Rear Air Ride Random Drops / Air Blending Door

[myrddin]

Checked when I got out of work was the same as 2:30 ( Pass - 40 3/4 and the driver was 41 3/4)

Checked after my drive home:
Driver - 41 1/2
Passenger - 41

I guess I will chk it later tonight. I dont know what to do at this point.

[Easy Ed]

Hate to say it but ya just got to let them run the scan tool on it, check for any codes and check the software for any updates. They may even be able to tell you what is wrong with the heater/ac problem also while doing the scan. It is a painfull thing to pay for but no a days it is the only way to keep from throwing money at it hoping to find the problem. I have a power programmer that will also read the codes and clear them and point me in the correct direction to fix most things, it helped me when the memory module went bad in the drivers seat.

HUMTECH is a great person that takes the time to help us out here but I think he will agree that checking for codes and the software version is a good thing at this point to help resolve your problems.

Agreed HUMTECH ??

Ed

[HUMTECH]

Absolutley i agree. Software problems can be impossible to diagnose you just kinda have to put faith in the writers. I fix probably 2 to 4 problems a week on average with software updates. Sometimes just reloading the current software can fix an issue just like restarting a pc or reinstalling software on a pc to correct for some glitches. Thanks for the kudos Ed...

[HUMTECH]

Also if there was a level sensor replaced the ride height calibration needed to be done, if not that will cause issues as well. The dealer can check in the data list if it is learned or not. another thing to check to get your moneys worth

[Easy Ed]

You are welcome. Just giving credit where credit is due

Originally Posted by HUMTECH

Thanks for the kudos Ed...

[myrddin]

I understand... I just don’t get how the software can let the rear drop over time like that... Seems like I could hear it or something...

Currently at: This is as of 8:25pm...
Passenger 40 3/4 best I can tell
Driver 41 1/2 (-2 mm)


So let’s look at it like this, its dropping, so air is coming out of something... Is there an exhaust valve that has a vent for the air? Would it be dumb to try to put a balloon over it to see it shows signs or air escaping?

What if it’s a leak somewhere I can’t see to spray?

Man, it’s bad enough when you need to work on something but usually you know what it is.


The air is currently working, it was just the one time... but like you stated... could be sign of what is to come.

If you guys say its worth my time then I will do it... I just wish I had more signs to point my finger at is all.

I did find this and I am not real sure what it means (like what had to be fixed) but:
Suspension & Steering: SUSPENSION:REAR
Service Bulletin Number: 3472
NHTSA Number: 10014856
Model Years Affected: 2003, 2004, 2005
Date of Bulletin: 05/2005
Bulletin Summary: REAR END OF THE VEHICLE APPEARS TO SAG AFTER THE VEHICLE SITS OVERNIGHT OR LONGER.

located: http://repairpal.com/hummer-h2-2003/recalls_and_tsbs

[myrddin]

OK, I just got off the phone with a Hummer tech; he knew quite a bit and had some good info to offer. He says if i have the code 711 it could be that I need the update and it might be ok... However he said the 2003 suffers from having a bad system... he says the new dual compressor fixed all the problems... He says that the single failed in many ways but the most common was corrosion build up or debris that causes the exhaust valve to hang and leak air... he stated that sometimes it could not hang because the decree would move but then it might end back where it hangs up the valve... but he said if I want to test it I can remove the gas cap, and then remove the filler neck surround ( 3 screws and turn counter clockwise) and move the filler neck to the side I will see the filter and exhaust line... he says easiest thing to do is place a condom over the filter for the exhaust hose and let it sit and if I see air fill it up overnight I will know that it how the air is escaping.

So now I have another thing to test...

He did say the code read would be 50/50 but the fix now or later will be the upgraded compressor... like 2500.00 worth of parts.... that I do not have at the moment.

what do you guys think?

[myrddin]

just found out when the guy replaced the driver side level sensor that he did not have it recalibrated... says he just swapped it out... wondering if that would cause it to drop a few times like I have seen? Over 30 days I have seen it lower than normal 3 times... all other times it?s been pretty close to what I would expect...

[myrddin]

Part One of Bag Replace...

