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Air Leak Advice
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mark.bitterlich(at)navy.m
Guest

Posted: Wed Apr 22, 2015 8:48 am Post subject: Air Leak Advice

Dave wanted me to emphasize the requirement of a pressure regulator when back feeding lines to the compressor and he is absolutely correct.  Applying unregulated air from a Scuba tank delivering 2000 PSI (or more) of air to these lines will likely cause damage and could indeed be quite dangerous.  So "Word to the Wise" be careful!  



Point of fact:  Never exceed maximum recommended operating pressure to any system.  For the YAK's and Sukes (not sure of CJ's) the max is 50 atmos, which equates to 734 PSI or so.  

--

wlannon(at)shaw.ca
Guest

Posted: Wed Apr 22, 2015 9:22 am Post subject: Air Leak Advice

Hi Mark;



CJ is the same.



Walt

--

AcroGimp

Joined: 11 Jun 2013
Posts: 45
Location: San Diego, CA USA

Posted: Wed Apr 22, 2015 9:29 am Post subject: Re: Air Leak Advice

 	  mark.bitterlich(at)navy.m wrote: 	
		  Dave wanted me to emphasize the requirement of a pressure regulator when back feeding lines to the compressor and he is absolutely correct.  Applying unregulated air from a Scuba tank delivering 2000 PSI (or more) of air to these lines will likely cause damage and could indeed be quite dangerous.  So "Word to the Wise" be careful!  



Point of fact:  Never exceed maximum recommended operating pressure to any system.  For the YAK's and Sukes (not sure of CJ's) the max is 50 atmos, which equates to 734 PSI or so.  

-- 	
Understood, I found a welding regulator that has PSI and ATM on the gage face and I would never apply unregulated 2000-3000 PSI tank air to lines that operate at around 700.  Issue now is fabbing a line that connects to the regulated output and then can connect to the air lines on the Yak.  Once I figure it out I might post up some photos and a drawing and parts list since I am hoping to be able to cobble something together from COTS parts.



'Gimp

_________________
Owner/Pilot N6209F 1987 Yak-52
COMM/ASEL/IFR/HP-Complex/TW

LawnDart

Joined: 05 Jun 2006
Posts: 64

Posted: Wed Apr 22, 2015 10:52 am Post subject: Re: Air Leak Advice

Yes, your scuba tank should have a regulator and proper PSI hosing, blah, blah.  You should also wear safety glasses and tuck in your tie if you used the suggested lathe.

mark.bitterlich(at)navy.m
Guest

Posted: Wed Apr 22, 2015 11:19 am Post subject: Air Leak Advice

In my opinion, belittling efforts to inject some safety into the discussion at hand makes no sense at all.   

--

cd001633(at)mindspring.co
Guest

Posted: Wed Apr 22, 2015 12:02 pm Post subject: Air Leak Advice

Mark,



You're absolutely right!   That is very much my opinion too!



Sam Sax

--

pfstelwagon(at)earthlink.
Guest

Posted: Wed Apr 22, 2015 1:20 pm Post subject: Air Leak Advice

Don't use any of those items then we won't have to listen to  you.



Sent from my iPhone



 	  Quote: 	
		   On Apr 22, 2015, at 11:52, "LawnDart" <propwash(at)gmail.com> wrote:

 

 

 

 Yes, your scuba tank should have a regulator and proper PSI hosing, blah, blah.  You should also wear safety glasses and tuck in your tie if you used the suggested lathe.

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=441133#441133

markdavis(at)wbsnet.org
Guest

Posted: Wed Apr 22, 2015 1:24 pm Post subject: Air Leak Advice

Crack a 4,400 psi scuba tank full open and let us know how it turns out.

Pressure and volume are two different animals if you're feeding in high

pressure air into the system faster than the pressure relief valve can dump

it.  Just because your cockpit gauge doesn't show an over pressure state

doesn't mean you're not exceeding the pressure limits of the system

somewhere between the fill port and the regulator due to restrictions in

flow.  A regulator on a tank dodges that bullet.  Personally, when a topic

goes beyond my level of interest, I just don't read it.  Other times I read

it to catch something new I didn't know or some of the vast amount of things

I've learned and forgotten.  Thanks to all who are regular contributors who

answer the same questions over and over and over and over.......  Some of

them were mine.  : )



Mark Davis

N44YK

--

wlannon(at)shaw.ca
Guest

Posted: Wed Apr 22, 2015 5:27 pm Post subject: Air Leak Advice

And mine.  Right on.



