Unit Maintenance Troubleshooting - Continued
TEST OR INSPECTION
ENGINE OVERHEATS ACCORDING TO ENGINE COOLANT TEMPERATURE GAGE
Step 1. Check coolant level.
Care should be taken when removing radiator cap. Steam or hot coolant under
pressure may cause injury to personnel.
Do not add coolant when engine is hot. Internal engine damage could result.
If coolant level is low, fill to proper level (para 2-35).
Inspect water pump drivebelt for looseness, absence, and worn out condition.
If belt deflects more than 3/4 in. (1.8 cm) or less than 1/2 in. (1.3 cm), adjust (para 2-41).
If belt is missing or worn out, install new belt (para 2-41).
Step 3. Inspect radiator, water pump, hoses and hose connections, and draincocks for leaks.
Tighten hose clamps and fittings.
Replace defective cooling system components.
Tighten or close draincocks.
Replace radiator or water pump if leaks are detected (para 2-35 and 2-50).
Step 4. Inspect fan for cracked and missing blades.
Replace fan if necessary (para 2-48).
Step 5. Check radiator for airflow obstructions.
Remove obstructions from front of radiator.
Step 6. Test thermostat for proper operation.
Replace thermostat if defective (para 2-45).
Step 7. Check aftercooler for obstructions.
If there is no coolant flow through aftercooler, remove aftercooler and clean aftercooler core (para 2-47).
Step 8. Check coolant filter assembly.
Replace filter if necessary (para 2-44).