[Richard]

One other thing to consider which has bitten at least two other owners is this. The air bags in the rear are very close to being undersized, which means they take a full 120 psi to raise the coach. It shows up on the left rear because this is the heaviest corner.

It would be a quick sanity check to do one of two things to eliminate this potential factor. One, put a quick connnect fitting on a good gauge and stick it in the port in the rear. Two, hook it back up to shop air and turn the regulator up to 125 psi.

I would take a Quick Look at this before I investigated valves and bags.