Walt



--

AcroGimp

Joined: 11 Jun 2013
Posts: 45
Location: San Diego, CA USA

Posted: Thu Apr 23, 2015 7:50 am Post subject: Re: Air Leak Advice

Failed the glove check, looks like compressor shear shaft.  Mechanic's spare compressor is here so I checked on it to see what it should look like, nothing on the plane.



So next question is just how bad is removing the compressor, and other than the occasional kickback, what other causes for shearing the shaft?



Thanks in advance.



'Gimp

_________________
Owner/Pilot N6209F 1987 Yak-52
COMM/ASEL/IFR/HP-Complex/TW

mark.bitterlich(at)navy.m
Guest

Posted: Thu Apr 23, 2015 8:41 am Post subject: Air Leak Advice

Age, gunk getting into compressor, compressor internal part failure, and just simply wearing out, etc.  Which is why I asked you how many hours were on it.   



Removing the compressor is difficult and patience is required.  You are going to need the special tool that comes in the Russian tool kit.  Otherwise you are going to need to make special tools.  



Jill at M14P sells a special kit  that includes some special wrenches.  I want to say she reduces the nut size from 14mm to 10mm, but don't quote me on that .. ask her.   Regardless, you still have to take the original one off.  I assume you are going to replace the coupler and also put on a new or rebuild compressor.  Jill also has the correct gaskets needed, and be careful putting them on, as they are easy to get backwards which will block an oil passage.    Simply put, it is not a lot of fun but do-able ... and it helps to have someone with long thin fingers!  



--

AcroGimp

Joined: 11 Jun 2013
Posts: 45
Location: San Diego, CA USA

Posted: Thu Apr 23, 2015 9:26 am Post subject: Re: Air Leak Advice

Checked the logs and compressor has 41 hrs of operation - installed new last August.



I have had a reverse rotation/dieseling event I think twice in about 15-16 flights, both times only a couple of blades but still it did happen.  Last occurrence was flight prior to flight where everything pumped up correctly, so 3 flights ago. 



When I overhauled the snot valve side check valve it was very dirty, the fill side was clean, so I am planning to overhaul PRV and snot valve during this down cycle, as well as putting a serious clean on the little piston valve in the coupler at the bottom of the compressor.



Until I remove the old compressor I won't know if it is a shear shaft issue or something else but I will absolutely check the compressor gasket for the oil passage.  Would you guys go back to the mech for compensation if the gasket was installed incorrectly (asking, first airplane and all)?



Thanks for the support and info...



'Gimp

_________________
Owner/Pilot N6209F 1987 Yak-52
COMM/ASEL/IFR/HP-Complex/TW

rocknpilot(at)hotmail.com
Guest

Posted: Thu Apr 23, 2015 10:12 am Post subject: Air Leak Advice

Nuts are 11 mm. Trust me...I've birthed this baby 5 times. And you are correct, probably impossible w/o the curved / flexing 11 mm Russian wrench. The lock washers are also very tough to align before even approaching w/ a nut since there is extremely little work space - and (looking at the compressor) the nut at about the 10:00 position in the most challenging. I used a kind of "paste" to stick the hardware to my fingers because often you can only get one (1) finger into the work space where the stud is. Once the nuts are threaded, torquing is a cinch! Save yourself some time and invent some new curse words now. Not fun, but if you do it enough it can get to be a less painful routine...



Rico Jaeger

915 S. 11th Ave.                  

Wausau, WI. 54401     

715.529.7426                    

                                                                    //

1966 Cessna 150F                            ^/---//-X

N8558G                                                  //Hangar #35 / AUW

                                                  //               

1992 Yakovlev Yak 52    ^/---//-X

N21YK                                   //

Hangar #21 / AUW

                                          





[quote] From: mark.bitterlich(at)navy.mil

 To: yak-list(at)matronics.com

 Subject: RE: Re: Air Leak Advice

 Date: Thu, 23 Apr 2015 16:40:20 +0000

 

 --> Yak-List message posted by: "Bitterlich, Mark G CIV NAVAIR, WD" <mark.bitterlich(at)navy.mil>

 

 Age, gunk getting into compressor, compressor internal part failure, and just simply wearing out, etc.  Which is why I asked you how many hours were on it.   

