---------------------------------------------------------- Yak-List Digest Archive --- Total Messages Posted Sun 02/20/11: 12 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:30 AM - Re: cnc cutting for inst panel (keithmckinley) 2. 07:49 AM - Re: Yak 52 Air Leaks (Vic) 3. 09:24 AM - Re: Re: Yak 52 Air Leaks (Walter Lannon) 4. 07:19 PM - Re: Yak 52 Air Leaks (A. Dennis Savarese) 5. 07:19 PM - Re: Yak 52 Air Leaks (A. Dennis Savarese) 6. 07:20 PM - Re: Re: Yak 52 Air Leaks (A. Dennis Savarese) 7. 07:36 PM - Re: Re: Yak 52 Air Leaks (A. Dennis Savarese) 8. 07:56 PM - Oil Temp Question (John Sykes) 9. 08:07 PM - Re: Oil Temp Question (A. Dennis Savarese) 10. 08:13 PM - Re: Oil Temp Question (Eric Wobschall) 11. 08:14 PM - Re: Oil Temp Question (Eric Wobschall) 12. 08:24 PM - Re: Oil Temp Question (Eric Wobschall) ________________________________ Message 1 _____________________________________ Time: 06:30:40 AM PST US Subject: Yak-List: Re: cnc cutting for inst panel From: "keithmckinley" Doug Sapp has those blank panels custom made. Jeff I sent you a PM. Keith -------- Keith McKinley 700HS KFIT Read this topic online here: http://forums.matronics.com/viewtopic.php?p=331607#331607 ________________________________ Message 2 _____________________________________ Time: 07:49:19 AM PST US Subject: Yak-List: Re: Yak 52 Air Leaks From: "Vic" Hello, the question here was, where does the air go when the main shut-off valve is closed ? Vic Read this topic online here: http://forums.matronics.com/viewtopic.php?p=331612#331612 ________________________________ Message 3 _____________________________________ Time: 09:24:46 AM PST US From: Walter Lannon Subject: Re: Yak-List: Re: Yak 52 Air Leaks Usually past the corroded valve cone (and/or seat) in the main air valve. >From there into the operating system where it will find a leak path to atmosphere. Doug has new stainless steel cones to fix that problem. Of course there are other things to check but not very many. Leaking main air tank or fittings, pipeline cracks, bad flares, cracked sleeves. cracked flare nuts. Since there is only one pipeline this is easy. Walt ----- From: "Vic" Sent: Sunday, February 20, 2011 7:46 AM Subject: Yak-List: Re: Yak 52 Air Leaks > > Hello, > > the question here was, where does the air go when the main shut-off valve > is closed ? > > Vic > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=331612#331612 > > > ________________________________ Message 4 _____________________________________ Time: 07:19:48 PM PST US From: "A. Dennis Savarese" Subject: Re: Yak-List: Yak 52 Air Leaks Although everything you say Hank is absolutely true, we need to remember, this is a Yak 52 leak and not a CJ6 leak. With the main air valve turned off, none of the actuators, gear selectors or any other component in the system AFTER the main air valve can discharge the main air tank on the Yak 52. Dennis On 2/19/2011 11:37 PM, Hank Gibson wrote: > Don't forget the gear and flap handles; any and all can be the culprit; > Leaking rear gear handle is common. Also, all four of your actuators (3 > gear, 1 flap) can have leak-past internally. Doug overhauled all of mine > and it helped. Finally, your two brake valves (reducing and > differential) can go bad and be a source of leakage. The Chinese made up > overhaul kits for all these air system valves and tear them down every > 100 hours I believe. Doubt many of us do that... > > Hank Gibson > 904-738-3240 Mobile > 904-213-1760 Home > hkgibby@yahoo.com > hkgibson@fnf.com > > > --- On *Sat, 2/19/11, bcbcbc //* wrote: > > > From: bcbcbc > Subject: Yak-List: Yak 52 Air Leaks > To: yak-list@matronics.com > Date: Saturday, February 19, 2011, 2:51 PM > > > > > Hello all, my Yak has a bleed down air leak that takes about 2 days, > thus making it hard to detect. I've replaced the opo off valve > piston and the air filler check valve. The main air shutoff valve > has been checked good. Thus the leak is between the air filler check > valve and the main air shutoff valve. That seems to only leave air > lines and B nuts and perhaps flared tube end cracks. Has anyone else > had a slow leak, what did you do, and what turned out to be the > problem, so I can intelligently hone in on what the problem