height control valve

dan vanderknaap

New member
May 24, 1998
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I just completed my 1st long trip in the GMC - 3 days, 3 nights and 928 miles.
One of the highlights of the trip was getting to meet and visit with Mike
Beaton in N.S.
His hosptitality was greatly appreciated, especially considering the 15 minutes
notice I gave him (g).

Now for the one problem I encountered. At startup the compressor ran for an
unusually
long time. The third time this happened the compressor overheated (smoke,no
fire!). At 1st I thought that the slow leak I have had for a while had gotten
worse. But running without the compressor on, the system does not leak down any
faster than before( a few days). I could hear air escaping the passenger side
height control valve vent for a short time and also from the valve on the bottom
of the little tank beside the compressor (Dana inside the coach). Inspecting the
compressor I found the line out melted at the outlet on the head. Also after
removing the front cover I found the 2 gears had moved forward on their shafts
and had scuffed it on the inside.
Can a faulty height control valve allow air to escape through it's vent so that
the compressor runs continuously but not allow the airbag to deflate ?
Any help or suggestions would be much appreciated.
If I can't resolve this by Friday I will install schrader valves on the airbags
as I am planning to leave then for the Nascar race in New Hampshire .

Dan Vanderknaap
76 Palm Beach
 
Dan,
The height control valves are wonders of reliability. I thought I had one
leaking a while back cause I could hear it. It turned out that the air line
running to it had rubbed the side of the coach so many years it had worn
through. How old are your air bags? Real old one develop pin hole leaks
and go down in 3 or 4 days. I suggest using a spray bottle with soapy water
to leak check the bags, all fittings inside and out and check for chaffing.
Change to the Thompson air pump if your Dana is shot. Someone on the
mailing list sells them with instructions at a good price. I'll look them
up if you need it and they don't respond. Also look on both the Western
States Club internet site and Gene's site for good information. BTW, the
schrader valves and a good portable compressor can certainly get your to the
race. I think the bags require 80 psi or more pressure.
Good luck.
Bob McLaughlin

- -----Original Message-----
From: owner-gmcmotorhome
[mailto:owner-gmcmotorhome]On Behalf Of Dan Vanderknaap
Sent: Monday, July 03, 2000 9:36 PM
To: gmcmotorhome
Subject: Re: GMC: height control valve

I just completed my 1st long trip in the GMC - 3 days, 3 nights and 928
miles.
One of the highlights of the trip was getting to meet and visit with Mike
Beaton in N.S.
His hosptitality was greatly appreciated, especially considering the 15
minutes
notice I gave him (g).

Now for the one problem I encountered. At startup the compressor ran for an
unusually
long time. The third time this happened the compressor overheated (smoke,no
fire!). At 1st I thought that the slow leak I have had for a while had
gotten
worse. But running without the compressor on, the system does not leak down
any
faster than before( a few days). I could hear air escaping the passenger
side
height control valve vent for a short time and also from the valve on the
bottom
of the little tank beside the compressor (Dana inside the coach). Inspecting
the
compressor I found the line out melted at the outlet on the head. Also
after
removing the front cover I found the 2 gears had moved forward on their
shafts
and had scuffed it on the inside.
Can a faulty height control valve allow air to escape through it's vent so
that
the compressor runs continuously but not allow the airbag to deflate ?
Any help or suggestions would be much appreciated.
If I can't resolve this by Friday I will install schrader valves on the
airbags
as I am planning to leave then for the Nascar race in New Hampshire .

Dan Vanderknaap
76 Palm Beach
 
Dan,

Yes, the height control valve can easily leak & cause the compressor to
overheat. The height control valves see tank pressure on Power Level &
Electro Lveel I. Electro Level II is a different animal all together.

You can try to take the unit apart & clean it or do the simpler job of
putting in a new one.

I would also install a shut/ fill system to the air bags to give you an
option of direct filling the bags without having the consideral manual job
of installing schraeder valves. You never know when this situation could
happen again, be prepared!!

Hope this helps,

JIm Bounds
- ----------------------

>I just completed my 1st long trip in the GMC - 3 days, 3 nights and 928
miles.
>One of the highlights of the trip was getting to meet and visit with Mike
>Beaton in N.S.
>His hosptitality was greatly appreciated, especially considering the 15
minutes
>notice I gave him (g).
>
>Now for the one problem I encountered. At startup the compressor ran for an
>unusually
>long time. The third time this happened the compressor overheated (smoke,no
>fire!). At 1st I thought that the slow leak I have had for a while had gotten
>worse. But running without the compressor on, the system does not leak
down any
>faster than before( a few days). I could hear air escaping the passenger
side
>height control valve vent for a short time and also from the valve on the
bottom
>of the little tank beside the compressor (Dana inside the coach).
Inspecting the
>compressor I found the line out melted at the outlet on the head. Also after
>removing the front cover I found the 2 gears had moved forward on their
shafts
>and had scuffed it on the inside.
>Can a faulty height control valve allow air to escape through it's vent so
that
>the compressor runs continuously but not allow the airbag to deflate ?
>Any help or suggestions would be much appreciated.
>If I can't resolve this by Friday I will install schrader valves on the
airbags
>as I am planning to leave then for the Nascar race in New Hampshire .
>
>Dan Vanderknaap
>76 Palm Beach
>
>
>