Air leak...rear air suspension, it's time to fix it.

Denali n DOO

Original poster
Member
May 22, 2012
5,596
Alright, time to find the rear air system leak. I think a leak because it runs too much in my opinion. I'm getttin out the soap and water and gonna start looking. I read the other thread on this and know the possibilities and some options. The Valve Repair Kit that was mentioned, is it one for each air bag or is the kit for the compressor itself? Where is the compressor located? Does anyone know if there are any diagrams of this system and/or its parts? I'll take pics throughout the repair if I can do it myself...

Thanks.
 

The_Roadie

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Nov 19, 2011
9,957
Portland, OR

Wooluf1952

Member
Nov 20, 2011
2,663
Milwaukee, Wisconsin
The repair kit is for the compressor check valve. Just one kit is needed.

Also, the compressor and valves are above the rear pass tire.
 

Denali n DOO

Original poster
Member
May 22, 2012
5,596
the roadie said:
I found the 2004 Air Suspension section of a manual here: http://gmtnation.com/f23/need-manuals-get-them-here-371/

Hey Roadie, I found the 06 manual and its all in there. I thought that section was owners manuals. That must be what the dealership used when they tried to level the back end long long ago. The passanger side sat lower by an inch and they said they increased it as high as it would go. Not sure why they didn't lower the driver side to get it level:undecided:.

I'll get back with what I find out.

Thanks.
 

Denali n DOO

Original poster
Member
May 22, 2012
5,596
Wooluf1952 said:
The repair kit is for the compressor check valve. Just one kit is needed.

Also, the compressor and valves are above the rear pass tire.

Thanks for the info, gonna be looking for some bubbles soon!!
 

am-radio

Member
Apr 24, 2012
178
Denali n DOO said:
Hey Roadie, I found the 06 manual and its all in there. I thought that section was owners manuals. That must be what the dealership used when they tried to level the back end long long ago. The passanger side sat lower by an inch and they said they increased it as high as it would go. Not sure why they didn't lower the driver side to get it level:undecided:.

I'll get back with what I find out.

Thanks.

My passenger side sits lower than the driver side also. Did they say why it did this?
 

jrSS

Member
Dec 4, 2011
3,950
am-radio said:
My passenger side sits lower than the driver side also. Did they say why it did this?

Because they are idiots and didn't wanna take the time to adjust the airbag sensors accordingly... it can be adjusted
 

am-radio

Member
Apr 24, 2012
178
jrSS said:
Because they are idiots and didn't wanna take the time to adjust the airbag sensors accordingly... it can be adjusted

Does it tell you how to adjust the height in the manual (link above)? Could I do it myself?
 

am-radio

Member
Apr 24, 2012
178
jrSS said:
Because they are idiots and didn't wanna take the time to adjust the airbag sensors accordingly... it can be adjusted

Does it tell you how to adjust the height in the manual (link above)? Could I do it myself?
 

Denali n DOO

Original poster
Member
May 22, 2012
5,596
am-radio said:
Does it tell you how to adjust the height in the manual (link above)? Could I do it myself?

Yes, all the info is in the manual for adjusting the height sensors. if your passanger side is set to the max already then just lower the driver side.
 

jrSS

Member
Dec 4, 2011
3,950
Sensor sits on a bracket. It sits in the wheel well. 2 bolts 10mm (I believe). U loosen the 2 bolts and slide the bracket either to the front of the vehicle or to the back.

Driver side sensor: slide it to the rear of the truck ....lower
slide it to the front of the truck....lift

Passenger side sensor: slide it to the rear of the truck ...lift
slide it to the front of the truck...lower
I did this myself and it works great. But if u wanna lower even more than what the 2 bracket bolts will let u....take the bolt completely out to the front end of the bracket on the vehicle and adjust on either side and POOF down further u go..
 

am-radio

Member
Apr 24, 2012
178
I am going to adjust my rear passenger ride height. It sits about an 1" lower than the drivers side. I read the manual and I want a bit of clarification. Do I have to jack up the truck and support it? Do I have to take the tire off to adjust the right height arms/adjustors? Will the arm slide easily front to back? Should I remove the fuse for the air system? Any idea how much to slide the arm to raise the passenger side 1"?
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
It's just a small sensor. No weight is on it. You loosen the screws and rotate the sensor a small amount - I'd guess 10 degrees at a time. Then drive around for a while and let the controls do their job. Then remeasure. Lather, rinse, repeat. Might take a couple of times to get it nailed, but it's not like it costs anything per experiment except fuel. You may be overthinking it - have you LOOKED at the sensor yet?
 

am-radio

Member
Apr 24, 2012
178
I have looked at it. It did look that simple, but I just wanted to make sure. A great night shift project. Nothing better than getting paid to be at work, but being able to work on your own vehicle.
 

