Air Brake Help???

[talk2cfs]

I have a 89 Ford B700 with air brakes. Ive never had any problems with the braking system until a buddy of mine said he tried to move the bus and didnt wait for the air presure to build up and could release the parking park and still tried to move the bus by putting it into gear for a little bit and then decided to call me for help. I told him you cant move it or try until the brake system warning light and buzzer stops and you then can release the parking brake. Hestopped what he was doing and gave up . A couple days later when they were ready to move it again, the air gauge wouldnt move and the system just keep buzzing and would pump up. I have checked the compresor and looked for leaks and still cant figure out what went wrong. Anyone else have this problem or know what possible could be the problem? Any help would be great. Thanks/

[frank-id]

Make sure the engine will run. Remove the air compressor discharge air line. Start the engine. Check for any air pressure. If no air, bus can be moved by connecting a portable electric or gas powered compressor to the air line removed. A large bottle of nitrogen with a 100psi regulator will fill the bus tanks OK too. Some times the air problem is as simple as the air compressor governor is broken. The governor is about $50 rebuilt or $25 at a salvage place or rebuild shop. It only needs to have a few bolts r&r to change the governor. Bad governor = no air. Frank