Rear Air Ride Random Drops / Air Blending Door

[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]

Well I am not sure if the fact that when the guy replaced the sensor on the driver?s side may have added to this... suspect not or it wouldn?t work at all... But with me only seeing it drop 3 times in over 30 days now I am going to hold on replacing... but in the same time work on getting the upgraded compressors for future use. I just can?t see guessing at what to replace... for all I know HUMTECH is right and the programming needs to happen... he is the expert not me... So I may replace the bags myself since they do show signs or dry rot and I will take to the Hummer dealer to have them reprogram the truck and chk the level and trim... If they find codes I will make note and work it from that direction... thoughts are that at least it will limit the guess work... and if they say I just need to replace the compressor... then I know my direction for sure.

I found this on eBay and I was wondering if the bags were worth the money, or should I only replace with the firestone brand:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=330453332305&ssPageNam e=STRK:MEWAX:IT



I just let a used 2007 dual stage compressor go... I hope I made the right choice

[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:

[myrddin]

Just wanted to post an update to this thread:

I replaced the air bags and it seems to be fixed, after seeing the bubbles from the last test I felt pretty good about replacing them... While I was at it i also painted the frame and rear axle... looks better than new and no more sag.

Before:


After:


Thank you all for your help... I hope something in this post helps another Hummer buddy... I also hope I can return the favor sometime.

Humtech and Ed... you guys are too cool... Thanks.

[Hellz]

picys no worky

[myrddin]

Odd... I re-saved them... if that doesnt work I will try something else... I may post more tomorrow...

[myrddin]

Humtech, you post say?s that a loss of 1 mm overnight is the max acceptable drop... Is that realistic? I am wondering what I should expect, I parked my Hummer and plan on measuring the why you post says to measure... I am going to let it sit for an hour, then go out to get the measurement from the bump stop cup to the pad on the axle and then check it agn in the morning...

To be honest, I think it will settle in more than 1 mm.

Hope you have time to read this?
Thanks


Anyone else that has checked can you chime in as well?