Len, it’s a ‘73 Power Level system. The tank will be large and under the
batteries in the front passenger-side corner, and the compressor will be
under the driver’s foot where you said.
Greg, several things to check:
1. Look at where the air line (1/4” nylon) goes into one of the rear
airbags. Is there a valve there, with a handle? If so, make sure these are
open. These are not factory but are popular additions.
2. Look on the tank—you’ll have to get on your back in front of the right
front tire and look up. Is there a tire valve anywhere on the tank? If so,
use a shop compressor and put 100 psi in the tank. If the bags fill up, put
the dash valves in Travel and keep filling the tank with shop air until the
rear stabilizes and the tank is higher than about 90 psi. If it holds air
there reasonably, you have a working air system, except maybe for the
compressor. If it never raises, listen for where air is escaping to find
the problem.
3. Does the compressor run? If not, is it getting 12 volts? If not, flip
the lever on the nearby pressure switch to manually force it on, and see if
that makes the compressor run. If so, replace the pressure switch with one
that has a target range of 90-125 psi. If that doesn’t fix it, check the
fuse or look for an add-on switch. If the compressor runs but the tank
never builds pressure, the compressor needs to be rebuilt or replaced. If
the tank fills but the bags don’t, and the dash valves are in Raise or
Travel, the problem is more complex. But one thing at a time.
This article describes how your system works:
http://www.gmceast.com/technical/Denney_Power_Level_System.pdf
The advice to find a local mentor is important. Go to Bdub’s site linked
below and look for the link to the Black List (aka GMC Assist List), in the
upper right corner. You have, as Matt will tell you in a little while, a
whole bunch of new, old friends who want you to have success with your
coach. Be sure to bookmark Bdub’s site—it has everything.
http://www.bdub.net/GMCLinks.html
Rick “usually it’s the compressor or its switchery” Denney
> The compressor should be up front on the frame, drivers side visible when
> the drivers hood is open. It should be blue, sitting on top of a small
> air
> tank.
>
> Len and Pat Novak
> 1978 GMC Kingsley
> The Beast II with dash lights that work and labels you can see!
> Fallbrook, CA new email: B52Rule
>
http://www.gmcmhphotos.com/photos/showgallery.php?cat=4375
>
>
www.bdub.net/novak/
>
>
>
>
>
> -----Original Message-----
> From: Gmclist [mailto:gmclist-bounces] On Behalf Of
> gregorb23
> Sent: Friday, December 07, 2018 1:24 PM
> To: gmclist
> Subject: Re: [GMCnet] 1973 Canyonland rear end not raising????
>
> I am in Barnes Kansas. I let it run on raise for 20 min or so and nothing.
> Where is the compressor? If it is in the rear I did not hear it. Belt
> driven? Thanks for the advice on filling with a compressor to get it moved!
> I still want to fix the air issue figure it will sell for more with that
> going.
>
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--
Rick Denney
73 x-Glacier 230 "Jaws"
Off-list email to rick at rickdenney dot com
