air pressure problems

[EPeterman]

parked in tx for winter started up discovery 275 cummins and air fails to build over 60 after 15min any ideas?

[EPeterman]

air lowering knob on dash took care of problem thanks tonew view of tunnel vision I don't remember the problem before. thanks fir response it helped me..

[diplomatdon]

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

[Bill_Satellite]

Are you hearing any air leaks outside? Are you running the engine up to 1000 RPM or higher? What more can you tell us that you have done in the way of trouble-shooting? I am hopeful that Doug's answer solves your problem.

[dougrainer]

drive the unit forward about 20 feet and then stab the brakes. That usually frees up the Freightliner air bag arms. Doug

[Ivylog]

Rev the engine up and start trying everything...brakes, brake release and even air leveling. Hopefully something will seal up and the pressure will build. If not shut engine off and get out and listen for the leak.

[azdryheat]

Do you have a valve that dumps the air that might still be on?