TM10-3930-660-20 Table 2-3. Mechanical   Troubleshooting   (Cont’d) MALFUNCTION TEST OR INSPECTION CORRECTIVE  ACTION Step 6. Check for collapsed radiator hose. Inspect radiator hoses and replace if required, para. 7-5. Step 7. Check  for  malfunctioning  thermostat,  temperature  sender,  or  gauge. Replace thermostat, gauge and/or temperature sender as necessary, para. 7-4, 8-7 and 8-37. Step 8. Check for malfunctioning water pump. Replace if necessary para. 7-6. Step 9. Check for plugged cooling passages in the cooling system. Flush the engine cooling system and fill with cleaning solution, and fill cooling system with coolant, para. 7-4. Step 10 Check for overloaded engine. Verify that the engine load rating is not being exceeded, para. 1-12. 22. COOLANT TEMPERATURE  BELOW  NORMAL Step 1. Check for incorrect thermostat or faulty thermostat. Test thermostat. Replace thermostat if required, para. 7-4. Step 2. Check temperature sender or gauge for malfunctions. Replace gauge and/or temperature sender if necessary, para. 8-7 and 8-37. Step 3. Check if coolant is flowing by temperature sensor. Flush the engine cooling system with cleaning solution and fill cooling system with coolant, para. 7-4. 23. COOLANT LOSS Step 1. Check for radiator or cab heater leaking. a. Inspect the radiator and cab heater hoses and connections for leaks, para. 7-5 and 17-10. 2-38