B3.9 and B5.9 Series Engines
Troubleshooting Symptoms Charts
Section TS - Troubleshooting Symptoms
Air Compressor Will Not Stop Pumping
This is symptom tree T010.
Block the vehicle wheels and check the air
system for leaks with spring brakes applied
and released. Check for leaks from the air
Air system leaks
compressor gaskets and the air system hoses,
fittings, and valves. Refer to Procedure 012-019
and the OEM service manual.
Check the air governor for correct operation.
Make sure the air governor is located less than
2 feet from the air compressor. Refer to the
ir governor is malfunctioning
Master Repair Manual, Holset Air Compres-
sors, Bulletin No. 3666121.
Check the unloader valve and unloader body
seal. Refer to the Master Repair Manual,
nloader valve is malfunctioning
ir governor signal line or actuator line is
Inspect the signal line and actuator line. Refer
to the OEM service manual.
Check the operation of check valves, alcohol
ir system component is malfunctioning
installed air system components. Refer to the
OEM service manual.
Inspect the air compressor intake and exhaust
valve assemblies. Refer to the Master Repair
ir compressor intake or exhaust valve leaks