might > be, instead of tearing everything apart. I can still fly alright > since the compressor overcomes the slow leak, but I'd like to see > that main air gage park itself at 40 or 50. The emergency side is > tight as a drum. Thanks all. > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=331551#331551 > > > > > > * > > > * ________________________________ Message 5 _____________________________________ Time: 07:19:50 PM PST US From: "A. Dennis Savarese" Subject: Re: Yak-List: Yak 52 Air Leaks Also after the main air valve. Can not discharge the main air tank with the main air valve turned off. Dennis On 2/19/2011 11:44 PM, Eric Wobschall wrote: > shuttle valves, too > > On Feb 20, 2011, at 12:37 AM, Hank Gibson wrote: > >> Don't forget the gear and flap handles; any and all can be the >> culprit; Leaking rear gear handle is common. Also, all four of your >> actuators (3 gear, 1 flap) can have leak-past internally. Doug >> overhauled all of mine and it helped. Finally, your two brake valves >> (reducing and differential) can go bad and be a source of leakage. The >> Chinese made up overhaul kits for all these air system valves and tear >> them down every 100 hours I believe. Doubt many of us do that... >> >> Hank Gibson >> 904-738-3240 Mobile >> 904-213-1760 Home >> hkgibby@yahoo.com >> hkgibson@fnf.com >> >> >> --- On *Sat, 2/19/11, bcbcbc /> >/* wrote: >> >> >> From: bcbcbc > >> Subject: Yak-List: Yak 52 Air Leaks >> To: yak-list@matronics.com >> Date: Saturday, February 19, 2011, 2:51 PM >> >> > >> >> Hello all, my Yak has a bleed down air leak that takes about 2 >> days, thus making it hard to detect. I've replaced the opo off >> valve piston and the air filler check valve. The main air shutoff >> valve has been checked good. Thus the leak is between the air >> filler check valve and the main air shutoff valve. That seems to >> only leave air lines and B nuts and perhaps flared tube end >> cracks. Has anyone else had a slow leak, what did you do, and what >> turned out to be the problem, so I can intelligently hone in on >> what the problem might be, instead of tearing everything apart. I >> can still fly alright since the compressor overcomes the slow >> leak, but I'd like to see that main air gage park itself at 40 or >> 50. The emergency side is tight as a drum. Thanks all. >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=331551#331551 >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> * >> >> >> * > > * > > > * ________________________________ Message 6 _____________________________________ Time: 07:20:12 PM PST US From: "A. Dennis Savarese" Subject: Re: Yak-List: Re: Yak 52 Air Leaks Precisely! Dennis On 2/20/2011 9:46 AM, Vic wrote: > --> Yak-List message posted by: "Vic" > > Hello, > > the question here was, where does the air go when the main shut-off valve is closed ? > > Vic > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=331612#331612 > > ________________________________ Message 7 _____________________________________ Time: 07:36:27 PM PST US From: "A. Dennis Savarese" Subject: Re: Yak-List: Re: Yak 52 Air Leaks I have found with a leaking main air valve, one can simply disconnect the output side of the valve and spray with soapy water which if leaking, will definitely bubble. Also with a leaking main air valve, the tell-tale sign is there is always brake pressure air. ie: if one were to squeeze off all the residual air using the brake handle and let it sit for a few hours, then come back and more air can be squeezed off with the brake handle, then the main air valve is leaking. One thing that is frequently overlooked in the 52 is the physical connections on the the air pressure instruments (front and rear cockpits). On the 52, the main and emergency instruments are connected before the main air valve. (Not so on the CJ6; main air instrument is connected after the main air valve). I have found the 17mm nuts on the back side of the instrument loose on a few Yak 52's. A real pain in the rear to get to AND tighten without twisting the instrument in the instrument mounting bracket. Dennis On 2/20/2011 11:19 AM, Walter Lannon wrote: > > Usually past the corroded valve cone (and/or seat) in the main air valve. >> From there into the operating system