Engine is cold

Allow the engine to warm to operating temperature. If the engine will not reach operating temperature, refer to the Coolant Temperature Below Normal troubleshooting symptom tree in Section TS.

Lubricating oil pressure is below specification

Check the oil pressure. If the pressure is low, Refer to Procedure 007-028 in Section 7.

Air in the lubricating oil system

Check the oil level. If the level is high, check for a cracked oil suction tube. Refer to Procedure 007-025 in Section 7.

Engine brake housing oil plug is missing or loose

Check the outside of the brake housing for oil leaks and missing or loose plugs. Replace the plugs if necessary.

Clutch switch is malfunctioning

Check the clutch switch adjustment and the clutch switch circuit. Refer to the OEM service manual.

Engine brake throttle switch is malfunctioning

Check the engine brake throttle switch (fuel pump switch ).

Engine brake adjustment is not correct

Adjust the engine brakes. Refer to Procedure 020-024 in Section 20.

Solenoid valve o-ring seals are leaking

Remove the solenoid valve and inspect the top and bottom o-rings. Replace the o-rings if necessary. Refer to the OEM service manual.

Solenoid valve filter screen is covered with debris

Remove the solenoid valve and clean or replace the screen. Refer to Procedure 020-024 in Section 20

Outer control valve spring is broken or control valve is sticking

Inspect the outer control valve springs and control valve Refer to Procedure 020-024 in Section 20.

Master piston is stuck

Check the master piston for freedom of movement. Replace the master piston if necessary. Refer to Procedure 020-024 in Section 20.