Autoride shocks not holding air.

I purchased a 2009 Tahoe LTZ 6.2L with Z55 and Z82 suspension options. I am fairly mechanally inclined but I will admit that I do not understand this suspension at all.

The ride seems rough and the truck wanders from side to side especially when I hit bumps at highway speeds. Bumps seem to hit fairly hard.

I suspected something may be wrong with the suspension. The air pump comes on each time I start the truck and runs for 30 seconds or so and then turns off. I have not DTC’s and no warnings at all.

My question is should the shocks have air in them at all times? My rear shocks don’t appear to have any air in the rubber bladder at all... ever. I can squeeze them with my hand even after the pump has ran and shut off. I loaded down the rear with several hundred pounds and the pump comes on but still I can squeeze the rubber bladders with my hand like an empty balloon.

I took this to my Cheverolet service center and they said nothing was wrong. Also, I see a level sender on the front just like the rear. Are the front shocks air too?

I need help understanding if this is what is supposed be happening.

the air bladder should be holding air, you can do a very simple verification by just pulling off the nozzle connected to the shock, when you pull it off there should be a blast of air even if you are just parked and the pump has not ran. you should also be able to hear the pump release air just before it kicks on, then when it kicks on you should be able to visibly see the rear end lift up an inch or two as the pump is going. if it turns out they are bad and you want to replace them rockauto sells the Arnott (oem remanufactured) with a lifetime warranty they run about $140-150 each with a $50 core that gets refunded when the old ones are returned. the price is a fraction of a original gm plus you get lifetime warranty versus 1 year for oem.

**there is also a 5% off discount code for rockauto in the vendor section

Also to answer your question about the front...

NO the front does not have any air ride. The sensor and arm you see attached to the upper control arm is simply a sensor to tell the suspension control module what the road conditions are so that it can adjust the electronic valving inside the front struts for dampening.

The bladder on the rear shocks should be firm when you squeeze them. They tend to get holes in the portion that is rolled inward where you cannot see it until you remove the shock.

A spray bottle with some soapy water is a good tool to help find the leak, which you obviously have. Start by spraying the bladders while someone else turns the key on so you can be under the truck to watch for bubbles while the compressor is running. If the bladders are good spray all the air lines and fittings from the shocks back to the air compressor.

Thanks very much for the information. This explains how the system works and gets me comfortable enough to diagnose my issues. It also lets me know that not all GM service centers know what they are doing. They told me that it was normal for the air bladders to be completely empty of air sometimes.

Again, I really appreciate the help. I will diagnose my issues and let you know what I find.

Both rear shocks are leaking. Now I need to know why the air pump stopped when the shocks still needed air? I guess I will see if I can manipulate the leveling sensors to see if they start the pump or not.

The air pump is designed to turn off after so long, so it doesn't burn itself up. I also have an 09 LTZ with Z55 and when I bought it, it had about 135k with original suspension. My front shocks/struts weren't leaking, but were so worn that the computer kept the fronts fully engaged so it rode rough to say the least. I never got any codes, but as soon as I replaced them, it rides very nice and soaks up bumps. I replaced everything when I did mine.

Toby said:

Both rear shocks are leaking. Now I need to know why the air pump stopped when the shocks still needed air? I guess I will see if I can manipulate the leveling sensors to see if they start the pump or not.

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NO that wont do anything but screw the system up and cause codes, the pump only goes on for 30 seconds max then shuts off regardless of anything. nothing that you do will make the pump keep running unless you wired it straight to 12v then it would just run until it burnt out

your options are
1. replace the shocks w/oem or aftermarket air ride shocks
2. delete the air ride and go with standard shocks and resistors to prevent codes

I had to use standard shocks on my LTZ for a week, because of reasons I'm not going to mention... Made an expensive rookie mistake and that's the short story.. anyhow, the standard shocks suck so bad in my opinion because the Z55 works with everything including stabilatrak. When I had my week of standard shocks, the front end sunk in corners instead of how the electronic front shocks energize during hard cornering. A lot of guys on here delete Z55, but honestly in my opinion, just rebuild the factory stuff. I am so glad I did because after installing all new stuff, plus eibach sway bars, my Tahoe handles really well.

Mikeyss - Do you mind sharing what brand you used for the OEM rebuild? I'm searching for parts on my 08 and since I plan to keep it a while I'm ok with spending $$ for the full good quality ride.