Rear Air Ride Random Drops / Air Blending Door

[myrddin]

Hey guys, I have some questions... my H2 is a 2003 with the air ride in the rear. I have seen the rear drop down over night twice and am confused. I went out over this past weekend and aired up the bags full in the off road mode... I then got under with a soapy spray bottle and started to spray the bags down I spent like 30 min per side and even used my hand to soap it up and did not find any bubbles. I then (the best I could) started to spray the hose from each bag back to the compressor... No bubbles. I also sprayed the compressor where the hose connects on each side, and I didn't see anything... I checked the air stem inside where you can air up things and it was not leaking... I tried to follow the hose to the compressor and check it there and best I could tell it was also fine. The sensors look OK best I know... I think one was replaced right before I got it. But my thoughts are if it were one back sensors it would go down crooked? It does not do it all the time only twice that i noticed so far... no service air suspension on dash, and after I looked it over I left it up in off road mode all night and checked it with a tape... and it did not move a mm... I don't get it... thoughts?

Air blend door... this morning I noticed that i had cold air on one side, and hot on the other... I switched from dash to floor and to defrost and so on a few times and it seamed to even out. I can change from 60 - 90 left and right now but it may be a tad slow (hard to say I could be paranoid)... But I wonder if this was just cause it has been on cold so long and I just thought to try heat... or if this is an early sign of blend door failure.

any help would be great... I like my air ride suspension, and i know its problematic... but I want to keep it all in tact.

thanks in advance

[Easy Ed]

Back in 2006 HUMTECH made a post here http://www.elcovaforums.com/forums/s...air+suspension about "If this is an early model H-2 with A single stage compressor there is a programming update to address your concern, talk to your dealer tech and he should know about it. Likely the service consultant or service manager will not have the info."

Maybe yours hasn't had the update ?

Good luck, Ed

[myrddin]

I wonder how I would know if it was a single stage compressor, or how would I know if it had the programming?

I just came in from being under the truck for an hour; I left it at drive height and got a flash light... For the first half hour I left the truck running, I never seen it drop nor did the compressor come on... the rest of the time I had it shut down and I sprayed everything heavy... no bubbles at all that I was able to find. I took a measurement at the end and I will compare that to what the numbers are in the morning...

I don?t get it... if there is a hole it should leak all the time... not when it wants... and my thoughts are when you air it all the way up it should be more noticeable that nay due to the pressure.

Crazy...

Thoughts?

and thanks for taking the time he help a guy out...

[Easy Ed]

Here is what a dual stage looks like. http://www.amazon.com/HUMMER-COMPLETE-AIR-SUSPENSION-COMPRESSOR/dp/B003P5BP9W/ref=sr_1_1?ie=UTF8&s=automotive&qid=1276051210&sr= 8-1 As for the programming, if you can still find a HUMMER dealer (???) they should be able to run the VIN and tell what has been done to the truck, I'd think ?

Ed

P.S. I am one who elected to convert mine to coils so not to have problems with the system that kept cropping up on me.

[myrddin]

Hmmm... at a glance I do not think mine looks like that... but I will check agn tomorrow...

[Easy Ed]

The 2003 only got the dual stage if the original was replaced for a problem under warranty or for that matter even after the warranty and the owner paid for it. Also, I think it was a year or two before they came out with the dual stage.

Ed

P.S. Re-read the link and it was 2005 when they came out with it.

[myrddin]

IC... so it could be that it needs the reprogram? I will call tomorrow and ask my local Hummer dealer... I know someone over there that might help.

I am pretty sure this is my compressor:

[Easy Ed]

Yup, I bet you are correct that it is what's in your truck.

Ed

[myrddin]

Any idea what all the reprogram does? Like is it a flash for other things as well or just specific to the compressor. My blend door was acting odd today as well, but after I messed with it a bit it started to work better... could have just been one of those days...

woke up and the back end was down, and then I for whatever reason tried the heat, and it was cold at 90 on driver side and hot on pass side... I switched it up and down and moved the heat to cold and back a few times and it seems OK I think for now... I will try it agn in the morning.

[myrddin]

Well my measurement shows it dropped almost 4 inches this morning... I don?t get it... The bags do show some cracking but no bubbles at all when I spray... I guess I am not sure what to do. I am going to take a measurement when I get to work... Ind another when I am done to see if I notice anything.

[myrddin]

When I got to work and parked it I measured about 40 1/4 on the driver side and about 40 3/4 on the passenger side... I will chk agn about 5:00 today when I am headed home. I just called the Hummer dealer and had him check the vin (he asked for last 8 digits) and he said it had no due recalls but would need to hook it up to the GM scan tool to see if it was at the latest revision of the software (he says that is all software on the truck). It will cost 97.00 for them to do that and that is even if it does have the latest code... so I will have to pay no matter what. That is almost one airbag... I wish I had a way to tell exactly what was the problem... I do not want to throw money out the window unless its for what needs to be replaced.

any ideas, is there something that will help me indicate what software is on the truck (like how the compressor acts or what something else does)... And is there anything else I can do to test the bags ot lines or compressor?

I would like some reassurance is all... I do not think its smart to just toss money at it till it is fixed.

[Scarsman]

I am not familiar with the air system, but if it adjusts itself automatically then ther must be a valve somewhere for letting air out. Could there be some dirt or something in the system causing the valve to nt quite seal every time, slowly letting air out? This could explain why it does not do it every time. If the lines and bags are not leaking, then that is all I can think of.

Just throwing out ideas.

[HUMTECH]

Here are the symtoms fo the recalibration issue.
Some customers may comment on a Service Air Suspension message and/or a clicking noise from the rear of the vehicle when the vehicle is shut off and the key is removed from the ignition and/or the ECAS compressor cycles too frequently while the vehicle is running. Also could be opening and closing the exhaust valve letting air out of the system.

[myrddin]

thnx HUMTECH... I will start to pay attention... I do know that it will level its self out when I stop and go, or if I get out with it running... and it will go threw and raise and then it will lower until its where it wants to be... but I do not think it runs at all when you turn the key off... or at least not that i have ever seen?


I will tell you this (for the record so far)
at 2:36 today I measured Pass - 40 3/4 and the driver was 41 3/4

I will measure it agn before I drive home.

[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