on the feed plug, but did you check the other pin with an ohm-meter and make sure it has a good reading to ground? If you really want to be sure, connect about a 20 watt (or so) light bulb across the two pins in the plug and make sure it lights when you hit start. Realize that when you check for power on a plug like you just did, it is being checked with zero load (no current flow). So if you have a ton of resistance in the wire, it will still read the exact voltage that you want to see. Meaning, voltage drop equals current times resistance. So if E=IR and you have zero current ... zero times anything is zero, so you will have no voltage drop. This rarely is a concern because wires normally just fail open. But once in awhile it can really bite you in the tail if you are not aware of it. In any case, putting a light bulb across the two pins on the feed plug puts a load on the wires. If the bulb lights up bright, you have good wiring, if it glows dimly, you have high resistance somewhere. Simple. Did you take it out and clean it because you were already having a problem? Or just because ..... Usually problems of this nature are not with the aircraft wiring, but with the device itself. A lot has already been writing about these things.. you might want to check the archives. Mark p.s. Doug Sapp has new ones. -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of bill wade Sent: Tuesday, June 11, 2013 10:51 Subject: Re: Yak-List: Air system 'stuff' As were talking about air system stuff Does any one know if the air start valve solenoid is polarity sensitive? The wire plug connector can be attached both ways. Took it out cleaned it now it doesn't work I have voltage at the wire when start button is pushed, valve works when the lever is pushed down? Just ordered new Batteries. Bill Wade From: Mark Davis Sent: Tuesday, June 11, 2013 10:20 AM Subject: Re: Yak-List: Air system 'stuff' The good news with a YAK-52 is that if you kill the mags and land flaps up you likely will do very little damage to the aircraft in a gear up landing. This of course would depend on a GIB that understands this concept and actually gives a s#%t at the time! Mark Davis N44YK ----- Original Message ----- From: John Nolan To: yak-list@matronics.com Sent: Tuesday, June 11, 2013 6:55 AM Subject: Re: Yak-List: Air system 'stuff' When removing any components from the aft cockpit I would consider the possibility of pilot incapacitation in the forward cockpit with a person in the back. Regards, John Nolan On Tue, Jun 11, 2013 at 7:55 AM, A. Dennis Savarese wrote: Since neither the CJ nor the Yak 52, which have 100% identical gear and flap selectors for both front and rear cockpits, the rear cockpit gear and flap selectors are no longer used as was originally intended; as primary trainers. Therefore gear and flap selectors in the rear cockpit serve no functional benefit other than to pass the air pressure through them to the front cockpit. Why not fabricate a 3 valve and 5 valve bypass 'block' which could replace both of these "rarely ever used" components and eliminate potential failures in the pneumatic system? This is not difficult to do. In fact, I am pretty sure Jim Goolsby modified his rear gear selector and created a bypass. Thus he eliminated the potential failure of the unit. I personally fabricated a bypass configuration for one Yak 52 and completely removed the rear gear selector. Replacing a rear gear selector in a Yak 52 is far more difficult than on a CJ because the CJ's gear selector can be accessed from behind the front seat. In the Yak 52 you need a 10 year old skinny kid to get under the instrument panel. If you have never disassembled a rear gear selector after it has started leaking, you would not believe the rust and junk that accumulates inside this piece of equipment when it is never used. And many folks never even test them during the condition inspection. So they just sit there and corrode over time. My contention is, if it is not used and can and will cause pneumatic system problems, why not remove it from the system and eliminate the potential problem once and for all. Dennis A. Dennis Savarese 334-285-6263 334-546-8182 (mobile) http://www.yak-52.com/ Skype - Yakguy1 On 6/10/2013 4:41 PM, doug sapp wrote: Mark, It has been my experience that 75% or more of the failures of QSF2A valves (3 port valves to you 52 types), and 12-5522-00 (5 port valve) are caused not by moisture/rust but by grit and or pieces of rusted springs. Years of rusty springs and poor maintenance has resulted in the majority of the air systems out there being contaminated to some degree. To combat the base problem we switched to all stainless steel springs in most all of our valves quite some time ago. The secondary problem of contaminated pneumatic problems is harder to solve as flushing the system out is very difficult. We are experimenting with the installation of a second stainless steel desiccant filter installed just prior to the rear gear valve, if successful this should vastly extend the life of these expensive valves. Best, Doug On Mon, Jun 10, 2013 at 12:10 PM, Bitterlich, Mark G CIV NAVAIR, WD >> wrote: Mark G CIV NAVAIR, WD" >> Thanks for the expert advice Doug. I had never even considered that. By the way, there is an air filter of sorts in the YAK-50. It is located on the "T" air divider area where all the check valves are located (four of them). It appears to be a circular device with fittings at both ends and is possibly filled with something like steel wool. In any case, whatever was in mine came all to pieces and junked up the check valves. Again: Good advice on a better filter. Hmmm. Mark -----Original