Gil,
I checked the coach and noticed it was leaning to the left for the first time ever. I started the engine and let it run for 5 minutes, then turned it off—no noticeable leak. When I turned the key on, the hissing started. I inspected both ride adjustment valves, but neither seemed to be leaking. The air leak is quite pronounced, coming from somewhere between the two sets of air bags (port and starboard), closer to the port side, where the coach was leaning.
It’s like there’s an open valve, causing a significant amount of air to escape. Tomorrow, I’m taking the coach to a truck shop with a long pit, so I’ll be able to see exactly where the air is coming from. It’s so pronounced that it should be quite evident.
If you have any additional thoughts or tips for my search, I’d appreciate them. For now, I’ll have to wait until tomorrow to get a better look. I don’t think the air bags themselves are causing the problem, even though the air pressure eventually decreased on one side for the first time.
By the way, you can travel 200 miles south from here and still be in Texas! I was talking to some folks from Tampa today and have a connection there; we meet in Sarasota sometimes. If we meet up, I’ll bring the coach and we might get together.
I’ll keep you updated on the leak mystery. Thanks again for your help!
Best, Pres