Never had the problem. We have always been able to use the "dump air" function of the leveling system.
I would try to drain the aux tank using one of the quick connects for an air hose. One front one back.
Perhaps then air would migrate out of the bags?
1995 38' CC Magna #5280
C8.3L 300hp Cummins, 31,000lbs
Gillig Bus Chassis