AIR BRAKES - GENERAL INFORMATION DIAGNOSIS GUIDES (Cont’d.) CONDITION POSSIBLE CAUSE RESOLUTION Air Pressure Rises Faulty air gauge (registering Repair or replace as necessary Above Normal incorrectly) Governor out of adjustment Adjust as necessary Faulty governor and safety valve Repair or replace as necessary Frozen line to governor Thaw and drain condensation Restriction in line between Repair or replace as necessary governor and compressor restricted unloading valve Too much clearance at Adjustor repair as necessary compressor unloader valves or compressor unloading mechanism stuck in closed position Air Pressure Drops Quickly Leaking brake valve Repair or replace as necessary With Engine Stopped and Leaking tubing or hoses Repair or replace as necessary Brakes Released Excessive leakage elsewhere in Check air supply system Repair air brake supply system or replace components as necessary Parking brake chamber leaking Replace diaphragm Air Pressure Drops Quickly ’ Leaking brake chamber, actuator Repair or replace as necessary With Engine Stopped and or brake cylinder Brakes Fully Applied Leaking brake valve Repair or replace as necessary Leaking tubing or hose line Replace as necessary Compressor Knocks Loose drive pulley Repair or replace as necessary Continuously or Intermittently Backlash in drive gears or drive Repair or replace as necessary coupling Worn or burnt out bearings Repair or replace as necessary Excessive carbon deposits in Clean or repair as necessary compressor cylinder head Safety Valve "Blows Off" Air pressure in air brake system Check unloader mechanism above normal Repair or replace as necessary Faulty governor Check governor function Frozen line to governor Thaw and drain condensation Excessive Oil in Brake System Compressor passing excessive Repair or replace compressor as oil necessary Compressor air strainer restricted Repair or replace as necessary Excessive engine oil pressure Check and adjust engine oil pressure as necessary Back pressure from engine Check and repair/adjust as crankcase necessary Excessive oil in compressor Drain excess from compressor crankcase CTS-4154Y - Page 25