1. Cooling system

2. Cooling System Components  Antifreeze/coolant  Thermostat  Water pump  Radiator  Radiator pressure cap  Expansion tank Hoses Water outlet Water jackets Cooling fans Temperature indicators

3. Cooling System Components (Cont’d)

4. 50/50

5. Premixed coolant

6. Cooling System Service  Pressure test the system for leaks.  Check coolant condition and strength using a hydrometer.  Check radiator cap for proper pressure.  Test thermostat for proper opening and closing temperatures.

7. Cooling System Service (Cont’d)  Check hoses for leaks and swelling.  Check the system with a voltmeter for electrochemical degradation.  Check water pump for bearing failure and leaks.  Check cooling fans and fan clutch for proper operation.

8. Common Causes of Water Pump Bearing Failure  A bent fan  A missing piece of fan blade  A cracked fan blade  Fan mounting surfaces that are not flush  A worn fan clutch

9. Water Pump

10. Fan

11. Clutch fan  Filled with a silicone fluid  Some have a thermostatic spring on the front of the clutch that is temp sensitive.  Visual and physical inspection.

12. Basic tests  The basic procedure for testing a vehicle’s cooling system includes inspecting components and testing for external and internal leaks.  Belt problems are easily discovered by visual inspection or by the sound of slippage.

13. Quick fix ?  To stop leak or not to stop leak. That is the question.  What else could go wrong here?

14. Thermostat Design

15. Radiator Cap

16. Hose Clamps  Worm gear clamp  Screw tower clamp  Spring clamp  Twin wire clamp  Rolled edge clamp  Heat shrink clamp

17. Don't Get Hosed!

18. Check the Belt

19. Smooth to Smooth Groove to Groove