Air suspension issues (or "#%$@!" again!)

[mdoyle]

I've got a 2003 H2, adventure pkg with air suspension.

Here's the problem that defies logic, about 75% of the time after the truck is parked for a few minutes, the air suspension will be totally lowered. When I start it, it returns to ride height.

The first reaction is there is a leak, but that doesn't explain why it isn't consistantly flat. It also seems the suspension is constantly changing, I hear it cycling at stop lights on flat ground sometimes.

I've gotten no warning lights and I always wait a minute or two for it to inflate before driving but the problem seems to be worsening and lately has affected ride height on the highway.

After searching this site I didn't see any similar problems and I'd rather fix it myself. My first guesses are either of the position sensors or a relief valve.

Has anyone had a similar problem? My concern is the dealer might be inclined to replace more than necessary.