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Very slow air leak...how to find it

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yakxx21

Joined: 10 Jun 2012
Posts: 22

Posted: Sat Nov 08, 2014 2:01 pm Post subject: Very slow air leak...how to find it

Can  anybody tell me what might be the procedure to find a very small air leak from the main system...it goes down from 6 to 5 over 48 hours...I can't hear any leaks and have sprayed liquid on most junctions to look for bubbled but acnt see any...is there a set procedure to work along ...not sure where to start really



YAK 50 by the way...

Viperdoc

Joined: 19 Apr 2014
Posts: 484
Location: 08A

Posted: Sat Nov 08, 2014 5:04 pm Post subject: Very slow air leak...how to find it

When were your check valves on the fire wall changed? 

Doc



Sent from my iPad



 	  Quote: 	
		   On Nov 8, 2014, at 4:01 PM, yakxx21 <ken(at)aeroalgarve.com> wrote:

 

 

 

 Can  anybody tell me what might be the procedure to find a very small air leak from the main system...it goes down from 6 to 5 over 48 hours...I can't hear any leaks and have sprayed liquid on most junctions to look for bubbled but acnt see any...is there a set procedure to work along ...not sure where to start really

 

 YAK 50 by the way...

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=433173#433173

_________________
Viperdoc

yakxx21

Joined: 10 Jun 2012
Posts: 22

Posted: Sun Nov 09, 2014 12:48 am Post subject: Re: Very slow air leak...how to find it

Well....I have only changed the top ( pressure release) valve....



Are there more and where are they ??  I see a straight pipe going down and maybe there are two either side of the cluster. ....is that correct and should I change those as well....?



Thanks for any info

ronpenrose

Joined: 16 Jul 2014
Posts: 15
Location: Kansas City Metro (KLXT)

Posted: Mon Nov 10, 2014 5:54 am Post subject: Re: Very slow air leak...how to find it

I have same problem since temperature here has dropped below around nid 40's.

_________________
Ron Penrose
YAK-52 N352BW

yakxx21

Joined: 10 Jun 2012
Posts: 22

Posted: Mon Nov 10, 2014 7:06 am Post subject: Re: Very slow air leak...how to find it

why would temperature effect it ?....looking at the diagram it seems it can only go back to the charging point (which its not)  or leak around the tank itself (cant see any soapy leaks) or lose something through the check valve going to engine driven compressor and Im not sure how to check that



also im not sure if the SNOT valve would affect it if left open----or if not sealing correctly....



finally I suppose I could change the pressure release rubber again....



frustrating

ronpenrose

Joined: 16 Jul 2014
Posts: 15
Location: Kansas City Metro (KLXT)

Posted: Mon Nov 10, 2014 7:21 am Post subject: Re: Very slow air leak...how to find it

Cold temperatures can cause a fitting to leak if conditions are right.  Old rubber seal will get hard or a fitting may leak if it has loosened a bit.  Even though the fittings are safetyed and should not loosen, I found some on my plan where the safety had not been done correctly and had some slack and loosened an eighth of a turn which was enough to cause leakage.  I am going to check those fittings from the tank to the blowoff valve and Tee on firewall.  I do not believe the snot valve and plumbing is a culprit since tank air pressure an plumbing is independent of that area (I think!).

_________________
Ron Penrose
YAK-52 N352BW

dsavarese0812(at)bellsout
Guest

Posted: Mon Nov 10, 2014 7:38 am Post subject: Very slow air leak...how to find it

Try this:

- Fill the main and emergency air tanks

- Make sure the main air is off

- Write down the pressure in both tanks

- Squeeze the brakes until you can't hear any "swish" when you release 

the brakes.

- Let the system sit overnight or at least 4 hours or so.

- Come back to the next morning and compare the pressure in both tanks 

with what you wrote down yesterday. (Note: as the air in the tanks cool 

down, the pressure will drop slightly.  So take that into account)

- Now squeeze and release the brake handle again. If you hear any 

"swish" at all when you release the brake handle, one or possibly both 

of the air valves is leaking, even when shut off.  Verify which take 

side (main or emergency) has dropped further than the other.  That 

should be the air valve that is leaking.



The snot bottle is isolated from the main air tank by the check valve.  

If the check valves are good, no air can come back to the check valve 

from the main air bottle.  If you leave the snot bottle open and the 

check valve is leaking, there will be air coming out of the snot bottle 

relief end.  Wet your finger and open the snot bottle or put the tube on 

the snot bottle in a container with water and watch for bubbles. If you 

can feel the leak or see bubbles, the check valve is leaking.



