Typerod

Hi all, so I brought my 07 Tahoe LTZ to the transmission shop. I've been having rear differential whining and a scrubbing noise. Turns out the one of the carrier bearings was bad. But as they had my car up on the lift, they mentioned that the air struts are bad. He said they are supposed to have air in them. I gave the rubber a squeeze and no air was in them and I just felt structure inside the air strut. Is there supposed to be in them at all times? The car was up on the lift, wheels were hanging down.

Maybe my understanding of them has been wrong all this time. So I said my compressor still works, I hear it kick on after the vehicle starts. But I said I don't think there is a leak b/c the compressor would continue to run, until it burned itself out. Although my compressor is very noisy these days, much louder than it used to be, it still kicks on after the start of the engine like normal, and I never hear kick on unless we are fully loaded in the back.

Can someone please explain the air ride system to me? If my struts are really flat, wouldn't the ride be harsh and jarring? The shop seems trustworthy, they have great reviews on google and yelp. I feel confident about them working on my rear differential. So I don't think they are just fishing for work.

Thanks in advance!

Scotiapilot

The air bag is for load leveling, if you had a ton of weight on it then the ride height sensors would activate the pump and lift your car. SO much can go wrong, the sensors could be miss adjusted too. Your pump starts to check the system. The shock it surrounds is a shock absorber.


It sond like your system is working correctly, the only way to acutally acitivate the pump is to put weigh on the rear and see if the pump will level your car.


It sound like the mech knows nothing about this system. Are you at a Chevy dealer?


If the axle was being extended then the bag would of course feel flat as there is no compression on the air bag.


Think of it like a half full balloon. Squeeze the balloon and it compresses the air etc.

Typerod

Thanks for your response! I was at an independent transmission shop. He just kept saying they should be filled with air. But I was thinking just as you mentioned, the car is lifted up and it supported by its jacking points. I didn't think the air strut should be filled any, and it wasn't. As soon as I touched the rubber part I was touching the internal damper.

Thanks again, I feel a bit better now! lol!

tech2

spray a dish soap solution on the air bag part of the shock and inspect after 5 minutes. if the bags are leaking, you will see bubbles forming.


the system never goes above 50psi and may have as low as 10psi

cleveland63b

Raising the vehicle by the frame will help, a lot of times if they do leak its the area that gets folded up when fully loaded. If your compressor doesn't run a lot its not likely you have a leak but there are other circumstances

Typerod

Thanks guys for your replies! If I did have a leak either or both air bags, wouldn't the compressor just run and run till it burned itself out? Or is it possible there is a leak but the compressor will turn off anyway?

I don't ever hear the compressor run after it does its intial turn on, UNLESS all four of my family members (myself included) are in the car and/or we have the rear cargo area loaded with luggage or groceries. And it doesn't ever run for a very long time, it will eventually shut off, I guess when it reaches is desired height.

{tpc}

Not necessarily. Without a load, it may be at the right height to begin with. Its not like the rear end deflates when you park for the night. It can and it might, but its not a thing that just happens. So if its at the right height, the compressor will come on to verify the system is working, and it can vent out the air after its system check. In your case, the system doesn't have to vent out, because it may already be letting the air out.

When I bought my truck used, it acted normal, did the initial check, I had no lights or anything. Since I use my truck for towing, and I was about to leave for a long trip, I decided to buy refurbished arnott rear shocks, to keep the magnetic ride as well as the load leveling feature. It was only during the replacement, that I found out my rear bags were completely rotted all the way around.

Let me suggest that unless you plan on buying the oem fronts to keep the magnetic ride up there, I wouldn't bother with it in the rear. I didn't realize that the fronts would be so expensive so when I replaced them I ended up having them put on whatever they would replace the fronts with on a LT, and then cutting off the connector and attaching a load resistor to the harness to fool the computer into thinking the shocks with the magnetic fluid were there.

If I was doing it again, I'd keep the load leveling but ditch the rest of the magnetic stuff, and go with the arnott bilstein kit all the way around.

Typerod

Thanks for the replay. I didn't know that the 07 Tahoes had the option for a magnetic suspension. I thought I just had a normal fluid strut up front and the rear air suspension in the rear.

I remember people saying their compressors burning out due to leaks in their rear air bags.

I'm going to get under my Tahoe today and take a closer look at the rear struts.

{tpc}

You have the LTZ so I would expect it to have the magnetic fluid filled shocks. Look at your fronts, there should be a connector on the top of them. Thats what controls the fluid inside.

My fronts didn't take long to start pissing fluid everywhere, but I am sure they were original and never replaced. Since I bought used, it was expected. Somewhere along the way I misread the cost to replace them. The rears also have fluid in them as well as the air bags.

Typerod

I just checked underneath my Tahoe, the rears did not have any air in them at all. I'll check them this weekend we are going on a trip and will be packed up with luggage etc. I have ~206K on the car, and it is still riding on the original struts. I'll check the fronts tomorrow and look for the connector you mentioned.