B3.9 and B5.9 Series Engines
Troubleshooting Symptoms Charts
Section TS - Troubleshooting Symptoms
Air Compressor Air Pressure Rises Slowly
This is symptom tree T004.
Replace the air compressor air cleaner (if
installed). Check the air intake piping. Check
engine air intake restriction if the air compres-
Air intake system restriction to air compressor
sor inlet is plumbed to the vehicle or equip-
ment intake system. Refer to Procedure
Block the vehicle wheels and check the air
system for leaks with spring brakes applied
and released. Check for leaks from the air
compressor gaskets and the air system hoses,
ir system leaks
fittings, and valves. Refer to the Master Repair
3666121 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-
sor, Bulletin No. 3666121.
Check for carbon buildup. Replace the air
compressor discharge line if necessary. Check
arbon buildup is excessive in the air dis-
the turbocharger for oil leaks. Refer to Proce-
charge line, check valve, or cylinder head
Check the operation of check valves, alcohol
ir system component is malfunctioning
installed air system components. Refer to the
OEM service manual.
Check the unloader valve and unloader body
nloader valve is malfunctioning
seal. Refer to the Master Repair Manual,
Inspect the air compressor intake and exhaust
valve assemblies. Refer to the Master Repair
ir compressor intake or exhaust valve leaks