Cooling system servicing (draining, flushing and refilling)
(every 60 months)
Warning: Wait until the engine is completely cool before beginning this procedure. Warning: Do not allow antifreeze to come in contact with your skin or painted surfaces of the vehicle. Rinse off spills immediately with plenty of water. Antifreeze is highly toxic if ingested. Never leave antifreeze lying around in an open container or in puddles on the floor;
children and pets are attracted by it’s sweet smell and may drink it. Check with local authorities about disposing of used antifreeze. Many communities have collection centers which will see that antifreeze is disposed of safely.
1. Periodically, the cooling system should be drained, flushed and refilled to replenish the antifreeze mixture and prevent formation of rust and corrosion, which can impair the performance of the cooling system and cause engine damage. When the cooling system is serviced, all hoses and the pressure cap should be checked and replaced if necessary.
Draining
2. Apply the parking brake and block the wheels. If the vehicle has just been driven, wait several hours to allow the engine to cool down before beginning this procedure.
3. Once the engine is completely cool, remove the radiator cap.
4. Move a large container under the radiator drain to catch the coolant. Attach a length of hose to the drain fitting to direct the coolant into the container, then open the drain fitting (a pair of pliers may be required to turn it) (see illustration).
32.4 The radiator drain fitting is located at a lower corner of the radiator
5. After the coolant stops flowing out of the radiator, close the drain fitting, move the container under the engine block drain plugs and allow the coolant in the block to drain (see illustration).
32.5 The block drain plugs are generally located about one to two inches above the oil pan – there is one on each side of the engine block
6. While the coolant is draining, check the condition of the radiator hoses, heater hoses and clamps (0, if necessary). Replace any damaged clamps or hoses.
7. Reinstall the block drain plugs and tighten them securely.
Flushing
8. Once the system has completely drained, remove the thermostat housing from the engine (see Cooling, heating and air conditioning systems), then reinstall the housing without the thermostat. This will allow the system to be thoroughly flushed.
9. Disconnect the upper hose from the radiator.
10. Place a garden hose in the upper radiator inlet and flush the system until the water runs clear at the upper radiator hose (see illustration).
32.10 With the thermostat removed, disconnect the upper radiator hose and flush the radiator and engine block with a garden hose
11. Severe cases of radiator contamination or clogging will require removing the radiator (see Cooling, heating and air conditioning systems) and reverse flushing it. This involves inserting the hose in the bottom radiator outlet to allow the clean water to run against the normal flow, draining out through the top. A radiator repair shop should be consulted if further cleaning or repair is necessary.
12. When the coolant is regularly drained and the system refilled with the correct coolant mixture there should be no need to employ chemical cleaners or descalers.
Refilling
13. Place the heater temperature control in the maximum heat position.
14. Slowly add new coolant (a 50/50 mixture of water and antifreeze) to the radiator until the level is up to the bottom of the filler neck.
15. Install the radiator cap and run the engine in a well-ventilated area until the thermostat opens (coolant will begin flowing through the radiator and the upper radiator hose will become hot).
16. Turn the engine off and let it cool.
17. Squeeze the upper radiator hose to expel air, then add more coolant mixture if necessary. Reinstall the radiator cap.
18. Start the engine, allow it to reach normal operating temperature and check for leaks. Also, set the heater and blower controls to the maximum setting and check to see that the heater output from the air ducts is warm. This is a good indication that all air has been purged from the cooling system.