MBE 4000 DDEC VI Troubleshooting – Section 14.3 Faulty Pressure Control Cap

Section 14.3
Faulty Pressure Control Cap

To determine if a faulty pressure control cap is causing high engine coolant temperature, perform coolant pressure control cap tests.‪

1. If the cooling system pressure is less than or equal to 62 kPa (9 psi), check the coolant hoses; refer to "14.4 Defective Coolant Hoses" .
2. If the cooling system pressure is greater than 62 kPa (9 psi), refer to "14.3.1 Pressure Control Cap Resolution" .

Section 14.3.1
Pressure Control Cap Resolution

Perform the following steps to resolve faulty pressure control cap:‪

1. Remove and replace pressure control cap; refer to OEM guidelines.
2. Install a new pressure control cap; refer to OEM guidelines.
3. Verify pressure control cap repair; refer to "14.3.1.1 Test Engine with Replaced Pressure Control Cap" .

Section 14.3.1.1
Test Engine with Replaced Pressure Control Cap

Perform the following to determine if exterior radiator repair resolved high engine coolant temperature:‪

PERSONAL INJURY ‪
To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked.‪

1. Start and run the engine.
2. Run the engine through its operating range with no-load for approximately five minutes, allowing the engine coolant to reach normal operating range.
   1. If the engine coolant temperature is normal, no further troubleshooting is required. Shut down the engine.
   2. If the engine coolant temperature is not normal, shut down the engine. Check coolant hoses; refer to "14.4 Defective Coolant Hoses" .