Home » Public Forums » GMCnet » Air suspension woes... (Something broke...)
| Air suspension woes... [message #350325] |
Mon, 25 November 2019 17:29  |
Shawn Bennear
Messages: 43
Registered: February 2007
Location: Edinburg, PA
Karma: -1
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I had the Palm Beach out for a ride and all was well... I am not sure what happened to it after I parked it, but now all of a sudden it will not build air to either bag, and in fact, it will actually dump the air even when it is set to raise on either bag. The compressor is running and apparently filling the air tank, but not sure why it isn't going where it needs to go. If you hit the switches to lower, you can hear the air hissing... Just no raise. I have looked in the compressor spot in the cabinet, but I don't see or hear any hissing in there. I have no idea where the air tank is on the Palm Beach, gonna have to hunt the service manual... I did notice that the round part on one solenoid spins, and it is the middle one for the blue hose. Don't know if that has anything to do with it or not.
My friend Dave has a 78 coach, and he has 2 compressors and I didn't see any solenoids on his...Unless I'm blind...lol
Anyone have any thoughts on where to begin? I'd appreciate it.
I may just have to figure out the measurements for a couple 4x4 posts to sit under the bogies for the winter until I figure out the mystery...
Shawn
http://www.gmcmotorhomeworld.com
1977 Palm Beach, 403 V8 w headers.
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| Re: Air suspension woes... [message #350327 is a reply to message #350325] |
Mon, 25 November 2019 17:56  |
6cuda6
Messages: 975
Registered: June 2019
Karma: -6
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Do you have a pressure gauge anywere on your setup? Do you have schrader valves? What kind of compressor do you have?
Rich Mondor,
Brockville, ON
77 Hughes 2600
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| Re: Air suspension woes... [message #350331 is a reply to message #350327] |
Mon, 25 November 2019 19:30 |
Shawn Bennear
Messages: 43
Registered: February 2007
Location: Edinburg, PA
Karma: -1
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6cuda6 wrote on Mon, 25 November 2019 18:56Do you have a pressure gauge anywere on your setup? Do you have schrader valves? What kind of compressor do you have?
No pressure gauge yet, It does have schrader valves, and the compressor is a Viair.
http://www.gmcmotorhomeworld.com
1977 Palm Beach, 403 V8 w headers.
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| Re: Air suspension woes... [message #350333 is a reply to message #350325] |
Tue, 26 November 2019 03:28 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Well you have leak somewhere or a compressor that failed.
The air tank is mounted in the same cabinet as the compressor and is usually mounted vertical on the right hand side as you look into the cabinet. It is small. Probably not more than 1 quart.
Does the compressor pump up and shut off even though the bags are not inflating? If it does, then the compressor and tank are OK.
If you are not able to get it up to pressure and the bags are low then the leak could be anywhere. It does not take much of a leak to prevent the whole system from coming up to pressure. I doubt you would hear it leak over the noise of the compressor running. That compressor does not pump much volume of air.
There are several ways to approach this. I guess that I would first disconnect the line from the manifold that goes to the tank and compressor. Then screw in a pressure gauge. The gauge is cheap. You can get one at TSC for around $6.00. With the gauge screwed in to the hose that you disconnected from the manifold, turn on the system. The compressor should fill the tank and shut off at around 1 minute or so with the gauge reading somewhere around 120 PSI. If that happens, let it sit or a few minutes to make sure that it does not leak down quickly.
If it passes the above tests then you can rule out everything to do with the tank, compressor, pressure switch, drain valve on the bottom of the tank, and all of the associated plumbing associated with those items.
I guess the next thing to do would be to reinstall the removed line to the manifold. Then disconnect the lines to the left and right suspension and plug the ports that feed the individual sides. Then try connecting the sides, one at a time, to determine which side is leaking. You will need to use those shutoff valves to prevent the bags from deflating while you are doing this. Or you might put some blocks under both sides prior to disconnecting the lines.
There are several other ways to approach this problem. This is just one that I dreamed up.
Ken B.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] Air suspension woes... [message #350337 is a reply to message #350333] |
Tue, 26 November 2019 07:47 |
Dave Stragand
Messages: 307
Registered: October 2017
Karma: 0
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Your 1977 has ElectroLevel, but my 1978 has ElectroLevel II. The EL II has one compressor and one electronic leveling switch per side. All of the valves are in the compressor itself. All of the valves are in the compressor itself. EL I is much different.
Do you have isolation valves at the bags? Something with a Schrader valve to blow it up that way?
