[newell_0]

Sayed: when you ran this latest test did you leave the leveling system in an "on" setting that continued to actively attempt to keep the coach level? If so, you could have a leak on the left side air bag system (not necessarily the air bags themselves) that the leveling system attempts to rectify until it depletes the "supply" air.

A test for this would be to repeat the test you just did with the only change being to shut off the leveling system after bringing up the pressures and leveling the coach. Watch the rate of drop in the "supply" tank gauge. If my suspicions are confirmed, the left side will drop sooner than during the last test and the "supply" tank will leak down noticeably slower. If this turns out to be the case, the leak will be downstream from the rear six-pack including the fitting on the end of the six-pack.

If in this test the left side drops and the "supply" pressure drops as before then you know you have at least two leaks to find. Let us hope that is not the case as it makes life a bit more difficult and I like "easy".

Thanks for your suggestion!
No, I had the leveling off - have had everything that I can of that uses air turned off or not used like the entry and inside sliding doors.