jrSS

Member
Dec 4, 2011
3,950
Just do the directions I posted above. I did not remove my wheels. The openings of the wheels are big enough that I could work thru them. U don't even need to drive around. when u move the sensors the air compressor will either come on lifting the truck up or air will release from the bags bringing u down and u can even here that ...its simple. Someone got an estimate at the dealership and quoted them $400 dollars to do this simple mod. (Just make sure when u lower ur not sitting on ur bumstops if so trim them down, I trimmed mine down to half)
 

am-radio

Member
Apr 24, 2012
178
I tried to do this and I failed. I couldn't get the passenger side to lift up. I tried both ways, and even removed one bolt. I want to lift the passenger side rear end. To lift the passenger side, I'm suppose to move the entire housing (where the 2 bolts go) clockwise. My measurements are:
Front driver = 33"
Rear driver - about 33"
Front pass = 32.5"
Rear pass = 32"
You can definately see the entire truck leaning to the passenger side.

I tried to move the sensor with the truck jacked up and the engine running, but the compressor didn't start or stop. Is there only a certain range where the sensors work, or is there a certain time delay? Am I missing something? This looks like such as easy job and seems idiot proof.
I've also read that the ECAS needs to be recalibrated. Could this be what I need? If so, any instructions on how to do this?
 

jrSS

Member
Dec 4, 2011
3,950
Well on my SS all I did was adjusted sensors from left to right.

Driver side loosen 2 bolts and slide back to the rear end of truck for more DROP.

Pass. Side loosen 2 bolts and slide to front of truck for more DROP.

It takes a lil while for the bags to release air...

If u move sensors in the opposite direction posted above u will lift.....then hear the air compressor kick on. Make sure ur keys are on so the battery is givng some juice.
 

Denali n DOO

Original poster
Member
May 22, 2012
5,596
am-radio said:
I tried to do this and I failed. I couldn't get the passenger side to lift up. I tried both ways, and even removed one bolt. I want to lift the passenger side rear end. To lift the passenger side, I'm suppose to move the entire housing (where the 2 bolts go) clockwise. My measurements are:
Front driver = 33"
Rear driver - about 33"
Front pass = 32.5"
Rear pass = 32"
You can definately see the entire truck leaning to the passenger side.

I tried to move the sensor with the truck jacked up and the engine running, but the compressor didn't start or stop. Is there only a certain range where the sensors work, or is there a certain time delay? Am I missing something? This looks like such as easy job and seems idiot proof.
I've also read that the ECAS needs to be recalibrated. Could this be what I need? If so, any instructions on how to do this?
If you can't raise the passenger side maybe it's at it's upper limit already why not try to lower drivers side so it's level.

One of the members reported that after he changed from stock air bags to Armott air bags his back end was leveled out. I forgot who posted that.
 

am-radio

Member
Apr 24, 2012
178
I did try lower the drivers side rear, but put it back to where it was. The Denali sits low enough as it is (mud flaps and running boards). Need to figure out how to lift my passenger side. I still have the stock air bags.
 

n0kfb

Member
Dec 8, 2011
104
Denali n DOO said:
Alright, time to find the rear air system leak. I think a leak because it runs too much in my opinion. I'm getttin out the soap and water and gonna start looking. I read the other thread on this and know the possibilities and some options. The Valve Repair Kit that was mentioned, is it one for each air bag or is the kit for the compressor itself? Where is the compressor located? Does anyone know if there are any diagrams of this system and/or its parts? I'll take pics throughout the repair if I can do it myself...

Thanks.

Let us know what you find, if anything. Mine has run too often since new, and the dealer said everything was fine. I tried to escalate within GM to find out what the engineering types intended, but got nowhere.

Best of luck!

-- Dan Meyer :coffee:
 

northcreek

Member
Jan 15, 2012
3,110
WNY
Denali n DOO said:
Alright, time to find the rear air system leak. I think a leak because it runs too much in my opinion. I'm getttin out the soap and water and gonna start looking. I read the other thread on this and know the possibilities and some options. The Valve Repair Kit that was mentioned, is it one for each air bag or is the kit for the compressor itself? Where is the compressor located? Does anyone know if there are any diagrams of this system and/or its parts? I'll take pics throughout the repair if I can do it myself...

Thanks.

Before you do anything,check to see if the led at the inflator station is flashing an 001,002 or 003 code....just sayin'..Mike.
 

am-radio

Member
Apr 24, 2012
178
Just an update. I cranked the passenger side sensor counterclockwise as it would go. Started the truck and nothing. I drove around for 5 minutes and finally the compressor turned out and lifted the passenger side. I've been driving around now for 30 minutes and I'm finally level. I guess just adjusting it and not driving around wouldn't work for me.
 

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