[dkarb]

To be clear, in my post on this thread I wrote about "leveling valves".  By leveling valves I'm talking about the 3 actual leveling valves, one in the front and 2 in the rear.  After correcting the wiring, my coach was doing the same thing that Clarke described.  (Dropping down on one side from ride height and supply air going to zero.) If your coach does start doing that again after making sure there are no major air leaks anywhere else, and as the right side is dropping down from ride height there is air exhausting from the right rear leveling valve, I would think you have a right leveling valve going out (and therefore only working properly sporadically) due to age.  Richard or others please correct me if I'm wrong.