Hi all, I just recently bought a '99 EB Expy with the air suspension. When I bought it it was badly out of alignment and needed brakes and tires.

I did the brakes myself, but had a shop do the alignment and tires. The day after the alignment I went out of town for a week and when I came back it looked like the drivers side rear was sagging. So I checked it with a tape measure and the rear bumper had almost a 2" difference from side to side. We played around with the suspension a little by moving the sensors around but it would never level itself out (side to side). We even let the rear bags deflate all the way down until the spare tire was resting on the track bar and then let 'em pump up but it was still sagging. Nothing we did could fix the sag.

This morning was the first chance I had to drive it any real distance and when I got to my destination I looked at the rear and it looked level. So I checked it with the tape measure and sure enough, it was within 1/4" on both sides. If anything it was a little lower on the passenger side this time.

Any ideas on what's going on here? I was thinking at first that the aligment shop may have screwed something up, because even though I told them 3 times that it had the air suspension, when I got the aligment sheet back it had the specs for that said "except air suspension" in big letters at the top.

 

I've read in my owners manual that if you are lifting the Expy's with air susupension off the ground be it on a hoist or even changing a tire that it is recommended to turn the suspension off. Maybe something like that could mess the heights up?

 

Yeah I had thought about that. Does anyone know exactly what it does if you leave the suspension turned on and lift it?

To be sure I had turned the suspension off before I dropped it off for tires. When the tech called me back to tell me the alignment adjustments were already at max. and they had to weld in different adjustments, I told him twice (and I called back once more just to make sure they knew) that it was an air suspension and that they need to turn it back on and let it come up to ride height before they aligned it. He said basically "oh yeah we deal with these air suspensions all the time, so we know what we're doing." But then I get the alignment spec sheet back and it says "except air suspension" so I'm not sure.

I hope it was just a one time thing. I'll have to look at it again when I get home, but just eyeballing it in the parking lot when I went to lunch it looked fine.

 

Mine sits unlevel from side to side also sometimes. Just enough that I can notice it from behind. I'm pretty picky so I'm looking close. Hopefully it's just a matter of the computer reseting itself. I would try maybe disconnecting the battery to reset everything.

 

Do you know how it figures out when it's level? while we were messing around with it we noticed that there is only one sensor on the rear axle, in the center near the diff. How does it know when it's level side to side? From what I can tell I can only see how it would know front to rear.

 

Thats a good question. I wonder if the one sensor is exactly centered with the rear end. In that case I would imagine, if you could, adjust the sensor from side to side but from what I can remember from seeing mine is that it is fixed in it's location.