[MTD]

You could disconnect the air line from the six pack to the air bag on that side, and pressurize it with an external compressor. That may help you find your leak without having to run the engine.

don’t discount the air bag leaking, because of the internal design, it if is leaking on the bottom of the bag, you will not find it with soapy water.

 
Thank you for the reply, Richard

I learned what a six pack is, after a forum search. This coach has two, right next to each other. There are some small air leaks there and with luck once we fix those the leaning problem will be solved.

The leaning problem didn't show up until we replaced the driver side height control valve. Before that both sides leaked and the coach settled evenly.

It's good to know that leaks on the bottom of an air bag won't show up with soap solution - I'll try and remember that for future troubleshooting adventures. Would an electronic leak detector pick up those leaks?  Or is it a matter finding and fixing all other leaks and if the air bag circuit still won't hold air pressure for a few hours, then replacing the air bag?