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jonboede(at)hotmail.com
Guest

Posted: Mon Oct 15, 2007 10:54 am Post subject: pneumatic cancer

I still had a minor overall leak in my air system (would take several hours 

to drop to zero once the master valve was closed) after replacing my front 

flap valve.



So I decided to be brilliant and put a couple tablespoons of WD-40 into my 

air tank.



This seems to have made the problem much, much worse.



I can hear hissing throughout the air system, even at the brand new flap and 

gear valves in the front seat, and the system won't charge up past about 25.



I have since drained the WD-40 and put a little bit of air tool oil in the 

main tank and this week I'm going to disassemble the valves, starting with 

the aforementioned brand new flap valve.



Anybody got any suggestions on what I should be looking for, mistakes to 

avoid, or just commiseration?  



Thanks,

Jon

dsavarese(at)elmore.rr.co
Guest

Posted: Mon Oct 15, 2007 11:35 am Post subject: pneumatic cancer

Charge the main air tank up and see if you have air leaking out of the 

external air fill port by spaying some soapy water at the opening.  If the 

check valve on the firewall that is on the left side of the T or Cross where 

the pop off valve is located (closest to the oil tank) is leaking, the air 

in the main air tank will leak out through the check valve and out the 

external air fill port.  The other places that can cause the leaks with the 

main air valve turned off are the B-nut fittings from the main air valve 

back to the main air tank and of course the tubes.  Also there is an O-ring 

under the large nut on the main air tank.  If that nut is loose even the 

slightest bit, the tank will leak down.



Start there and let me know what you find out.

Dennis



---

ByronMFox(at)aol.com
Guest

Posted: Mon Oct 15, 2007 11:45 am Post subject: pneumatic cancer

Jon, I could not be more empathetic!

 

 I've been chasing a small air leak in my CJ seemingly for ever. Have replaced all rubber gear airlines, overhauled the main gear actuators, front seat flap valve, all check valves and all but two overlooked shuttle valves. This leaves the nose gear and flap actuators which are hard to get at. (I'm going to leave them for poor, beleaguered Jim Selby to deal with.) Moreover, I've sprayed soapy water on ever connection I can find and chased around the airplane with Doug Sapp's fancy electronic sensor -- all to no avail!   Enough to drive an anally compulsive man mad. ...Blitz

**************************************

 See what's new at http://www.aol.com  [quote][b]

brian-1927(at)lloyd.com
Guest

Posted: Mon Oct 15, 2007 12:56 pm Post subject: pneumatic cancer

On Oct 15, 2007, at 11:50 AM, Jon Boede wrote:



 	  Quote: 	
		   So I decided to be brilliant and put a couple tablespoons of WD-40  

 into my air tank.



 This seems to have made the problem much, much worse.


	


I can think of a couple of things going on here.



1. WD-40 is a good solvent. All that old crud in the tank including  

the linseed oil they used to use for preserving the inside of the  

tank (from memory -- used to prevent rusting of the air tank in the  

CJ6A) may have dissolved in the WD-40 which was then spread  

throughout your pneumatic system the next time you opened the valve  

to let pressure into your pneumatic system.



2. WD-40 is a good solvent. Are you sure that all the seals in the  

various valves are compatible with the solvents in WD-40?



You have the right answer. Open everything up and clean it out.



BTW, the Chinese specify a cleaning solution for the air bottles. It  

is *NOT* WD-40.



I have not read the maintenance manual(s) for the Yaks but I have for  

the CJ6A. The maintenance intervals for the various components is  

surprisingly short as I recall. I suspect that there may be quite a  

few people who do not know the magnitude of the maintenance required  

by the pneumatic system and therefore, through no fault of their own,  

ignore it.



I went back and dug through my old manuals and came up with the  

following:



50 hour intervals:



1. The desiccant trap/air-filter should be serviced;



2. all actuators should be oiled. 5-10 gm of castor oil per gear  

actuator and 3-5 gm per uplock;



3. grease and swing the gear (there are lots of things to check);



4. check to see that the uplocks release at 8kg/cm^2 for the mains  

and 10 kg/cm^2 for the nosegear. (Part of the gear swing test.)



