Coolant: Service and Repair

Draining and Refilling The Cooling System

Caution: To avoid the danger of being burned, do not remove the radiator cap while the engine and radiator are still hot. Scalding fluid and steam will be blown out under pressure.

1. Remove the radiator cap.
- Turn the cap slowly counterclockwise until it reaches the "stop." Do not press down while turning the cap.
- Wait until any remaining pressure (indicated by a hissing sound) is relieved.
- After all hissing ceases press down on the cap and continue to rotate the cap counterclockwise.
2. Open the radiator drain cock.
3. Remove the cylinder block drain plugs. One plug is located on each side of the cylinder block. Remove the cooling sensor if the left plug cannot be reached.
4. Remove the coolant recovery reservoir.
5. Close the radiator drain cock.

Notice: When fasteners are removed, always reinstall them at the same location from which they were removed. If a fastener needs to be replaced, use the correct part number fastener for that application. If the correct part number fastener is not available, a fastener of equal size and strength (or stronger) may be used. Fasteners that are not reused and those requiring thread locking compound will be called out. The correct torque value must be used when installing fasteners that require it. If the above conditions are not followed, parts or system damage could result.

6. Install the cylinder block block drain plugs.

Tighten
- Drain plugs to 21 Nm (15 lb. ft.).

7. Add enough water to fill the cooling system.
8. Run the engine until the thermostat opens.
9. Stop the engine. Repeat steps 1 through 8, until the drained fluid is nearly colorless.

Notice: Use ethylene glycol coolant, meeting GM specifications 1825-M, to provide the required freezing and corrosion protection - at least 50 precent solution -37°C (-34°F). Alcohol or methanol base coolant or plain water are not recommended at any time. This is due to their poor corrosion protection and protection against freezing. A solution stronger than 70 percent should never be used. The solution's freeze point rises after this point. Pure antifreeze will freeze at -20°C (-4°F).

10. Install the coolant recovery reservoir.
11. Add enough water and ethylene glycol antifreeze (meeting GM specifications 1825-M) to provide a solution that is at least 50 percent antifreeze, but no more than 70 percent antifreeze. For cooling system capacities, refer to Capacity Specifications.
- Fill the radiator to below the filler neck.
- Fill the coolant recovery reservoir to the "COLD FILL" mark.
- Install the coolant recovery reservoir cap.
12. Run the engine with the radiator cap removed until normal operating temperature is reached (radiator inlet hose becomes hot).
13. With the engine idling, add coolant to the radiator until the level reaches the bottom of the filler neck.

Caution: Under some conditions, ethylene glycol is engine coolant is flammable. To avoid being burned when adding coolant, do not spill it on the exhaust system or on hot engine parts.

14. Install the radiator cap.
- The arrows on the cap must line up with the coolant recovery reservoir hose.

Important:
- It is the owner's responsibility to:
- Keep the freeze protection at a level appropriate to the temperatures which may occur in the area the vehicle may be operating.
- Maintain cooling system freeze protection at -37°C (-34°F) to ensure protection against corrosion.