Probable Causes
- Parameters
- Low coolant level
- Insufficient flow of air or coolant through the radiator
- Coolant leak
- Faulty engine cooling fan (if equipped)
- Faulty pressure relief valve
- Faulty temperature regulator
- Faulty jacket water pump
- Excessive load
Recommended Actions
Parameters
Verify that the system parameters are programmed to the correct values. The system parameters can be adjusted on Caterpillar Electronic Technician (ET). Refer to Troubleshooting, "System Configuration Parameters" for the correct values.
Low Coolant Level
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Pressurized System: Hot coolant can cause serious burns. To open the cooling system filler cap, stop the engine and wait until the cooling system components are cool. Loosen the cooling system pressure cap slowly in order to relieve the pressure. |
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Inspect the coolant level. If necessary, add coolant.
Insufficient Flow of Air or Coolant Through the Radiator
Check the cooling fins on the radiator for dirt and/or for debris. Remove the dirt and/or debris.
- Check the cooling fins on the radiator for damage. Refer to the Systems Operation/Testing and Adjusting manual for instructions for testing and inspecting the cooling system.
- Check the radiator for internal blockage. Check the temperature difference between the top and the bottom of the radiator.
Coolant Leak
Check the cooling system for leaks.
- Inspect the coolant for presence of bubbles.
- Check the cooling system for combustion gases. Inspect the cylinder liners for cracks.
Faulty Engine Cooling Fan (if equipped)
Check for proper operation of the cooling fan. Check the fan drive belts for correct tension. Check applicable drive belts, pumps, speed sensors and/or control solenoids for proper operation.
Faulty Pressure Relief Valve
Check operation of the pressure relief valve and the radiator cap. If necessary, clean the pressure relief valve and/or the radiator cap. Check that the seating surface of the valve is clean and undamaged. If necessary, install new parts.
Faulty Temperature Regulator
Check the water temperature regulators for correct operation.
Faulty Jacket Water Coolant Pump
Inspect the impeller vanes at the jacket water pump for damage and/or for erosion. Repair impeller vanes and/or replace the impeller vanes.
Excessive Load
Check that the engine is not loaded beyond design.