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[GMCnet] Leveler leak down [message #363389] Tue, 13 April 2021 10:54 Go to next message
Hanson Email is currently offline  Hanson Email
Messages: 110
Registered: March 2020
Karma: -1
Senior Member
I have overhauled the rotary valves and there is no leak down at that end.
And my tank pressure drops rapidly with the valves in hold. So with the
valves shut off, and the bags shut off, and the one way valve new and
working so it is not going out the AC, the tank pressure is going out the
levelers or at least to the line to the levelers. There is also a chance I
have a leak in that line but I don't think so.

That leads me to the leveler itself ??? I'm wondering do I take the arm
loose and 'exercise' it? Take it off and clean it up? Anyone take that thing
apart?

TFHIA.

Dean Hanson

75 Avion with mono bag and shut offs.

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[GMCnet] Re: Leveler leak down [message #363390 is a reply to message #363389] Tue, 13 April 2021 12:38 Go to previous messageGo to next message
Keith V is currently offline  Keith V   United States
Messages: 2337
Registered: March 2008
Location: Mounds View,MN
Karma: 0
Senior Member
Maybe you can free up the valve, worth a shot. I would think a soap test would prove that therory.
Note also that some air lines are very brittle, you could have a crack in one
________________________________
From: Hanson Email
Sent: Tuesday, April 13, 2021 10:54:29 AM
To: gmclist@list.gmcnet.org
Subject: [GMCnet] Leveler leak down

I have overhauled the rotary valves and there is no leak down at that end.
And my tank pressure drops rapidly with the valves in hold. So with the
valves shut off, and the bags shut off, and the one way valve new and
working so it is not going out the AC, the tank pressure is going out the
levelers or at least to the line to the levelers. There is also a chance I
have a leak in that line but I don't think so.

That leads me to the leveler itself ??? I'm wondering do I take the arm
loose and 'exercise' it? Take it off and clean it up? Anyone take that thing
apart?

TFHIA.

Dean Hanson

75 Avion with mono bag and shut offs.

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Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com
[GMCnet] Re: Leveler leak down [message #363392 is a reply to message #363389] Tue, 13 April 2021 13:20 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
Senior Member
Dean,
We have found that the original Rotary Valves tend to develop a
crevis which will leak.
Lot of people have purchased the Brass Valve kit and love it.

On Tue, Apr 13, 2021 at 8:54 AM Hanson Email wrote:

> I have overhauled the rotary valves and there is no leak down at that end.
> And my tank pressure drops rapidly with the valves in hold. So with the
> valves shut off, and the bags shut off, and the one way valve new and
> working so it is not going out the AC, the tank pressure is going out the
> levelers or at least to the line to the levelers. There is also a chance I
> have a leak in that line but I don't think so.
>
> That leads me to the leveler itself ??? I'm wondering do I take the arm
> loose and 'exercise' it? Take it off and clean it up? Anyone take that
> thing
> apart?
>
> TFHIA.
>
> Dean Hanson
>
> 75 Avion with mono bag and shut offs.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>


--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.gmcrvparts.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
Re: [GMCnet] Leveler leak down [message #363401 is a reply to message #363389] Tue, 13 April 2021 17:10 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   Canada
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
Senior Member
Dean,

I had a system that remained leak free for a long time. I found two issue and only have a cure for one.

First and fixed was the body gasket of the rotary valves is cork. In the GM labeled rebuild kits that came in my coach, they were cork, but with an adhesive coating on one side only. After an extended time assembled (several years) they developed a leak at the body joint. This was a level of leak that we in the sealing biz called champagne bubbles. These can be in range of CCs/hr. (Not a lot, but a leak over days/weeks). The adhesive coated cork just sealed one face so the other could leak and also guaranteed that the valve could not be disassembled without damaging these gaskets. This level of leakage is a known issue with composite cork/rubber materials.

When I got kits from Applied, those contained similar gaskets without the coating. When these started to leak (again with the tiny bubbles), I coated the gaskets with Loctite 565 or 567 (one of those), and the bubbles stopped. Months later, they still don't blow bubbles. Small problem, that stuff is expensive.

I now have another problem. I know where it is. The ride-height control valves both leak when at the set point. I don't know what part leaks, but they can be shown to be venting while stationary. You know that they have system air pressure on them at all times - right? The thoughtful PO left me with a non-identical replacement, but only one. I have not even bothered to pursue installing it. Dave Lenzi used to rebuild them, but he came up short on some essential component a while back and has better things to do.

So, when I am going to go someplace with the coach, I either set the switch to ACC before I start the walk around or drag a shop air line out to the tank.
Yes, it is a little annoying, but I have a long list of annoying things that I let go by.

Matt


Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
Re: [GMCnet] Leveler leak down [message #363413 is a reply to message #363389] Wed, 14 April 2021 02:33 Go to previous messageGo to next message
Ken Burton is currently offline  Ken Burton   United States
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
Senior Member
Those leveling valves that Dave use to rebuild are available new and made by a company out of Ohio. I got one rebuilt from Dave and one new one from Jim K. Both have lasted equally well. Call Jim K. at Applied GMC. He has them, or at least use to have them.

Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
[GMCnet] Re: Leveler leak down [message #363435 is a reply to message #363390] Thu, 15 April 2021 10:59 Go to previous message
Hanson Email is currently offline  Hanson Email
Messages: 110
Registered: March 2020
Karma: -1
Senior Member
Matt Said:

I now have another problem. I know where it is. The ride-height control
valves both leak when at the set point. I don't know what part leaks, but
they can be shown to be venting while stationary. You know that they have
system air pressure on them at all times - right? The thoughtful PO left me
with a non-identical replacement, but only one. I have not even bothered to
pursue installing it. Dave Lenzi used to rebuild them, but he came up

short on some essential component a while back and has better things to do.




Dean responds:

I believe this is my problem and yes, I know they have air pressure at all
times. And it drains my tank within 2 to 3 minutes. My go around is to use
my Ryobi battery powered AC to set my height with my shutoff valves closed.
Works like a champ. Never use the rotary valves up front, always set to
hold.

Does anyone have "working" ride-height control valves available?

Dean Hanson

75 Avion

73 Painted Desert.



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