A. Dennis Savarese

334-546-8182 (mobile)

www.yak-52.com

Skype - Yakguy1



On 11/10/2014 9:06 AM, yakxx21 wrote:

 	  Quote: 	
		   



 why would temperature effect it ?....looking at the diagram it seems it can only go back to the charging point (which its not)  or leak around the tank itself (cant see any soapy leaks) or lose something through the check valve going to engine driven compressor and Im not sure how to check that



 also im not sure if the SNOT valve would affect it if left open----or if not sealing correctly....



 finally I suppose I could change the pressure release rubber again....



 frustrating





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=433323#433323

dsavarese0812(at)bellsout
Guest

Posted: Mon Nov 10, 2014 7:40 am Post subject: Very slow air leak...how to find it

Over tightening         the B-nuts also may cause the flare on the end of the tubing to crack/split.  Finding these are a real                             pain.                  The tubing in the Yak's are                 very brittle.   So if you remove a                   B-nut for                       any reason, don't over tighten it                   when reinstalling.

                     Dennis  

        	  Quote: 	
		  A. Dennis Savarese

334-546-8182 (mobile)

www.yak-52.com

Skype - Yakguy1 	
       On 11/10/2014 9:21 AM, ronpenrose wrote:

     

     [quote]        	  Quote: 	
		  --> Yak-List message posted by: "ronpenrose" <rpenrose(at)kc.rr.com> (rpenrose(at)kc.rr.com)



Cold temperatures can cause a fitting to leak if conditions are right.  Old rubber seal will get hard or a fitting may leak if it has loosened a bit.  Even though the fittings are safetyed and should not loosen, I found some on my plan where the safety had not been done correctly and had some slack and loosened an eighth of a turn which was enough to cause leakage.  I am going to check those fittings from the tank to the blowoff valve and Tee on firewall.  I do not believe the snot valve and plumbing is a culprit since tank air pressure an plumbing is independent of that area (I think!).



--------

Ron Penrose

YAK-52 N352BW





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=433325#433325



	
     [b]

mark.bitterlich(at)navy.m
Guest

Posted: Mon Nov 10, 2014 7:45 am Post subject: Very slow air leak...how to find it

After a day or two of not flying... open the snot valve.   If you hear a loud hiss of air, you more than likely have air leaking through the check valves and back into the compressor line.



Next, use external air to fill both tanks.   Then (one at a time) remove the lines coming into the check valve assembly (described in a previous email) that are coming from the engine compressor to the check valve assembly.   If you want, you can take a balloon and put it over the fitting of the check valve you just removed the line from coming from the engine, to snot valve, to check valve assembly.   Tie it on there tight and leave it for a few hours and see if it blows up.



If nothing happens, you can go back to the external fill port and put soapy water there... look for air coming out the external fill port.  This checks THAT check valve.   You could also take off the fitting going to the external fill port at the check valve assembly and use the balloon trick again.



Realize if you have air coming out of EITHER of these, you also will a check valve bad going to one of the two AIR tanks.



If you decide you have a check valve leaking, send all four to George Coy and his son, and they will rebuild them for you.

That's a little bit of a start to get you  going anyway.



Mark

--

dsavarese0812(at)bellsout
Guest

Posted: Mon Nov 10, 2014 7:52 am Post subject: Very slow air leak...how to find it

FWIW, the CJ6 check valves available from Doug Sapp are pretty much           identical to the check valves on the 50.

        	  Quote: 	
		  A. Dennis Savarese

334-546-8182 (mobile)

www.yak-52.com

Skype - Yakguy1 	
       On 11/10/2014 9:45 AM, Bitterlich, Mark G CIV NAVAIR, WD wrote:

     

     [quote]       [quote]--> Yak-List message posted by: "Bitterlich, Mark G CIV NAVAIR, WD" <mark.bitterlich(at)navy.mil> (mark.bitterlich(at)navy.mil)  After a day or two of not flying... open the snot valve.   If you hear a loud hiss of air, you more than likely have air leaking through the check valves and back into the compressor line.  Next, use external air to fill both tanks.   Then (one at a time) remove the lines coming into the check valve assembly (described in a previous email) that are coming from the engine compressor to the check valve assembly.   If you want, you can take a balloon and put it over the fitting of the check valve you just removed the line from coming from the engine, to snot valve, to check valve assembly.   Tie it on there tight and leave it for a few hours and see if it blows up.  If nothing happens, you can go back to the external fill port and put soapy water there... look for air coming out the external fill port.  This checks THAT check valve.   You could also take off the fitting going to the external fill port at the check valve assembly and use the balloon trick again.  Realize if you have air coming out of EITHER of these, you also will a check valve bad going to one of the two AIR tanks.  If you decide you have a check valve leaking, send all four to George Coy and his son, and they will rebuild them for you.   That's a little bit of a start to get you  going anyway.  Mark   --

mark.bitterlich(at)navy.m
Guest

Posted: Mon Nov 10, 2014 8:08 am Post subject: Very slow air leak...how to find it

This is news to me.   I'd love to see pictures of one!  



Realize that the 50 used two types of check valves during their construction periods.  Neither match those used on a 52.  That makes no sense to me, but it is what I have seen on four of them now.  



