[Dmatz]

Did you dump the air on the engine side if the system? Thus can be done by pumping your break pedal with the engine off. It sure sounds like a check valve that is leaking. If you dump the air on your bags, the chassis side and dump your aux jar and it's gone then I suspect a check valve. I would bring aux air back on first then chassis air then bags. Had a similar issue with a bluebird I had.