OK, So I got the bags today, and they are in fact the same ones on it "Factory"... I jacked up the tuck from the rear end as high as my 3 ton would go (not as high as I would have liked). Then I put jack stands under each side of the frame for support and chock/blocks in front of each tire. I then let the jack down all the way (well till the tires were back on the ground)... then I took my knife to the bags... note the passenger had little air in it (or at least compared to the other it had way less pressure). After which to give me more room I cut the bags in half to give me more access... Now the hard part is really (or at least so far) getting the lines off... Only way I could do this was to push the retaining clip in and turn counter clockwise to take the top of the bag out of the frame... then I used both of my index fingers to hold down the metal ring on the bag where the hose connects to it and it tried to hold the line as well and pull, at one point I could not hold the line and gave a tug anyway and it popped out... If you had a buddy here to hold the line as you pulled the bag it would make short work of this. Once I got them both out I said to myself it?s a great time to clean the frame up and use my Eastwood frame restore kit I had sitting on a shelf So I will continue on tomorrow with shots of the frame clean up... I hope this will benefit someone in the future... But just know it is an easy job over all (So Far).

Pics:

[HUMTECH]

#PIT3509: 2003-2005 Hummer H2 Vehicle Sits Low or the Suspension Sags Overnight - keywords AIR control DTC ECAS ELC electronic height inoperative leak MIL module rear spring trim - (Mar 23, 2005)

Subject:2003-2005 H2 Hummer Vehicle Sits Low or the Suspension Sags Overnight

Models:

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in the PI.
<A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=1634083&from=sm#ss1-1634083">Condition/Concern:

Some customers may comment that the rear of the vehicle sits low and/or the suspension sags overnight.
<A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=1634083&from=sm#ss2-1634083">Recommendation/Instructions:

Check the following locations for a leak using a soap and water solution in a spray bottle.

1. <LI type=1>Left and Right Inlet Valves. <LI type=1>Exhaust Valve. <LI type=1>Suspension Air Supply Lines that run from the Inlet Valves to the Right and Left Air Springs (Airbags).
2. Air Spring fittings and the Air Spring itself.

Leakage can produce big bubbles or just some beer like foam appearance. If the leak is isolated to the valve block assembly, do not replace the entire compressor assembly. The valve block can be obtained separately by ordering part number 88982408 for the single stage compressor or part number 89060584 for the dual stage compressor.
Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
<A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=1634083&from=sm#ss3-1634083">Models:

(2003-2005 Hummer H2)

[HUMTECH]

#PIT3472: 2003-2005 H2 Hummer Rear Suspension Sags/Leak Down Specification - keywords AIR DTC ECAS ELC electronic height inoperative MIL Module trim - (Mar 4, 2005)

Subject:2003-2005 H2 Hummer Rear Suspension Sags/Leak Down Specification

Models:

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in the PI.
<A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=1618502&from=sm#ss1-1618502">Condition/Concern:

Some customers may comment that the rear end of the vehicle appears to sag after the vehicle sits overnight or longer. After the vehicle is started, the rear of the vehicle rises to normal operating level.
<A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=1618502&from=sm#ss2-1618502">Recommendation/Instructions:

To correctly measure for a concern, use the rear suspension "D" height measurement. The D height is obtained by measuring the distance between the edge of the jounce cup along the jounce bumper center line and the jounce pad on the rear axle (See SI Document ID # 796914).
A 1.0 mm (0.040 in) leak down drop of the rear end over a 24 hour period is considered normal.
Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
<A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=1618502&from=sm#ss3-1618502">Models:

(2003 - 2005 H2 Hummer)

[MJB_Hummer]

Do you live somewhere where it gets cool or cold at night?

I had the same exact symptoms and also could not locate a leak with the soapy water. The problem is that when the bags are at normal ride height they fold over on themselves and when it is warm out, say 50 to 60+ degrees out they will not leak because the rubber is soft. But when it gets colder out the rubber is stiff and it will leak from the crease, I replaced the bags and problem solved. Everyone says to go to springs, but I like the air ride and the bags are cheap and very easy to replace. Did it in just over an hour.

[Hummerguy32]

Just Today went to the hummer dealer and had them reprogram the code from humtech requested it cost me 105.00 They said it took some time for the computer to accept the new code...whatever that means?? And then they charged me 63.00 additional dollars to adjust carring heights on the airbags... What a joke. Is this even reality or is it something they just made up?? Thanx Humtech.