Mark



--

Viperdoc

Joined: 19 Apr 2014
Posts: 484
Location: 08A

Posted: Tue Nov 11, 2014 2:50 pm Post subject: Very slow air leak...how to find it

On the YAK 50, the Chinese check valves work also. Did not know about Goerge rebuilding the check valves until after I had replaced mine with brand new ones Doug Sapp.

Doc



Sent from my iPad



[quote] On Nov 10, 2014, at 9:45 AM, Bitterlich, Mark G CIV NAVAIR, WD <mark.bitterlich(at)navy.mil> wrote:

 

 

 

 After a day or two of not flying... open the snot valve.   If you hear a loud hiss of air, you more than likely have air leaking through the check valves and back into the compressor line.

 

 Next, use external air to fill both tanks.   Then (one at a time) remove the lines coming into the check valve assembly (described in a previous email) that are coming from the engine compressor to the check valve assembly.   If you want, you can take a balloon and put it over the fitting of the check valve you just removed the line from coming from the engine, to snot valve, to check valve assembly.   Tie it on there tight and leave it for a few hours and see if it blows up.

 

 If nothing happens, you can go back to the external fill port and put soapy water there... look for air coming out the external fill port.  This checks THAT check valve.   You could also take off the fitting going to the external fill port at the check valve assembly and use the balloon trick again.

 

 Realize if you have air coming out of EITHER of these, you also will a check valve bad going to one of the two AIR tanks.

 

 If you decide you have a check valve leaking, send all four to George Coy and his son, and they will rebuild them for you.

 

 

 That's a little bit of a start to get you  going anyway.

 

 Mark

 

 

 --

_________________
Viperdoc

mark.bitterlich(at)navy.m
Guest

Posted: Wed Nov 12, 2014 8:07 am Post subject: Very slow air leak...how to find it

I'd actually like to rebuild the whole arrangement with western made check valves, filter, and pop-off valve.  Saw it done on a Sukhoi, looked up the pressure relief valve and it retailed for $800.  Wow.



Mark

--

Viperdoc

Joined: 19 Apr 2014
Posts: 484
Location: 08A

Posted: Wed Nov 12, 2014 2:29 pm Post subject: Very slow air leak...how to find it

Doug's supplies are no where that expensive for the whole H.

Doc



Sent from my iPad



[quote] On Nov 12, 2014, at 10:06 AM, Bitterlich, Mark G CIV NAVAIR, WD <mark.bitterlich(at)navy.mil> wrote:

 

 

 

 I'd actually like to rebuild the whole arrangement with western made check valves, filter, and pop-off valve.  Saw it done on a Sukhoi, looked up the pressure relief valve and it retailed for $800.  Wow.

 

 Mark

 

 

 --

_________________
Viperdoc

mark.bitterlich(at)navy.m
Guest

Posted: Thu Nov 13, 2014 6:53 am Post subject: Very slow air leak...how to find it

I understand that Doc.   



However, the western made check valves and pressure relief valves are of a much higher quality make no mistake.   Having the Coy's rebuild your valves is also cheaper than purchasing them from Doug, and they do a darn fine job.   That said, all of the ones I am talking about are stainless steel, corrosion proof and will outlast most everything out there.  Just commenting that you have to pay a lot to get that kind of quality it seems.  The other PITA issue is building adapters to go to the original air lines.  



Size is also an issue.  As I mentioned, I was very surprised to see different sizes of check valves (also with different thread sizes) used in two different 50's.  The 1974 had a small set, the 1985 had a larger set, and neither was the same as what was used on the 52 which had an ever bigger size!  



Mark

--

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Viperdoc

Joined: 19 Apr 2014
Posts: 484
Location: 08A

Posted: Thu Nov 13, 2014 7:59 am Post subject: Very slow air leak...how to find it

Agree on size differences as well as SS fitting are more desirable. Would commit to them if I had not already done them.

Doc



Sent from my iPad



[quote] On Nov 13, 2014, at 8:51 AM, Bitterlich, Mark G CIV NAVAIR, WD <mark.bitterlich(at)navy.mil> wrote:

 

 I understand that Doc.   

 

 However, the western made check valves and pressure relief valves are of a much higher quality make no mistake.   Having the Coy's rebuild your valves is also cheaper than purchasing them from Doug, and they do a darn fine job.   That said, all of the ones I am talking about are stainless steel, corrosion proof and will outlast most everything out there.  Just commenting that you have to pay a lot to get that kind of quality it seems.  The other PITA issue is building adapters to go to the original air lines.  

 

 Size is also an issue.  As I mentioned, I was very surprised to see different sizes of check valves (also with different thread sizes) used in two different 50's.  The 1974 had a small set, the 1985 had a larger set, and neither was the same as what was used on the 52 which had an ever bigger size!  

 

 Mark

 

 

 --

_________________
Viperdoc

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