Please read and let me know if I'm on the right track.

[Jayman]

I'm excited to be here to experience the expertise which Trailvoy once offered. It was by fluke I found it - I believe it was meant to be!
I have been dealing with a rear air spring suspension issue and am about to try a new compressor next. I was hoping to have you read through and let me know if you agree that it makes sense to purchase one or not.
Air suspension compressor and Arnott springs - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum
My diagnosis efforts begin on page 2 FYI.
Really appreciate it everyone - thank you!
Jay

 

[Jayman]

Instead of following the link here's the situation I'm facing.

Okay maybe this will shed some light on the situation.
The new bags I installed - only the passenger side is inflated. The driver side has no air in it at all yet it is still level at the back, just riding low. I checked the air line and its secure. What might cause this? Compressor lines are tight too.
So after doing more reading I decided to use my garage compressor and inflate through the service port in the rear. Both bags are now inflated and sitting nice at normal ride height. I turned on the truck compressor from the switch and the pressure reads about 75lbs so it seems to be putting out enough pressure.
If it won't run and do its job from this point I can only assume there is an issue with the compressor putting out to the springs themselves. I may have to bite the bullet and invest in a new compressor unless you guys have something for me? Also the compressor won't run on its own while the truck is running and already the air has leaked out of the springs for the most part so I'm pretty much aligned with a new compressor. The information I posted above was in the hope that some would see what's been done and conclude which repair was actually required as opposed to just throwing parts at it.

 

[jrSS]

Ummm u could replace ur bags with coils and never worry about this issue again

 

[RayVoy]

Ok, a number of observations,
- the compressor won't run if the height is at "normal ride" height,
- the air should not have leaked out of the bags in a couple of hours,
- the compressor is not as big/fast as one we might use in the garage,
- because it is not very big, it can not keep up to air leaking out of a large hole.

I think you have a leak.

Run soapy water over the entire system, lines and bags.

 

[Jayman]

Ummm u could replace ur bags with coils and never worry about this issue again

Appreciate your reply and I am aware of that option. As you can see above I've installed new air springs and my intention is to keep the factory system

 

[The_Roadie]

Could be a sensor issue. Troubleshooting that system is not easy even if you have a Tech II tool because it doesn't talk on the data bus. Diagnostic information is only available on the LED near the inflator switch. Is that light flashing at all?

 

[Jayman]

Could be a sensor issue. Troubleshooting that system is not easy even if you have a Tech II tool because it doesn't talk on the data bus. Diagnostic information is only available on the LED near the inflator switch. Is that light flashing at all?

No flashing lights back there - I should have mentioned that. However speaking of sensors you might be on to something. Is it possible they could move when driving around with little or no air due to severe bouncing? I ask because on the 07 both sides of the sensors point from front to back, meaning from where its bolted it points down and rearward. On the 02 the driver side point toward the front and down but the other side is the same as the 07. I'm wondering if this is a difference between years, or, is this why that spring is not inflating which I guess may be why the compressor doesn't run, as long as the right side has all the air it needs. I have the truck in the garage now.

 

[Jayman]

I've done a lot of reading. If I'm not mistaken, 2 or 3 flashes would indicate a faulty sensor left or right which I don't have.
What I haven't been able to find is how to determine if the level sensors are out of adjustment. I really don't get the "D" height etc. It doesn't make sense to me.
So any tips on how to check sensor height?

 

[Jayman]

I'm in the process of adjusting the driver side sensor. It was nowhere near close to the other side (I mean way off) with no sign of recent movement and tight bolts.
I seem to have found most of what I need except for this; "Trim Height Specifications in Suspension General Diagnosis." What I'm looking for is correct "D" height.
Can one of you look this up for me please?
Its pushing 1am and I would REALLY appreciate it!

 

[Jayman]

Just finished putting it back together and went for a drive. The compressor runs for a while (50 second) and shuts off. So when parked I turned it from key off to key on until the compressor would no longer run. Its as though its reached the correct ride height according to the sensors which unfortunately is way too low still. I adjusted the driver side to match the passenger using the drill bit to line up the holes. It really hasn't made much of a difference. The compressor does run briefly when driving too BTW.
All I can think of is perhaps I messed up the adjustment on both sides when I installed the air springs originally which is why I'd like to find the correct "D" height measurements. Once that's done and correct if its still not lifting properly I guess I'll try a compressor. Thoughts or help?

 

[Juicy K]

How far off is the ride height of the two? I played with my sensors to level my truck out and it took me quite a few times to get my fender gap the same. I did not see if you tried the soapy water on all the lines. But I would check on that for sure if you haven't.

 

[Jayman]

How far off is the ride height of the two? I played with my sensors to level my truck out and it took me quite a few times to get my fender gap the same. I did not see if you tried the soapy water on all the lines. But I would check on that for sure if you haven't.

The truck was fairly level from left to right (perhaps slightly down on left). The ride height is too low at the rear. I guess I figured if I had a leak it would run until it overheated. It doesn't for more than 50 seconds.
Do you know the correct "D" height measurements?