-Dave
1978 Transmode near Pittsburgh
> On Nov 26, 2019, at 4:28 AM, Ken Burton via Gmclist wrote:
>
> Well you have leak somewhere or a compressor that failed.
>
> The air tank is mounted in the same cabinet as the compressor and is usually mounted vertical on the right hand side as you look into the cabinet. It
> is small. Probably not more than 1 quart.
>
> Does the compressor pump up and shut off even though the bags are not inflating? If it does, then the compressor and tank are OK.
>
> If you are not able to get it up to pressure and the bags are low then the leak could be anywhere. It does not take much of a leak to prevent the
> whole system from coming up to pressure. I doubt you would hear it leak over the noise of the compressor running. That compressor does not pump much
> volume of air.
>
> There are several ways to approach this. I guess that I would first disconnect the line from the manifold that goes to the tank and compressor. Then
> screw in a pressure gauge. The gauge is cheap. You can get one at TSC for around $6.00. With the gauge screwed in to the hose that you disconnected
> from the manifold, turn on the system. The compressor should fill the tank and shut off at around 1 minute or so with the gauge reading somewhere
> around 120 PSI. If that happens, let it sit or a few minutes to make sure that it does not leak down quickly.
>
> If it passes the above tests then you can rule out everything to do with the tank, compressor, pressure switch, drain valve on the bottom of the tank,
> and all of the associated plumbing associated with those items.
>
> I guess the next thing to do would be to reinstall the removed line to the manifold. Then disconnect the lines to the left and right suspension and
> plug the ports that feed the individual sides. Then try connecting the sides, one at a time, to determine which side is leaking. You will need to
> use those shutoff valves to prevent the bags from deflating while you are doing this. Or you might put some blocks under both sides prior to
> disconnecting the lines.
>
> There are several other ways to approach this problem. This is just one that I dreamed up.
>
> Ken B.
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana
>
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1978 Transmode (403)
Pittsburgh, PA
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| Re: Air suspension woes... [message #350338 is a reply to message #350325] |
Tue, 26 November 2019 08:02 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Start in compressor cabinet and check pressure at tank drain on bottom of tank. The tanks rust from inside out and get perforated pin hole leaks. If leaks exceed compressor output you are not going to raise. Simple inspection and listen test. JimK has nice stainless replacement tanks.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Air suspension woes... [message #350341 is a reply to message #350338] |
Tue, 26 November 2019 10:54 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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JohnL455 wrote on Tue, 26 November 2019 08:02Start in compressor cabinet and check pressure at tank drain on bottom of tank. The tanks rust from inside out and get perforated pin hole leaks. If leaks exceed compressor output you are not going to raise. Simple inspection and listen test. Jim K has nice stainless replacement tanks.
That is exactly what I was thinking but did not want to say it until he did some more diagnosis. There are just too many other things that it could be. In my case it was a 20 year old fitting that decided to crack it's own.
I wanted to see if his problem is on the supply side (before the valves) or in the valves and hoses beyond there. After that is determined we can diagnose it farther from there.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] Air suspension woes... [message #350343 is a reply to message #350341] |
Tue, 26 November 2019 12:49 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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What Air bags are on the coach?
Some of the bags will not allow air to enter is it is down all the way, so
you need to raise it a little to overcome the restriction.
On Tue, Nov 26, 2019 at 8:56 AM Ken Burton via Gmclist <
gmclist@list.gmcnet.org> wrote:
> JohnL455 wrote on Tue, 26 November 2019 08:02
>> Start in compressor cabinet and check pressure at tank drain on bottom
> of tank. The tanks rust from inside out and get perforated pin hole leaks.
>> If leaks exceed compressor output you are not going to raise. Simple
> inspection and listen test. Jim K has nice stainless replacement tanks.
>
>
> That is exactly what I was thinking but did not want to say it until he
> did some more diagnosis. There are just too many other things that it could
> be. In my case it was a 20 year old fitting that decided to crack it's
> own.
>
> I wanted to see if his problem is on the supply side (before the valves)
> or in the valves and hoses beyond there. After that is determined we can
> diagnose it farther from there.
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana
>
> _______________________________________________
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> Unsubscribe or Change List Options:
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--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.appliedgmcrvparts.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: [GMCnet] Air suspension woes... [message #350355 is a reply to message #350347] |
Wed, 27 November 2019 07:02 |
Bruce Hart
Messages: 1501
Registered: October 2011
Location: La Grange, Wyoming
Karma: 5
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Shawn, if you have the time and the facility to do this. You might
consider removing the manifold, valve assembly, compressor and reseal all
the connections. Replace the O-rings in the skinner valves and bench test
the operation of the pump, pressure valve, and check for leaks on all
connections with soapy water. .
