Hello,
You mentioned your old AS unit is still working?
I think the elek AS module on mine is shot.. Would you think about parting with your old module?
Please let me know.
Thanks.

 

Oh, man... terrible. Sorry, I dont have it. My build went long and difficult and I ended up having the shop junk the old frame without taking the time to pull any useful stuff. Im really regretting that. Ive thought of a half dozen things I should have kept. Hindsight can really gnaw on you. Sorry.

 

When I bought my first H2, the owner mentioned that he had specifically purchased an H2 without the air suspension. I thought to myself... interesting, ok... crazy... air suspension is awesome... had it on my Tahoe. Little did I know... then I bought my second H2 with air suspension... it is great until it is not...

Thought I would add my recent journey. I have the dual compressor on my 2008 H2, part number 20803372. I don't drive it often, and I noticed that my H2 began to loose air over several weeks, and then dutifully re-inflate. While it always reinflated, in the back of your mind you are always wondering when will it NOT reinflate? On a trail? In the middle of a roadtrip with the whole family? So began the process of fixing it.

After replacing air bags, lots of bubbly soap testing, and observation by my local dealer... it appeared that the level control solenoid was leaking. It appears that this very crucial component had an invisible crack somewhere. After significant hunting, a replacement for the valve could not be found. My question... why is such a critical part made of plastic???

Now, I don't have the confidence to do this myself like you guys, so I hunted for someone else who already had it figured out...

• Westar used to make replacement air compressors. The direct replacement, Westar CD-7740, is no longer manufactured. When I called they knew exactly what I was looking for, so they must get a lot of calls. The way I recall it is the guy on the phone laughed and said yeah, wish we could get you one but they aren't available.
• I called Rebuid Master Tech, who used to remanufacture these, and they indicated they have no plans to continue to do so and were not in the business of taking mine and remanufacturing it.
• There is one company on the web that says they will rebuild your suspension module. Invasion Auto Products in LA. I gave them a call, and they said this could repair it... but it did not sound like @finall was on the other end of the line ready to go make my air compressor work. Now maybe they know what they are doing, but I did not leave that call with the confidence that I could ship off this critical and rare part, and hope for the best. 2008-09 Hummer H2 Suspension Pump CTIS 25964200

So I sent the H2 to Predator take a look at the air compressor and fix a bunch of other issues. They pulled apart the air suspension compressor, looked up manufacturer parts and diagrams and custom built a new part. I think it is amazing what these guys can do. It is undergoing testing now, but these guys had the confidence they could fix it.

Here is the defective part...


Here is what they built. Being tested as we speak...

 

That's unfortunate. Well thanks anyways, it was worth a shot. Glad everything worked out okay with the frame swap.

 

I am the same way. I like the air suspension and a bit hesitant to switch over to coil springs. Not sure how much difference it will make in the ride. One thing forsure is, with coils it would be more reliable.
Mine was holding the air fine. Then all of a sudden, I would be out somewhere and the rear would completely drop out of no where. I took it to a mechanic awhile back and they mentioned that the module on the side of the air suspension unit was bad. They were able to somehow get it back to ride height using the tech 2 scannner and it lasted for probably another 6 months and was working fine during that time. Now a couple weeks ago I was the same thing happened. Trying to find that module has been a nightmare, and the used ones I did find... well let's say, I may as well take out a second mortgage to afford it. Kinda ridiculous what everyone was charging for a used module when GM was probably buying them for less than $100 bucks. Hoping one day to find one for a reasonable price since I am not even 100% sure if I change that, it will solve the issue. For now I have the bags hooked up to some schrader valves that I can fill with an air compressor. Atleast I can still use the vehicle this way until I can find a fix.
Good news to hear yours was able to be saved.

 

MaximusDecimus been following your posts.

Not sure or your ECU P/No, but the 05 twin units came with 10363984 now superseded or interchangeable with 89060585 in case you are still looking.

For the rear to drop suddenly, electronically three valves have to energize simultaneously:-

1. Left Inlet valve
2. Right Inlet valve
3. Exhaust Valve

Given the module's level of sophistication this scenario seems unlikely, with a faulty PCB or component anything is possible.

A corrupted Serial Bus cause by some aftermarket equipment is a possibility

A voltage spike hitting the ECU, this happened to me whilst using a smart charger to boost the battery in-vehicle.

It's unlikely to be an air component, however at the end of the inlet valve is a pressure transducer with an O-Ring (it's the connector just touching the poly bag in your pic) If this was to suddenly leak under pressure then both bags would dump, it can be removed and worth a check.

It could be a fault in the 24-Way connector, my AS relay stopped working and as I checked it a wire camel out, it's pin was also badly corroded. A sudden loss of power or intermittent power might cause the ECU to misbehave, so it's worth giving the 24-Way a good inspection and a little tug on each wire in case any have fractured with vibration.

 

@VBLocal89 AND... if you don't plan on using that dual compressor... and it is model 20803372... I am a buyer...