 

 Removing the compressor is difficult and patience is required.  You are going to need the special tool that comes in the Russian tool kit.  Otherwise you are going to need to make special tools.  

 

 Jill at M14P sells a special kit  that includes some special wrenches.  I want to say she reduces the nut size from 14mm to 10mm, but don't quote me on that .. ask her.   Regardless, you still have to take the original one off.  I assume you are going to replace the coupler and also put on a new or rebuild compressor.  Jill also has the correct gaskets needed, and be careful putting them on, as they are easy to get backwards which will block an oil passage.    Simply put, it is not a lot of fun but do-able ... and it helps to have someone with long thin fingers!  

 

 --

AcroGimp

Joined: 11 Jun 2013
Posts: 45
Location: San Diego, CA USA

Posted: Thu Apr 23, 2015 12:27 pm Post subject: Re: Air Leak Advice

Another question, is there supposed to be a cooling horn pointed at the compressor?  Current install has a cooling tube from the front of the engine side that just ends facing aft near the motor mount and could have had something on it direct cooling air at the compressor but nothing I can see for this right now.



Just curious...



'Gimp

_________________
Owner/Pilot N6209F 1987 Yak-52
COMM/ASEL/IFR/HP-Complex/TW

mark.bitterlich(at)navy.m
Guest

Posted: Thu Apr 23, 2015 1:19 pm Post subject: Air Leak Advice

Roger on 11 mm.  I am pretty sure Jill's "better way of doing it" uses 10 mm to allow for a little more space.   Not saying that is the best way to go, just saying I bought it to take a look and see.



And yes Gimp, there is supposed to be an air tube with a fitting on the end that provides cooling air around the compressor.   Sounds like you might be missing the fitting.  I forgot to mention "HEAT" as one of the things that can make a compressor fail earlier than normal.  



Good luck and thanks Rico.



Mark



________________________________

From: owner-yak-list-server(at)matronics.com [owner-yak-list-server(at)matronics.com] on behalf of Rico Jaeger [rocknpilot(at)hotmail.com]

Sent: Thursday, April 23, 2015 2:11 PM

To: yak-list(at)matronics.com

Subject: RE: Re: Air Leak Advice



Nuts are 11 mm. Trust me...I've birthed this baby 5 times. And you are correct, probably impossible w/o the curved / flexing 11 mm Russian wrench. The lock washers are also very tough to align before even approaching w/ a nut since there is extremely little work space - and (looking at the compressor) the nut at about the 10:00 position in the most challenging. I used a kind of "paste" to stick the hardware to my fingers because often you can only get one (1) finger into the work space where the stud is. Once the nuts are threaded, torquing is a cinch! Save yourself some time and invent some new curse words now. Not fun, but if you do it enough it can get to be a less painful routine...



Rico Jaeger

915 S. 11th Ave.

Wausau, WI. 54401

715.529.7426

                                                                    //

1966 Cessna 150F                            ^/---//-X

N8558G                                                  //

Hangar #35 / AUW

                                                  //

1992 Yakovlev Yak 52    ^/---//-X

N21YK                                   //

Hangar #21 / AUW





[quote] From: mark.bitterlich(at)navy.mil

 To: yak-list(at)matronics.com

 Subject: RE: Re: Air Leak Advice

 Date: Thu, 23 Apr 2015 16:40:20 +0000



 



 Age, gunk getting into compressor, compressor internal part failure, and just simply wearing out, etc. Which is why I asked you how many hours were on it.



 Removing the compressor is difficult and patience is required. You are going to need the special tool that comes in the Russian tool kit. Otherwise you are going to need to make special tools.



 Jill at M14P sells a special kit that includes some special wrenches. I want to say she reduces the nut size from 14mm to 10mm, but don't quote me on that .. ask her. Regardless, you still have to take the original one off. I assume you are going to replace the coupler and also put on a new or rebuild compressor. Jill also has the correct gaskets needed, and be careful putting them on, as they are easy to get backwards which will block an oil passage. Simply put, it is not a lot of fun but do-able ... and it helps to have someone with long thin fingers!



