air pressure problems

First off I am not familiar with your coach however since it has an air system I imagine it has air brakes. In my 43+ years driving truck and 3 to 4 million miles 60# of air pressure won't release parking brakes. I would guess air governor stuck is your problem. In my experience the governor has been mounted on top of the compressor. Cylinder shape about 1.5" x 4" and has a rubber cap on one end. Try tapping that with a hammer while engine and compressor is running. Good luck, Don