Cooling system servicing (draining, flushing and refilling)
Warning: The engine must be completely cool before beginning this procedure.
Warning: Do not allow engine coolant (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 its sweet smell and may drink it. Check with local authorities on disposing of used antifreeze. Many communities have collection centers which will see that antifreeze is disposed of safely. Antifreeze is flammable under certain conditions — be sure to read the precautions on the container.
Note: Non-toxic antifreeze is available at most auto parts stores. Although the antifreeze is non-toxic when fresh, proper disposal is still required.
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 radiator 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 expansion tank cap.
4. Move a large container under the radiator drain to catch the coolant. Attach a hose to the drain fitting to direct the coolant into the container (some models are already equipped with a hose), then open the drain fitting (a pair of pliers may be required to turn it) (see illustration).
i. 4 You will have to remove the forward under-vehicle splash shield for access to the radiator drain fitting located at the bottom left corner of the radiator — before opening the valve, push a length of hose onto the plastic fitting to prevent the coolant from splashing
5. While the coolant is draining, check the condition of the radiator hoses, heater hoses and clamps (refer to Cooling system check if necessary). Replace any damaged clamps or hoses.
Flushing
6. Close the radiator drain valve.
7. Fill the cooling system with clean water, following the Refilling procedure (see Step 13).
8. Start the engine and allow it to reach normal operating temperature, then rev up the engine a few times.
9. Turn the engine off and allow it to cool completely, then drain the system as described earlier.
10. Repeat Steps 7 through 9 until the water being drained is free of contaminants.
11. In severe cases of contamination or clogging of the radiator, remove the radiator (see Cooling, heating and air conditioning systems) and have a radiator repair facility clean and repair it if necessary.
12. Many deposits can be removed by the chemical action of a cleaner available at auto parts stores. Follow the procedure outlined in the manufacturer’s instructions.
Note: When the coolant is regularly drained and the system refilled with the correct antifreeze/water mixture, there should be no need to use chemical cleaners or descales.
Refilling
13. Close and tighten the radiator drain. Remove the drain hose.
14. Place the heater temperature control in the maximum heat position.
15. Slowly add new coolant (see this Chapter’s Specifications for the proper mixture of water and antifreeze) to the expansion tank until it’s full. Add coolant to the reservoir up to the lower mark.
16. Squeeze the upper and lower radiator hoses to expel air, then recheck the coolant level, adding as necessary.
17. Install the radiator cap/expansion tank cap and run the engine in a well-ventilated area at approximately 2000 rpm until the engine cooling fan comes on.
Caution: If the coolant level drops below the Low line, allow the engine to cool completely, then add coolant.
18. Turn the engine off and let it cool completely. Add more coolant mixture to bring the level back up between the Low and Full lines on the expansion tank.
19. Squeeze the upper radiator hose to expel air, then add more coolant mixture if necessary. Reinstall the radiator cap/expansion tank cap.
20. Start the engine, allow it to reach normal operating temperature and check for leaks.