100 hour intervals:



1. disassemble, clean, and reassemble the pressure regulator (pop- 

off) valve and check valve;



2. disassemble, clean, and reassemble the bidirectional valves in the  

gear and flap systems;



3. disassemble, clean, and reassemble the start solenoid valve.



200 hour intervals:



1. before gear disassembly, check for lateral play in the nose gear  

(3mm) and fore/aft play in the main gear (8mm);



2. disassemble and check the landing gear;



3. service brakes; (I condensed lots of stuff down down to this line  

item.)



4. DISASSEMBLE AND SERVICE GEAR ACTUATORS; (my emphasis)



5. disassemble, inspect, and reassemble the shimmy damper;



6. disassemble, inspect, and reassemble the brake pressure regulator;



7. disassemble, inspect, and reassemble the brake pressure  

distributor (differential valve);



8. blow the crap out of all pneumatic lines with compressed air.



Every year (just before winter):



1. REMOVE AND CLEAN AIR BOTTLES. (My emphasis. Sounds like this is an  

annual-inspection item.)



The point I am making here is that I would be willing to bet that,  

with very few exceptions, almost everyone is guilty of failing to  

perform prescribed pneumatic system maintenance. I would be willing  

to bet that if more people adhered to the factory maintenance  

recommendations there would be many fewer troubleshooting questions  

about the pneumatic system.



And I don't know what the pneumatic system maintenance interval  

requirement is for the Yaks but I would be surprised if it was  

significantly different from the above.



One more note. If you don't have maintenance manuals for your  

aircraft, get them and read them.



--

Brian Lloyd                         3191 Western Drive

brian HYPHEN 1927 AT lloyd DOT com    Cameron Park, CA 95682

+1.916.367.2131 (voice)             +1.270.912.0788 (fax)



I fly because it releases my mind from the tyranny of petty things . . .

— Antoine de Saint-Exupéry



PGP key ID:          12095C52A32A1B6C

PGP key fingerprint: 3B1D BA11 4913 3254 B6E0  CC09 1209 5C52 A32A 1B6C

mark.bitterlich(at)navy.m
Guest

Posted: Mon Oct 15, 2007 1:08 pm Post subject: pneumatic cancer

Does anyone remember what types of sniff detectors are out there?  It

seems to me that one time I saw a really hard to find leak in a nitrogen

line.. They filled the tank with something like Argon, and then used an

Argon sniff detector that could register detection in some really loss

part per million category.  This thing could find the breath of an

ant... As long as the ant farted argon.  That kind of device will find

the most smallest of leaks out there.  I know they also make one for

Freon, but of course we can't pump that stuff into our tanks!  This

might not be as difficult as it sounds really... I just am not sure what

is out on the market and for how much. Ultrasonic leak detectors work,

but take a LOT of time. 



Mark Bitterlich

 



--

N13472(at)aol.com
Guest

Posted: Mon Oct 15, 2007 1:21 pm Post subject: pneumatic cancer

In a message dated 10/15/2007 12:47:54 P.M. Pacific Daylight Time,  ByronMFox(at)aol.com writes:

  	  Quote: 	
		  Jon, I could not be more empathetic!



I've been    chasing a small air leak in my CJ seemingly for ever. Have replaced all rubber    gear airlines, overhauled the main gear actuators, front seat flap valve, all    check valves and all but two overlooked shuttle valves. This leaves the nose    gear and flap actuators which are hard to get at. (I'm going to leave them for    poor, beleaguered Jim Selby to deal with.) Moreover, I've sprayed soapy water    on ever connection I can find and chased around the airplane with Doug Sapp's    fancy electronic sensor -- all to no avail!  Enough to drive an anally    compulsive man mad. ...Blitz



	


 

  

 So sneaking into your hangar and letting a little air out of you plane is  working! Note paid for by SOB.

rvfltd(at)televar.com
Guest

Posted: Mon Oct 15, 2007 1:50 pm Post subject: pneumatic cancer

Poked about a bit via Google for a Argon detector and could not come up 

with anything less than 3K. 