where it will find a leak path to > atmosphere. > Doug has new stainless steel cones to fix that problem. > Of course there are other things to check but not very many. Leaking > main air tank or fittings, pipeline cracks, bad flares, cracked sleeves. > cracked flare nuts. Since there is only one pipeline this is easy. > > Walt > > ----- From: "Vic" > To: > Sent: Sunday, February 20, 2011 7:46 AM > Subject: Yak-List: Re: Yak 52 Air Leaks > > >> >> Hello, >> >> the question here was, where does the air go when the main shut-off >> valve is closed ? >> >> Vic >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=331612#331612 >> >> >> >> >> >> >> >> >> >> >> > > ________________________________ Message 8 _____________________________________ Time: 07:56:05 PM PST US From: John Sykes Subject: Yak-List: Oil Temp Question I have a 1981 Yak 50 with about 188 hours TTSN Airframe and about 150 hours TTSN on the engine.- Since I have owned the aircraft the oil temp gauge has read on the high side.- I have replaced the oil temp probe and change d out the gauge with the same result.- It seems as though the high readin g is from some unknown source.- Fortunately I have access to two other Ya k 50's and two yak 52's based at my airport. A few days ago I took ambient readings from each of the oil temp gauges in each aircraft as well as the A SOS from the airport.- The following are the readings:- ASOS 23C, My Ya k 50 40C, Yak 52 #1 Front 21C, Rear 20C, Yak 52 #2 Front 21C, Rear 21C, Yak 50 #2 25C, Yak 50 #3 25C.- My aircraft's Oil Temp in ambient conditions reads some 15 to 20 degrees C higher than the reference or other similar ai rcraft. - Can anyone explain why this is or what to do to bring it more in line? - Thanks in advance and best regards, - John ________________________________ Message 9 _____________________________________ Time: 08:07:37 PM PST US From: "A. Dennis Savarese" Subject: Re: Yak-List: Oil Temp Question Sounds like you may have an oil cooler issue John. If the vernatherm is stuck in by-pass, no oil would pass through the oil cooler fins. Thus the higher oil temps. Dennis On 2/20/2011 9:53 PM, John Sykes wrote: > I have a 1981 Yak 50 with about 188 hours TTSN Airframe and about 150 > hours TTSN on the engine. Since I have owned the aircraft the oil temp > gauge has read on the high side. I have replaced the oil temp probe and > changed out the gauge with the same result. It seems as though the high > reading is from some unknown source. Fortunately I have access to two > other Yak 50's and two yak 52's based at my airport. A few days ago I > took ambient readings from each of the oil temp gauges in each aircraft > as well as the ASOS from the airport. The following are the readings: > ASOS 23C, My Yak 50 40C, Yak 52 #1 Front 21C, Rear 20C, Yak 52 #2 Front > 21C, Rear 21C, Yak 50 #2 25C, Yak 50 #3 25C. My aircraft's Oil Temp in > ambient conditions reads some 15 to 20 degrees C higher than the > reference or other similar aircraft. > Can anyone explain why this is or what to do to bring it more in line? > Thanks in advance and best regards, > John > > * > > > * ________________________________ Message 10 ____________________________________ Time: 08:13:56 PM PST US From: Eric Wobschall Subject: Re: Yak-List: Oil Temp Question Defective sender or gauge, one would think with an outside chance of defective wiring or connectors. There may be calibration of the gauge, which I assume is the usual triple gauge in Yaks. If this were CHT, the circuit has a sensitivity to the exact length of the harness and uses wire of a particular metal, I forget which. IN that case, you can't alter the wire length or it will skew the reading. Having said this, I think the oil pressure sender is a variable resister and requires power to register. I would take readings at both the sender (resistance), and at the gauge (voltage) and see where the deviation is. On Feb 20, 2011, at 10:53 PM, John Sykes wrote: > I have a 1981 Yak 50 with about 188 hours TTSN Airframe and about 150 hours TTSN on the engine. Since I have owned the aircraft the oil temp gauge has read on the high side. I have replaced the oil temp probe and changed out the gauge with the same result. It seems as though the high reading