Draining and Refilling

Coolant Surge Tank:

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

1. Park the vehicle on a level surface.
2. Remove the surge tank cap, when the engine is cool, by:
- Slowly rotating cap counterclockwise about a 1/4 turn and then stop.
- Wait until any residual pressure (indicated by a hissing sound) is relieved.
- After all hissing stops, continue to rotate counterclockwise until the cap is removed.
3. Open the radiator drain valve located at the bottom left hand of the radiator tank.
- For procedures requiring the cooling system to be partially drained, opening the radiator drain valve should provide sufficient draining; and no further actions should be necessary.

WARNING: Never pour used coolant down the drain. Ethylene glycol antifreeze is a very toxic chemical; disposing of it into the sewer system or ground water is both illegal and ecologically unsound!

4. