Cooling System: Service and Repair

Cooling System Typical:

1. Remove radiator cap when engine is cool by:
a. Slowly rotating cap counterclockwise to detent. Do not press down while rotating.
b. Wait until any residual pressure (indicated by a hissing sound) is relieved.
c. After all pressure has been relieved, press down on cap while continuing to rotate counterclockwise.

CAUTION: To avoid the danger of being burned, do not remove radiator cap while engine and radiator are still hot. Scalding fluid and steam may be blown out under pressure, causing serious bodily injury.

2. Remove thermostat by using the wire handle to lift it out of the housing. Replace cap.
3. Open radiator drain valve, engine drain plug and coolant pipe plugs.
4. Close valve. Reinstall engine block drain plug and coolant pipe plugs.
5. Run engine. Drain and refill the system, as described in Steps 1, 3 and 4, a sufficient number of times until the drained liquid is nearly colorless.
6. Allow system to drain completely and then close radiator drain valve tightly, and reinstall block and coolant pipe drain plugs.
7. Remove recovery cap leaving hoses in place. Remove coolant recovery tank and empty of fluid. Flush tank with clean water, drain and reinstall.
8. Add enough water and ethylene glycol antifreeze to provide the required cooling, freezing and corrosion protection. Use a solution that is at least 50 percent antifreeze, but no more than 70 percent antifreeze. With the engine off, remove the radiator cap add coolant through the thermostat housing until the coolant reaches the spill point of the radiator neck. Reinstall the radiator and thermostat housing caps. (Do not install thermostat at this time). Install 3.2 qts. (3 liters) of coolant into the coolant reservoir.
9. Run engine for 3 minutes. Accelerate engine to a fast idle for 15-20 seconds. Turn the engine off. Remove the thermostat housing fill cap.
a. Turn the cap slowly to the left until it reaches a "stop". Do not press down while turning the cap.
b. Wait until any remaining pressure (indicated by a hissing sound) is relieved, then press down on the cap and continue turning it to the left.
10. Add coolant to the thermostat housing until it reaches the housing cap seat. Reinstall the thermostat and cap making sure that the arrows on the cap line up with the water inlet hose on the thermostat housing.
11. When the engine has cycled through a complete warm-up and cool, the coolant in the reservoir should be adjusted to a level between the add and full lines. It is the owner's reponsibility to keep the freeze protection at a level proportionate with the temperatures which may occur in the area of vehicle operation.
a. Maintain cooling system freeze protection at -34~F (0~C) to ensure protection against corrosion and loss of coolant from boiling, even though freezing temperatures are not expected.
b. Add ethylene glycol base coolant that meets GM specifications when coolant additions are required because of coolant loss, or to provide additional protection against freezing at temperatures lower than -34~F (0~C).
c. Alcohol, methanol base coolants, or plain water are not recommended at any time.