[Richard]

It is confirmed that the aft air bag on the drive axle burped it's seal. The coach replicated the pancaking on the wheel in my driveway. It did exactly what @"bikestuff" 's coach did. Soapy water and the Infinicon positively identified the leak at the juncture of the air bag and the lower horn.

We tried getting the bag to reseal by airing up the coach all the way, but there is still a small leak.