 --

pfstelwagon(at)earthlink.
Guest

Posted: Thu Apr 23, 2015 1:22 pm Post subject: Air Leak Advice

Byron Fox on this list has composite cooling horns.



Frank

---

AcroGimp

Joined: 11 Jun 2013
Posts: 45
Location: San Diego, CA USA

Posted: Thu Apr 23, 2015 1:50 pm Post subject: Re: Air Leak Advice

 	  pfstelwagon(at)earthlink. wrote: 	
		  Byron Fox on this list has composite cooling horns.



Frank

--- 	
Thanks Frank, I expect to see Blitz tomorrow at Porterville and will ask when I see him.



Thanks



'Gimp

_________________
Owner/Pilot N6209F 1987 Yak-52
COMM/ASEL/IFR/HP-Complex/TW

Viperdoc

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

Posted: Thu Apr 23, 2015 5:37 pm Post subject: Air Leak Advice

The A/C probably had more kick backed before you got it. It will sheer also it the compressor is working against a high pressure to protect the compressor accessory drive gears. 

Doc



Sent from my iPad



 	  Quote: 	
		   On Apr 23, 2015, at 10:50 AM, AcroGimp <jlknolla(at)aol.com> wrote:

 

 

 

 Failed the glove check, looks like compressor shear shaft.  Mechanic's spare compressor is here so I checked on it to see what it should look like, nothing on the plane.

 

 So next question is just how bad is removing the compressor, and other than the occasional kickback, what other causes for shearing the shaft?

 

 Thanks in advance.

 

 'Gimp

 

 --------

 Owner/Pilot N6209F 1987 Yak-52

 COMM/ASEL/IFR/HP-Complex/TW

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=441175#441175

_________________
Viperdoc

Viperdoc

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

Posted: Thu Apr 23, 2015 6:24 pm Post subject: Air Leak Advice

Gimp,

Which gasket are you referring to? The aluminum crush washer on the check valve or the gasket on the accessory drive case. It is real tough to get the gasket forming the oil seal on base of the compressor as it mates to the accessory case wrong. I guess if you really worked hard at it one could though. 

Doc



Sent from my iPad



 	  Quote: 	
		   On Apr 23, 2015, at 12:27 PM, AcroGimp <jlknolla(at)aol.com> wrote:

 

 

 

 Checked the logs and compressor has 41 hrs of operation.

 

 I have had a reverse rotation/dieseling event I think twice in about 15-16 flights, both times only a couple of blades but still it did happen.  Last occurrence was flight prior to flight where everything pumped up correctly, so 3 flights ago. 

 

 When I overhauled the snot valve side check valve it was very dirty, the fill side was clean, so I am planning to overhaul PRV and snot valve during this down cycle, as well as putting a serious clean on the little piston valve in the coupler at the bottom of the compressor.

 

 Until I remove the old compressor I won't know if it is a shear shaft issue or something else but I will absolutely check the compressor gasket for the oil passage.  Would you guys go back to the mech for compensation if the gasket was installed incorrectly (asking, first airplane and all)?

 

 Thanks for the support and info...

 

 'Gimp

 

 --------

 Owner/Pilot N6209F 1987 Yak-52

 COMM/ASEL/IFR/HP-Complex/TW

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=441181#441181

_________________
Viperdoc

Viperdoc

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

Posted: Thu Apr 23, 2015 6:26 pm Post subject: Air Leak Advice

Yes, for the 52 but not the 50.

Doc



Sent from my iPad



 	  Quote: 	
		   On Apr 23, 2015, at 3:27 PM, AcroGimp <jlknolla(at)aol.com> wrote:

 

 

 

 Another question, is there supposed to be a cooling horn pointed at the compressor?  Current install has a cooling tube from the front of the engine side that just ends facing aft near the motor mount and could have had something on it direct cooling air at the compressor but nothing I can see for this right now.

 

 Just curious...

 

 'Gimp

 

 --------

 Owner/Pilot N6209F 1987 Yak-52

 COMM/ASEL/IFR/HP-Complex/TW

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=441186#441186

_________________
Viperdoc

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