Next in line would be replacing the O-ring in each bag. Once these items
are sealed use soapy water on the rest of the air line connections.
Ken Henderson did a small write up on the skinner valves in this posting
gmc.mybirdfeeder.net/GMCforum/index.php?t=msg&goto=254825&rid=2253&srch=skinner+valves#msg_254825
You can find the electrical schematics From the 1977 / 1978 Maintenance
Manual Suppliment
Chassis Area
1977 / 1978 with Electro Level I
(Models
ZEO6581, ZEO6584) (520kb)
http://www.bdub.net/wirediagrams/77-78-chassis-electrolevel-I.pdf
On Tue, Nov 26, 2019 at 6:41 PM Shawn Bennear via Gmclist <
gmclist@list.gmcnet.org> wrote:
> jimk wrote on Tue, 26 November 2019 13:49
>> What Air bags are on the coach?
>> Some of the bags will not allow air to enter is it is down all the way,
> so
>> you need to raise it a little to overcome the restriction.
>>
>>
>>
>> --
>> Jim Kanomata
>> Applied/GMC, Newark,CA
>> jimk@appliedairfilters.com
>> http://www.appliedgmcrvparts.com
>> 1-800-752-7502
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
> Jim, It has the factory bag setup on it. I was planning on something
> different down the road, but gotta find this gremlin first...
> --
> http://www.gmcmotorhomeworld.com
>
> 1977 Palm Beach, 403 V8 w headers.
>
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--
Bruce Hart
1976 Palm Beach
Milliken, Co
GMC=Got More Class
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Bruce Hart
1976 Palm Beach
1977 28' Kingsley
La Grange, Wyoming
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| Re: Air suspension woes... [message #350356 is a reply to message #350325] |
Wed, 27 November 2019 09:43 |
6cuda6
Messages: 975
Registered: June 2019
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What i did with mine to start with, as i had the same problem, was install a pressure gauge and a shrader valve....nothing fancy just a shrader valve at the bottom of the tank were the drain would go.....then i grabbed one of those cheap tire pressure gauges that you can clip onto the valve stem and fill your tire with the gauge installed.
I then filled the system with my portable compressor to 120psi and hit the raise switches for each side, one at a time while adding air through the gauge till it lifted and held 120psi approx per side.
Then i shut it down to see what would happen....in my case everything seemed to hold for 4 or 5 days (well i have a tiny leak in the right somewere i need to fix)
What this proved is the solenoids etc work but from the tank back i had a problem.....in fact i had 2 problems....one the one way check valve was stuck open and the system was bleeding back through the compressor.....once fixed i redid the test and again it held but would not pump up....turns out my DANA was pooched.
In your case the compressor works so possibly the check valve etc but without someway of pressurising the system youll never know whats going on.
Rich Mondor,
Brockville, ON
77 Hughes 2600
[Updated on: Wed, 27 November 2019 09:44] Report message to a moderator |
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| Re: [GMCnet] Air suspension woes... [message #352252 is a reply to message #352245] |
Tue, 18 February 2020 15:10 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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We replace lot of our customers fitting with DOT approved fittings.
On Tue, Feb 18, 2020 at 7:18 AM Shawn Bennear via Gmclist <
gmclist@list.gmcnet.org> wrote:
> I actually found the problem...I had to wait for a nice warm day, but the
> issue was that the little plastic fitting on the drivers side height valve
> split, but not enough to come totally apart. replaced the fittings with
> brass, and now it works... actually, even better than before...
>
> In the photo, the split was at the arrow tip...
>
>
> --
> http://www.gmcmotorhomeworld.com
>
> 1977 Palm Beach, 403 V8 w headers.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: Air suspension woes... [message #352260 is a reply to message #350325] |
Tue, 18 February 2020 20:25 |
Carl S.
Messages: 4186
Registered: January 2009
Location: Tucson, AZ.
Karma: 13
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My '75 coach has the Power Level system, but I had a similar thing happen several years ago. It turned out to be an air line to the right side that had melted right above the exhaust pipe. I fixed it and wrapped some insulation around it. Problem solved
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles, Solar battery charging. GMCSJ and GMCMI member
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| Re: [GMCnet] Air suspension woes... [message #352268 is a reply to message #352252] |
Wed, 19 February 2020 04:36 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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jimk wrote on Tue, 18 February 2020 15:10We replace lot of our customers fitting with DOT approved fittings.
This is well worth the effort and time. I replaced all of my plastic connections many years ago and fixed all of my leaks in the process.
Ken B.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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