---------------------------------------------------------- Yak-List Digest Archive --- Total Messages Posted Wed 01/22/20: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:22 PM - CJ6 low main pressure (Harv) 2. 02:44 PM - Re: CJ6 low main pressure (Mark Pennington) 3. 03:18 PM - Re: CJ6 low main pressure (Greg Wrobel) 4. 04:11 PM - Re: CJ6 low main pressure (Mark Pennington) 5. 11:29 PM - Re: CJ6 low main pressure (Harv) 6. 11:39 PM - CJ Mods (Daniel Sallee) ________________________________ Message 1 _____________________________________ Time: 02:22:59 PM PST US Subject: Yak-List: CJ6 low main pressure From: "Harv" Good evening Have a slight air issue on my CJ. With system charged from external scuba bottle, pop off valve heard at 5kgcm gauge reading with main air closed but open the main air valve and pressure on gauge drops immediately to 2kgcm? I've not done too much investigation as yet but welcome ideas with likely culprits..... Looking at the CJ air schematic I see that there could be a leak could be from a few places. 1. Belly snot valve 2. Gear Rams (extend side) 3. Check valve on firewall 4. QDF-1 Start valve 5. QS-1 Brake pressure reducing valve? (Do these leak to atmos?) Thanks in advance. Harv Read this topic online here: http://forums.matronics.com/viewtopic.php?p=494397#494397 ________________________________ Message 2 _____________________________________ Time: 02:44:24 PM PST US From: Mark Pennington Subject: Re: Yak-List: CJ6 low main pressure Harv That all sounds normal to me. If the main air valve is closed. And you charge the system. You are excluding the 12L main air bottle from the system. When you open the main air valve you put pressure on the main air tank. That would look just like you see. A pressure drop. When charging the system with the external bottle have the main air valve open. Charge the entire system. Close the main air valve. If your CJ is like most the air will bleed off to nothing over time. That=99s normal. (Wish it wasn=99t ) When you open the main air valve. It will charge the system. When you start the plane. The compressor will fill the bottle and keep the system running. Mark Pennington 804 399 4224. N621 CJ If you have questions feel free to call. On Wed, Jan 22, 2020 at 5:28 PM Harv wrote: > > Good evening > > Have a slight air issue on my CJ. > > With system charged from external scuba bottle, pop off valve heard at > 5kgcm gauge reading with main air closed but open the main air valve and > pressure on gauge drops immediately to 2kgcm? > > I've not done too much investigation as yet but welcome ideas with likely > culprits..... > > Looking at the CJ air schematic I see that there could be a leak could be > from a few places. > > 1. Belly snot valve > 2. Gear Rams (extend side) > 3. Check valve on firewall > 4. QDF-1 Start valve > 5. QS-1 Brake pressure reducing valve? (Do these leak to atmos?) > > Thanks in advance. > > Harv > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=494397#494397 > > =========== =========== =========== =========== =========== =========== > > ________________________________ Message 3 _____________________________________ Time: 03:18:06 PM PST US From: Greg Wrobel Subject: Re: Yak-List: CJ6 low main pressure Mark is correct. With main air valve closed you will only charge the lines and the emergency tank. Remember to open main air valve when filling. Think of the main air valve as a shut off valve to main air tank only. Tank may be in the tail but the open valve (main shutoff valve) is in cockpit. Also, when using scuba air to fill system, crack the scuba valve and never open it fully. Your dealing with a 3000 psi scuba bottle dumping air into a 750 psi system. If the pop off valve can't react fast enough or fails to open, something is going to blow. Jump on the wing and watch the main air and emergncy air gages. In addition go to Doug's website and he has an Excellent schematic of the air system for download. I had it blown up 18x24 and laminated. Great in the hangar. Also on my phone for reference when on the road. Lastly, Mark says the system bleeds down quickly. What he meant to add is in a perfect world when you shut the main air off you are isoalating the main tank from system and if all your check valves are working the air that bleeds off is what's trapped in the lines the main tank and emergency tank should stay full or to wherever the pop off valve is set. Greg On Wed, Jan 22, 2020, 17:48 Mark Pennington < pennington.construction.inc.1@gmail.com> wrote: > Harv > > That all sounds normal to me. If the main air valve is closed. And you > charge the system. You are excluding the 12L main air bottle from the > system. > > When you open the main air valve you put pressure on the main air tank. > That would look just like you see. A pressure drop. > > When charging the system with the external bottle have the main air valve > open. Charge the entire system. Close the main air valve. If your CJ is > like most the air will bleed off to nothing over time. > > That=99s normal. (Wish it wasn=99t ) > > When you open the main air valve. It will charge the system. When you > start the plane. The compressor will fill the bottle and keep the > system running. > > Mark Pennington > 804 399 4224. > N621 CJ > > If you have questions feel free to call. > > > On Wed, Jan 22, 2020 at 5:28 PM Harv wrote: > >> >> Good evening >> >> Have a slight air issue on my CJ. >> >> With system charged from external scuba bottle, pop off valve heard at >> 5kgcm gauge reading with main air closed but open the main air valve and >> pressure on gauge drops immediately to 2kgcm? >> >> I've not done too much investigation as yet but welcome ideas with likel y >> culprits..... >> >> Looking at the CJ air schematic I see that there could be a leak could b e >> from a few places. >> >> 1. Belly snot valve >> 2. Gear Rams (extend side) >> 3. Check valve on firewall >> 4. QDF-1 Start valve >> 5. QS-1 Brake pressure reducing valve? (Do these leak to atmos?) >> >> Thanks in advance. >> >> Harv >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=494397#494397 >> >> >> >> >> >> >> ========== >> br> fts!) >> r> > rel="noreferrer" target="_blank"> >> http://www.matronics.com/contribution >> -Matt Dralle, List Admin. >> ========== >> List" rel="noreferrer" target="_blank"> >> http://www.matronics.com/Navigator?Yak-List >> ========== >> FORUMS - >> eferrer" target="_blank">http://forums.matronics.com >> ========== >> WIKI - >> errer" target="_blank">http://wiki.matronics.com >> ========== >> b Site - >> -Matt Dralle, List Admin. >> rel="noreferrer" target="_blank">http://www.matronics.com/contributi on >> ========== >> >> >> >> ________________________________ Message 4 _____________________________________ Time: 04:11:06 PM PST US From: Mark Pennington Subject: Re: Yak-List: CJ6 low main pressure Excellent Summation. =F0=9F=91=8D=F0=9F=91=8D=F0=9F=91=8D Mark On Wed, Jan 22, 2020 at 6:22 PM Greg Wrobel wrote: > Mark is correct. With main air valve closed you will only charge the line s > and the emergency tank. Remember to open main air valve when filling. Thi nk > of the main air valve as a shut off valve to main air tank only. Tank may > be in the tail but the open valve (main shutoff valve) is in cockpit. > > Also, when using scuba air to fill system, crack the scuba valve and > never open it fully. Your dealing with a 3000 psi scuba bottle dumping ai r > into a 750 psi system. If the pop off valve can't react fast enough or > fails to open, something is going to blow. Jump on the wing and watch the > main air and emergncy air gages. In addition go to Doug's website and h e > has an Excellent schematic of the air system for download. I had it blown > up 18x24 and laminated. Great in the hangar. Also on my phone for referen ce > when on the road. > > Lastly, Mark says the system bleeds down quickly. What he meant to add is > in a perfect world when you shut the main air off you are isoalating the > main tank from system and if all your check valves are working the air th at > bleeds off is what's trapped in the lines the main tank and emergency tan k > should stay full or to wherever the pop off valve is set. > > Greg > > On Wed, Jan 22, 2020, 17:48 Mark Pennington < > pennington.construction.inc.1@gmail.com> wrote: > >> Harv >> >> That all sounds normal to me. If the main air valve is closed. And you >> charge the system. You are excluding the 12L main air bottle from the >> system. >> >> When you open the main air valve you put pressure on the main air tank. >> That would look just like you see. A pressure drop. >> >> When charging the system with the external bottle have the main air valv e >> open. Charge the entire system. Close the main air valve. If your CJ is >> like most the air will bleed off to nothing over time. >> >> That=99s normal. (Wish it wasn=99t ) >> >> When you open the main air valve. It will charge the system. When you >> start the plane. The compressor will fill the bottle and keep the >> system running. >> >> Mark Pennington >> 804 399 4224. >> N621 CJ >> >> If you have questions feel free to call. >> >> >> >> On Wed, Jan 22, 2020 at 5:28 PM Harv wrote: >> >>> >>> Good evening >>> >>> Have a slight air issue on my CJ. >>> >>> With system charged from external scuba bottle, pop off valve heard at >>> 5kgcm gauge reading with main air closed but open the main air valve an d >>> pressure on gauge drops immediately to 2kgcm? >>> >>> I've not done too much investigation as yet but welcome ideas with >>> likely culprits..... >>> >>> Looking at the CJ air schematic I see that there could be a leak could >>> be from a few places. >>> >>> 1. Belly snot valve >>> 2. Gear Rams (extend side) >>> 3. Check valve on firewall >>> 4. QDF-1 Start valve >>> 5. QS-1 Brake pressure reducing valve? (Do these leak to atmos?) >>> >>> Thanks in advance. >>> >>> Harv >>> >>> >>> >>> >>> Read this topic online here: >>> >>> http://forums.matronics.com/viewtopic.php?p=494397#494397 >>> >>> >>> >>> >>> >>> >>> ========== >>> br> fts!) >>> r> > rel="noreferrer" target="_blank"> >>> http://www.matronics.com/contribution >>> -Matt Dralle, List Admin. >>> ========== >>> List" rel="noreferrer" target="_blank"> >>> http://www.matronics.com/Navigator?Yak-List >>> ========== >>> FORUMS - >>> eferrer" target="_blank">http://forums.matronics.com >>> ========== >>> WIKI - >>> errer" target="_blank">http://wiki.matronics.com >>> ========== >>> b Site - >>> -Matt Dralle, List Admin. >>> rel="noreferrer" target="_blank">http://www.matronics.com/contribut ion >>> ========== >>> >>> >>> >>> ________________________________ Message 5 _____________________________________ Time: 11:29:37 PM PST US Subject: Yak-List: Re: CJ6 low main pressure From: "Harv" Thanks for the replies I should have added that I did open the main air at one point to charge the system but I fear my scuba bottle was somewhat depleted and couldn't bring the whole system to operating pressure as in the end I had it's valve fully open and couldn't hear leaking or pop the PRV. I've put the bottle in for service at the local dive shop, will try again and report back. Touch wood my system has been very good since we rebuild it with stainless check valves, new flexible lines, snot pots and actuators in 2013 from Doug Sapp. Happy flying Harv Read this topic online here: http://forums.matronics.com/viewtopic.php?p=494407#494407 ________________________________ Message 6 _____________________________________ Time: 11:39:50 PM PST US From: Daniel Sallee Subject: Yak-List: CJ Mods Hello everyone. Used to have a CJ, sold and looking at a nicer one right now for purchase. Curious about a couple mods I havent been able to find info on. Does anyone still make any sort of clean kit for them? Oil shutoff valve or intake tube drains? Honestly more concerned about hydraulic locks than clean. What about the seal for the rear canopy? Thanks! Daniel Sallee ------------------------------------------------------------------------------------- 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.