Ultrasonic sounds better all the time.  I've had mine for two years now 

and it has saved me bunches of time and trouble.  Paid 150.00 for it new 

on ebay.



Always yakin,

Doug

Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E wrote:



[quote]



Does anyone remember what types of sniff detectors are out there?  It

seems to me that one time I saw a really hard to find leak in a nitrogen

line.. They filled the tank with something like Argon, and then used an

Argon sniff detector that could register detection in some really loss

part per million category.  This thing could find the breath of an

ant... As long as the ant farted argon.  That kind of device will find

the most smallest of leaks out there.  I know they also make one for

Freon, but of course we can't pump that stuff into our tanks!  This

might not be as difficult as it sounds really... I just am not sure what

is out on the market and for how much. Ultrasonic leak detectors work,

but take a LOT of time. 



Mark Bitterlich

 



--

jonboede(at)hotmail.com
Guest

Posted: Mon Oct 15, 2007 1:53 pm Post subject: pneumatic cancer

I know that people have used Freon detectors since they can be borrowed from 

any number of refrigeration / air-conditioning folks.  I know that manical 

L-39 folks have gotten their nitrogen systems to hold for MONTHS by sniffing 

things out with a Freon detector.



Alas, my problem is not so subtle.  When I turn the main air valve on, my 

front flap valve and my back gear handle hiss noticably.  



Oh well, as Brian points out, I'm embarassingly past all 

disassemble-and-clean intervals on my pneumatic system.



Do I really want to fix things up with linseed oil?  Anybody have a better 

suggestion that will be kind to all the seals in the system?

[quote]From: "Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E" 

<mark.bitterlich(at)navy.mil>

Reply-To: yak-list(at)matronics.com

To: <yak-list(at)matronics.com>

Subject: RE: pneumatic cancer

Date: Mon, 15 Oct 2007 17:07:20 -0400




MALS-14 64E" <mark.bitterlich(at)navy.mil>



Does anyone remember what types of sniff detectors are out there?  It

seems to me that one time I saw a really hard to find leak in a nitrogen

line.. They filled the tank with something like Argon, and then used an

Argon sniff detector that could register detection in some really loss

part per million category.  This thing could find the breath of an

ant... As long as the ant farted argon.  That kind of device will find

the most smallest of leaks out there.  I know they also make one for

Freon, but of course we can't pump that stuff into our tanks!  This

might not be as difficult as it sounds really... I just am not sure what

is out on the market and for how much. Ultrasonic leak detectors work,

but take a LOT of time.



Mark Bitterlich

--

mark.bitterlich(at)navy.m
Guest

Posted: Mon Oct 15, 2007 2:12 pm Post subject: pneumatic cancer

Doug, on second thought... What would prevent us from pumping Freon into

our systems, ... Pure Freon that is, not any that has had compressor oil

already added?  Isn't Freon in that form a clean gas?  If it is, then

Freon Detectors are all over the place.  Just wondering.   I have used

the Ultrasonic deals... And they work well... But the sniff detectors do

work better.  Either one needs a nice hanger with the door closed.  



Mark

 



--

mark.bitterlich(at)navy.m
Guest

Posted: Mon Oct 15, 2007 2:22 pm Post subject: pneumatic cancer

The way I see it, you have two choices to this sudden influx of air

leaks that started with the WD-40.  



1. Take all offending parts apart and rebuild them.   

2. Get a bottle of dry nitrogen (or any other dried air source) and

regulate it at 700 psi hooked to the airplane and just cycle everything

over and over and hope you get that stuff out of three and everything

dried up enough to where it seals again.  



I cleaned out a pop-off valve one time with WD-40 and the darn thing

would not hold pressure no matter HOW much I tightened it.  Had to take

it apart and clean it out from Freon degreaser spray and then it was

fine.  