is from some unknown source. Fortunately I have access to two other Yak 50's and two yak 52's based at my airport. A few days ago I took ambient readings from each of the oil temp gauges in each aircraft as well as the ASOS from the airport. The following are the readings: ASOS 23C, My Yak 50 40C, Yak 52 #1 Front 21C, Rear 20C, Yak 52 #2 Front 21C, Rear 21C, Yak 50 #2 25C, Yak 50 #3 25C. My aircraft's Oil Temp in ambient conditions reads some 15 to 20 degrees C higher than the reference or other similar aircraft. > > Can anyone explain why this is or what to do to bring it more in line? > > Thanks in advance and best regards, > > John > > > ________________________________ Message 11 ____________________________________ Time: 08:14:27 PM PST US Subject: Re: Yak-List: Oil Temp Question From: Eric Wobschall Yeah, but his ambient temp is wrong, right? On Feb 20, 2011, at 11:04 PM, A. Dennis Savarese wrote: > > Sounds like you may have an oil cooler issue John. If the vernatherm is stuck in by-pass, no oil would pass through the oil cooler fins. Thus the higher oil temps. > Dennis > > On 2/20/2011 9:53 PM, John Sykes wrote: >> I have a 1981 Yak 50 with about 188 hours TTSN Airframe and about 150 >> hours TTSN on the engine. Since I have owned the aircraft the oil temp >> gauge has read on the high side. I have replaced the oil temp probe and >> changed out the gauge with the same result. It seems as though the high >> reading is from some unknown source. Fortunately I have access to two >> other Yak 50's and two yak 52's based at my airport. A few days ago I >> took ambient readings from each of the oil temp gauges in each aircraft >> as well as the ASOS from the airport. The following are the readings: >> ASOS 23C, My Yak 50 40C, Yak 52 #1 Front 21C, Rear 20C, Yak 52 #2 Front >> 21C, Rear 21C, Yak 50 #2 25C, Yak 50 #3 25C. My aircraft's Oil Temp in >> ambient conditions reads some 15 to 20 degrees C higher than the >> reference or other similar aircraft. >> Can anyone explain why this is or what to do to bring it more in line? >> Thanks in advance and best regards, >> John >> >> * >> >> >> * > > > > ________________________________ Message 12 ____________________________________ Time: 08:24:35 PM PST US From: Eric Wobschall Subject: Re: Yak-List: Oil Temp Question I meant in comparison to the other Yak-50 or 52.... On Feb 20, 2011, at 11:11 PM, Eric Wobschall wrote: > Defective sender or gauge, one would think with an outside chance of defective wiring or connectors. There may be calibration of the gauge, which I assume is the usual triple gauge in Yaks. If this were CHT, the circuit has a sensitivity to the exact length of the harness and uses wire of a particular metal, I forget which. IN that case, you can't alter the wire length or it will skew the reading. Having said this, I think the oil pressure sender is a variable resister and requires power to register. I would take readings at both the sender (resistance), and at the gauge (voltage) and see where the deviation is. > > > On Feb 20, 2011, at 10:53 PM, John Sykes wrote: > >> I have a 1981 Yak 50 with about 188 hours TTSN Airframe and about 150 hours TTSN on the engine. Since I have owned the aircraft the oil temp gauge has read on the high side. I have replaced the oil temp probe and changed out the gauge with the same result. It seems as though the high reading is from some unknown source. Fortunately I have access to two other Yak 50's and two yak 52's based at my airport. A few days ago I took ambient readings from each of the oil temp gauges in each aircraft as well as the ASOS from the airport. The following are the readings: ASOS 23C, My Yak 50 40C, Yak 52 #1 Front 21C, Rear 20C, Yak 52 #2 Front 21C, Rear 21C, Yak 50 #2 25C, Yak 50 #3 25C. My aircraft's Oil Temp in ambient conditions reads some 15 to 20 degrees C higher than the reference or other similar aircraft. >> >> Can anyone explain why this is or what to do to bring it more in line? >> >> Thanks in advance and best regards, >> >> John >> >> >> 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/co ntribution >> > > > > ------------------------------------------------------------------------------------- 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.