RAIL-GUIDE 1246525 - Caterpillar

Engine And Cooling System Heat Problems
The following conditions indicate that a heat problem exists.
Hot coolant is released through the pressure cap during the normal operation of the engine. Hot coolant can also be released when the engine is stopped.
Hot coolant is released from the coolant system but not through the pressure cap during normal operation of the engine. Hot coolant can also be released when the engine is stopped.
Coolant must be added frequently to the cooling system. The coolant is not released through the pressure cap or through an outside leak.
If any of the conditions in Step 1 exist, perform the following procedures:
Run the engine at medium idle, which is approximately 1200 rpm, for 3 minutes after the high idle shuts off. Running the engine at medium idle will allow the engine to cool before the engine is stopped.
Inspect the poly v-belt for contamination, wear, or damage as this may affect the fan speed hence the efficiency of the cooling system. If necessary, replace the poly v-belt. Refer to Disassembly and Assembly Manual, "Alternator Belt - Remove and Install" for the correct procedure.
Refer to "Visual Inspection Of The Cooling System" in order to determine if a leak exists in the cooling system.
Refer to "Testing The Radiator And Cooling System For Leaks" procedures.
If the coolant does not flow through the radiator and through other components of the cooling system, perform the following procedures.
Perform the "Testing The Water Temperature Regulator " procedures.
Clean the radiator and other components with hot water or steam at low pressure. Detergent in the water may also be used. Compressed air may be used to remove materials from the cooling system. Identify the cause of the restriction before you choose the method for cleaning.
Straighten any fins of the radiator if the fins are bent.
Check the high idle of the engine. The engine may overheat if the high idle rpm is set too high.