Auto Air Ride Compressor Repair

I know few people have had "check suspension system" codes and their rear shocks dont air up anymore. This happened to my 2008 Yukon Denali with auto ride rear suspension.

It has Tonys Belltech kit with the 2/4 drop on it. I installed the kit about exactly one year ago (I remember cause it was cinco De Mayo last year, if you get the relation, lol).

About a month or two ago it started giving me an error code "check suspension system" and it wouldn't air up. Rear shocks were soft with no air at all. The rear started sagging and id hear some rubbing around some sharper turns. Scanned the codes with the BCM scanner and it gave me C0660 Exhaust valve circuit fault.

After some research on All Data and my engineer friend at GM, we figured out that a possible cause could be what some people were stating as " a white wire was rubbing against the frame and corroded". Figured this might be the scenario as it would randomly work once in a while. By looking under the truck it wasnt obvious where this white wire was, but after removing the compressor, it was pretty obvious. Here are some pics i took


You could tell truck had the rear down a bit. measured Driver 34.5 and pass 34.25 on the rear.



On the pass side behind rear wheel the compressor hides...we noticed that the bushings were pretty loose and worn out...still have to replace or come up with something sturdier.
http://www.youtube.com/watch?v=e3A-LOYgtik

Here is the compressor removed, and you can see the white wire exposed and corroded...it literally was about 1/2 of corrosion under the wire coating.





We opened the little assembly to the right...it was sealed and had an oring at the bottom...not sure what this does, but we were careful not to damage anything.



..and the wires ran inside...



We basically just extended the wire, sottered, resealed with rtv and put it back together.





Put everything back together with more protection around the wiring so it doesnt rub again.


Started it and aired right up. Stance with air up: 35.5 and 35.25 on rear fender heights



Hope this saves someone some money on a new compressor if its just a tiny wire corroded.

Id like to thank my friend Don for all the help, Mike for the scan codes and Tony for all the quick replies.

glad you got it fixed something new all the time goes wrong right lol.

Sidenote looks a lot better lower in the rear. Cut the bracket off and do it lol

LOL It rode like crap tho at the lower stance...what bracket are you talking about?

yes because your bracket is still there. Cut the rear bumpstop bracket off the truck add the shorter bumpstops and endlinks and you will be good. This is the same set up I have in my escalade and my 67 year old mom driving on a trip 2 weeks ago had no problem with the ride. HOnestly all the guys that have been in my escalade have commented how good it rides. Mine does ride a little stiffer since I have the spohn bars and the front/rear swaybars but its nothing bad at all.

305 35 24 im at 34.5 from ground to fenderlip in rear. Trucks ive done on autoride at 34.5 and bumpstop brackets still in there its not enough travel.

Will look into that...

At the 35.5 setup as i have in my last pic, it rides good, only complaint i have is when i had full load of five people in the car and a friend in the third row seating...he was bouncing too much in the third row...what would cause that?

Cut the bracket off the frame in the rear and add the djm links/shorter bumpstops and call it good.

Have you had anymore service suspension lights since. I know it has been a bit but just seeing if that was the end of it. Thanks for the info.

Good write up, this needs to be a STICKY

07whitehoe said:

Have you had anymore service suspension lights since. I know it has been a bit but just seeing if that was the end of it. Thanks for the info.

Click to expand...

No check suspension codes since at all. Don't know if my compressor is old or whatnot as it seems lil loud but it works perfect.

I think this compressor is getting louder and louder as time goes on...anyone have this issue as well?? its not just a background noise anymore like it used to be, anyone that is in the car when it airs up asks what the hell is that...