Message----- From: owner-yak-list-server@matronics.com > [mailto:owner-yak-list-server@matronics.com >] On Behalf Of doug sapp Sent: Monday, June 10, 2013 14:44 To: yak-list@matronics.com Subject: Re: Yak-List: Air system 'stuff' Cory, Mark is correct in all he said, however the valve which you have selected would be somewhat prone to problems if your upstream air system is not 100% free of foreign material, such as old std steel rusted spring parts, dirt, grease, etc. These valves are intended for use in clean environments, not the somewhat dirtier systems of the CJ6. Placing the valve just after a high quality filter would both extend it's life and lower the probability of reoccurring maintenance issues I'm sure. Best, Doug On Mon, Jun 10, 2013 at 11:12 AM, Bitterlich, Mark G CIV NAVAIR, WD >> wrote: --> Yak-List message posted by: "Bitterlich, Mark G CIV NAVAIR, WD" >> Cory, Sorry to disagree, but just in the details. The valves that you referenced are indeed pop-off valves. They open to release or by-pass pressure to keep at a maintained value, exactly as does the pressure relief valve that is in there now. That said, they are of much better design and should work much better than the ones that are in there now, if you get one rated for the pressure and flow for our application. Taken from the company's web site: "Although this valve operates very similar to a relief valve which is usually designed to release pressure quickly as soon as the set pressure is exceeded , this valve is designed to relieve pressure more gradually with changes in flow resulting in fewer pressure spikes when the valve opens and closes. This is a direct-acting valve with an adjustable spring operating against a piston subjected to the inlet pressure of the valve. Increasing the spring compression will increase the system or line pressure to be maintained. Reducing the spring compression will reduce the system or line pressure to be maintained. " The summation: "An increase in system pressure beyond the set point will cause the main valve to open and relieve or bypass the excess pressure." This is EXACTLY how our present valves work, but these are easier to get and maintain. Mark p.s. Probably a darn good replacement. -----Original Message----- From: owner-yak-list-server@matronics.com > [mailto:owner-yak-list-server@matronics.com >] On Behalf Of Cory Robin Sent: Sunday, June 09, 2013 10:09 To: yak-list@matronics.com Subject: Re: Yak-List: Air system 'stuff' I found a source of a back pressure relief valve. Rather than it popping off and reducing the pressure, it maintains the pressure at your pre-set value. I've ordered a couple to test them. https://straval.com/catlist-back-pressure-regulators/back-pressure-regul ator-piston-angle-valve-threaded-bps-05 > ========== rget="_blank">http://www.matronics.com/Navigator?Yak-List ========== http://forums.matronics.com/ ========== le, List Admin. ="_blank">http://www.matronics.com/contribution ========== ========== rget="_blank">http://www.matronics.com/Navigator?Yak-List ========== http://forums.matronics.com/ ========== le, List Admin. ="_blank">http://www.matronics.com/contribution ========== * * ========== rget="_blank">http://www.matronics.com/Navigator?Yak-List ========== http://forums.matronics.com/ ========== le, List Admin. ="_blank">http://www.matronics.com/contribution ========== href="http://www.matronics.com/Navigator?Yak-List">http://www.matronics. com/Navigator?Yak-List href="http://forums.matronics.com/">http://forums.matronics.com/ href="http://www.matronics.com/contribution">http://www.matronics.com/c = - The Yak-List Email Forum /Navigator?Yak-List" target="_blank">http://www.matronics.com/Navigator?Yp; --> http:======================== ________________________________ Message 16 ____________________________________ Time: 07:40:18 PM PST US Subject: Yak-List: Fwd: Parker pop-off in use on my CJ From: "Roger Kemp M.D." Sent from my iPad >>> >>> Mark, >>> >>> I'm using a Parker pressure relief valve on my CJ, which I obtained from Kevin Kimball. Check with them for prices if you are interested at some point. My motives in exploring this were: A. Cleaner engine compartment and; B. Longterm supportability of this particularly critical item. (I think that supplies of NOS parts will eventually dry up.); C. Thought it would be an easy installation---and it was. >>> >>> The unit was factory preset and certified to pop off at 750psi---but is easily adjustable. It also has an outlet port which I connected to an unused smoke fitting on the left exhaust stack. It is mounted on the firewall exactly where the original valve was; uses the stock CJ tubing and fittings; with the pressure inlet and check valves mounted on an AN cross. As the brass valve is heavier than the original, I drilled three holes in the firewall and added plate nuts for adel clamps to hold the valve. That was it for mods. >>> >>> This unit has proven to be reliable; stable in pressure maintenance; and much cleaner in operation due to venting the bypass crud to the exhaust...rather than dumping it on the firewall. >>> >>> I am out of the county and out of memory re: the Parker part #--- but will be back in country late next week. I will be glad to post photos of my installation on the list should anyone be interested. >>> >>> Buddy Moman >>> Northport, Alabama >>> N5616N >>> >>> >>> >>> >>> >>> Sent from my iPad ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message yak-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Yak-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/yak-list Browse Digests http://www.matronics.com/digest/yak-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.