Actually you should still do step 2 first, even if you have to do step 1

later.  Just my humble opinion of course.   



Good luck. 



Mark Bitterlich

--

brian-1927(at)lloyd.com
Guest

Posted: Mon Oct 15, 2007 2:32 pm Post subject: pneumatic cancer

On Oct 15, 2007, at 2:53 PM, Jon Boede wrote:



 	  Quote: 	
		   Alas, my problem is not so subtle.  When I turn the main air valve  

 on, my front flap valve and my back gear handle hiss noticably.  


	


Time for a rebuild.



 	  Quote: 	
		   Oh well, as Brian points out, I'm embarassingly past all  

 disassemble-and-clean intervals on my pneumatic system.


	


You are not alone.



 	  Quote: 	
		  

 Do I really want to fix things up with linseed oil?  Anybody have a  

 better suggestion that will be kind to all the seals in the system?


	


There are probably better ways to rustproof the inside of your air  

tank(s) than linseed oil but that is what the Chinese use and it does  

work. I suspect some kind of epoxy coating would be better but how  

would you get it out again so that you could ensure you don't have  

corrosion under the coating?



--

Brian Lloyd                         3191 Western Drive

brian HYPHEN 1927 AT lloyd DOT com    Cameron Park, CA 95682

+1.916.367.2131 (voice)             +1.270.912.0788 (fax)



I fly because it releases my mind from the tyranny of petty things . . .

— Antoine de Saint-Exupéry



PGP key ID:          12095C52A32A1B6C

PGP key fingerprint: 3B1D BA11 4913 3254 B6E0  CC09 1209 5C52 A32A 1B6C

dsavarese(at)elmore.rr.co
Guest

Posted: Mon Oct 15, 2007 2:52 pm Post subject: pneumatic cancer

A 50-50 mixture of glycerin and alcohol is what is recommended.

Dennis



---

brian-1927(at)lloyd.com
Guest

Posted: Mon Oct 15, 2007 3:14 pm Post subject: pneumatic cancer

On Oct 15, 2007, at 3:51 PM, A. Dennis Savarese wrote:



 	  Quote: 	
		   

 <dsavarese(at)elmore.rr.com>



 A 50-50 mixture of glycerin and alcohol is what is recommended.


	


Uh, for detecting leaks or for corrosion-inhibiting the air tank? I  

am pretty sure you are talking about corrosion-inhibiting gunk but  

there were two topics in there and you could very well know something  

that I don't.

--

Brian Lloyd                         3191 Western Drive

brian HYPHEN 1927 AT lloyd DOT com    Cameron Park, CA 95682

+1.916.367.2131 (voice)             +1.270.912.0788 (fax)



I fly because it releases my mind from the tyranny of petty things . . .

— Antoine de Saint-Exupéry



PGP key ID:          12095C52A32A1B6C

PGP key fingerprint: 3B1D BA11 4913 3254 B6E0  CC09 1209 5C52 A32A 1B6C

rvfltd(at)televar.com
Guest

Posted: Mon Oct 15, 2007 3:19 pm Post subject: pneumatic cancer

Alas, my problem is not so subtle.  When I turn the main air valve  on, 

my front flap valve and my back gear handle hiss noticeably.  



Jon, In a "normal" situation if BOTH the front and the rear flap valves 

were leaking I would strongly advise rebuilding / changing out the flap 

actuator.  But since you have dealt us the WD-40 wild card all bets are off.



Always Yakin,

Doug

rvfltd(at)televar.com
Guest

Posted: Mon Oct 15, 2007 3:31 pm Post subject: pneumatic cancer

Guys,

Glycerin is one of the items used in the preservation of flowers, I buy 

it in truckload quantities in 55 gallon drums (USP grade), so if anyone 

wants any just let me know.  Heck, I even have a drum of Kosher glycerin 

which might be preferred by those of you who feel that it is important 

to have your air line lubricant blessed by a higher power than just your 

A&P.   I use it....I need all the help I can get! ;o)

Always Yakin,

Doug



A. Dennis Savarese wrote:



[quote] 

 <dsavarese(at)elmore.rr.com>



 A 50-50 mixture of glycerin and alcohol is what is recommended.

 Dennis



 ---

rvfltd(at)televar.com
Guest

Posted: Mon Oct 15, 2007 3:33 pm Post subject: pneumatic cancer

Mark,

 I have no info on what effect Freon might  have on the components in our systems.  My hunch is none, but let's try it on yours first OK ;O)

 

 Always dubious,

 Doug

 

 Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E wrote:

 [quote]   [quote]--> Yak-List message posted by: "Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E" <mark.bitterlich(at)navy.mil> (mark.bitterlich(at)navy.mil)  Doug, on second thought... What would prevent us from pumping Freon into our systems, ... Pure Freon that is, not any that has had compressor oil already added?  Isn't Freon in that form a clean gas?  If it is, then Freon Detectors are all over the place.  Just wondering.   I have used the Ultrasonic deals... And they work well... But the sniff detectors do work better.  Either one needs a nice hanger with the door closed.    Mark    --

brian-1927(at)lloyd.com
Guest

Posted: Mon Oct 15, 2007 4:07 pm Post subject: pneumatic cancer

On Oct 15, 2007, at 4:27 PM, Doug Sapp wrote:



 	  Quote: 	
		   



 Guys,

 Glycerin is one of the items used in the preservation of flowers, I  

 buy it in truckload quantities in 55 gallon drums (USP grade), so  

 if anyone wants any just let me know.  Heck, I even have a drum of  

 Kosher glycerin which might be preferred by those of you who feel  

 that it is important to have your air line lubricant blessed by a  

 higher power than just your A&P.   I use it....I need all the help  

 I can get! ;o)


	


Wow! That's pretty slick!



--

Brian Lloyd                         3191 Western Drive

brian HYPHEN 1927 AT lloyd DOT com    Cameron Park, CA 95682

+1.916.367.2131 (voice)             +1.270.912.0788 (fax)



I fly because it releases my mind from the tyranny of petty things . . .

— Antoine de Saint-Exupéry



PGP key ID:          12095C52A32A1B6C

PGP key fingerprint: 3B1D BA11 4913 3254 B6E0  CC09 1209 5C52 A32A 1B6C

brian-1927(at)lloyd.com
Guest

Posted: Mon Oct 15, 2007 4:07 pm Post subject: pneumatic cancer

On Oct 15, 2007, at 4:31 PM, Doug Sapp wrote:



 	  Quote: 	
		   Mark,

 I have no info on what effect Freon might  have on the components  

 in our systems.  My hunch is none, but let's try it on yours first  

 OK ;O)


	


Freon won't have any effect on the pneumatic system components. Freon  

is amazingly non-reactive and will not interact with anything in the  

pneumatic system. Once those halogen atoms bond to the carbon atoms  

they just don't want to let go for anything.



Someone already made the point about not using freon with compressor  

oil in it. If you follow that advice you are good to go.



--

Brian Lloyd                         3191 Western Drive

brian HYPHEN 1927 AT lloyd DOT com    Cameron Park, CA 95682

+1.916.367.2131 (voice)             +1.270.912.0788 (fax)



I fly because it releases my mind from the tyranny of petty things . . .

— Antoine de Saint-Exupéry



PGP key ID:          12095C52A32A1B6C

PGP key fingerprint: 3B1D BA11 4913 3254 B6E0  CC09 1209 5C52 A32A 1B6C

wlannon(at)persona.ca
Guest

Posted: Mon Oct 15, 2007 4:12 pm Post subject: pneumatic cancer

Doug;



If you use Kosher glycerine for the first 50%, what do you use for the last 

50? Jack Daniels or Glenlivet??



Cheers;

Walt

---

dsavarese(at)elmore.rr.co
Guest

Posted: Mon Oct 15, 2007 6:43 pm Post subject: pneumatic cancer

You're right. Not for detecting leaks.  For preventing rust and corrosion.

Dennis

---

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