Chuck --
Either your ride height valves are bad or mis-adjusted (10% chance they'd
both fail). Have you ever heard the ride height valves expel air? Here's a
simple test:
Put both sides in the raise position. Wait on the coach to go up. Center
switch in 'auto', left and right in the center. Get out, walk up by the rear
wheels. In 10-30 seconds, you should hear the hiss of air being let out of
the bags. It isn't real loud.
If you don't hear it, the ride height valves are bad or misadjusted, or the
outlet is plugged so they can't vent.
If you hear air being vented, then the three way valves that are closest to
the pressure manifold are leaking through. (90% chance they'd fail). They
leak internally and increase the coach height.
Solutions:
1). Adjust or replace the ride height valves.
2). Live with it. Use this procedure:
A). Set level to 'auto', let the coach level, compressor turn off.
B). Set level to 'hold', occasionally to 'auto' about once an hour while
driving if you feel your butt's dragging. (The coach, not yours).
3). Fix or replace the bad 3 way valves.
Do you want/need a trouble shooting technique for the three way valve
diagnosis?
Mark Grady
'77 Kingsley
N Webster, IN
mgrady
> -----Original Message-----
> From: owner-gmcmotorhome
> [mailto
wner-gmcmotorhome]On Behalf Of Chuck Will
> Sent: Friday, November 20, 1998 11:58 AM
> To: gmcmotorhome
> Subject: Re: GMC: air bag pressure & adjustment of pressure switch
> (reply)
>
>
> Ok, When I am parked and the engine is off and the switches are
> in hold I have no
> leaks. When I turn on the engine and turn the rocker to AUTO it
> pumps to the
> correct level and turns it self off. while driving down the road
> the compressor
> comes on periodically momentarily one of those words, but not for
> long, In the
> mountains it seems to do it more. What happens is that when I
> get to where I am
> going the coach is as high as it can get, no air has been
> released to keep it at
> the 11 inches. I must assume at this pint I have no leaks, not
> even the ones I am
> supposed to have. chuck
>
>
> > Chuck
> >
> > Understand that what I am going to say is from what I have read not
> > what I know. GMC was having so much trouble with the air suspension
> > system that even they said to put it in hold for a while. What
> you want to
> > do is put it in travel when you are on the road. This lets the automatic
> > leveling feature work the way it was supposed to. When you put
> it in hold
> > it adjusts to nothing. Get all the leaks out and it will work the way it
> > should. Its is even fun to have the old gal hiss at you.
> >
> > Please understand this is the info I have read not what I have
> experienced.
> >
> > Take Care
> > Arch 76 GB IL
> >
> > >
> > > Tell me more. Is this for the earlier models or all models.
> I was told
> > > to put
> > > the air ride on auto for the first five minutes and then to
> turn the rocker
> > > to
> > > hold. What is my warning to do the hold thing and what
> happens. I have
> > > been
> > > doing this for 10 years and have had no problems. Chuck
> Ifd I am doing
> > > something wrong please let me know soon.
> > >
>
>
>
Either your ride height valves are bad or mis-adjusted (10% chance they'd
both fail). Have you ever heard the ride height valves expel air? Here's a
simple test:
Put both sides in the raise position. Wait on the coach to go up. Center
switch in 'auto', left and right in the center. Get out, walk up by the rear
wheels. In 10-30 seconds, you should hear the hiss of air being let out of
the bags. It isn't real loud.
If you don't hear it, the ride height valves are bad or misadjusted, or the
outlet is plugged so they can't vent.
If you hear air being vented, then the three way valves that are closest to
the pressure manifold are leaking through. (90% chance they'd fail). They
leak internally and increase the coach height.
Solutions:
1). Adjust or replace the ride height valves.
2). Live with it. Use this procedure:
A). Set level to 'auto', let the coach level, compressor turn off.
B). Set level to 'hold', occasionally to 'auto' about once an hour while
driving if you feel your butt's dragging. (The coach, not yours).
3). Fix or replace the bad 3 way valves.
Do you want/need a trouble shooting technique for the three way valve
diagnosis?
Mark Grady
'77 Kingsley
N Webster, IN
mgrady
> -----Original Message-----
> From: owner-gmcmotorhome
> [mailto
wner-gmcmotorhome]On Behalf Of Chuck Will> Sent: Friday, November 20, 1998 11:58 AM
> To: gmcmotorhome
> Subject: Re: GMC: air bag pressure & adjustment of pressure switch
> (reply)
>
>
> Ok, When I am parked and the engine is off and the switches are
> in hold I have no
> leaks. When I turn on the engine and turn the rocker to AUTO it
> pumps to the
> correct level and turns it self off. while driving down the road
> the compressor
> comes on periodically momentarily one of those words, but not for
> long, In the
> mountains it seems to do it more. What happens is that when I
> get to where I am
> going the coach is as high as it can get, no air has been
> released to keep it at
> the 11 inches. I must assume at this pint I have no leaks, not
> even the ones I am
> supposed to have. chuck
>
>
> > Chuck
> >
> > Understand that what I am going to say is from what I have read not
> > what I know. GMC was having so much trouble with the air suspension
> > system that even they said to put it in hold for a while. What
> you want to
> > do is put it in travel when you are on the road. This lets the automatic
> > leveling feature work the way it was supposed to. When you put
> it in hold
> > it adjusts to nothing. Get all the leaks out and it will work the way it
> > should. Its is even fun to have the old gal hiss at you.
> >
> > Please understand this is the info I have read not what I have
> experienced.
> >
> > Take Care
> > Arch 76 GB IL
> >
> > >
> > > Tell me more. Is this for the earlier models or all models.
> I was told
> > > to put
> > > the air ride on auto for the first five minutes and then to
> turn the rocker
> > > to
> > > hold. What is my warning to do the hold thing and what
> happens. I have
> > > been
> > > doing this for 10 years and have had no problems. Chuck
> Ifd I am doing
> > > something wrong please let me know soon.
> > >
>
>
>
