Poor brake maintenance can also contribute to the problem. Brake imbalance. air pressure to some brakes than others. Restriction in the compressor inlet pipe. Compressor cylinder head gasket leaking. Restriction in the compressor delivery pipe. Unloader piston in the compressor head sticking. Unloader valve cut-out pressure set too low. Blocked air dryer cartridge.

One of the most important symptoms to look for is noisy brakes. Braking imbalance can also indicate problems with the hoses and fittings running between the brake chambers and valves. Drums often become glazed as the result of overheating during periods of intense use. Air pressure gets too low. Vibration coming from the brakes.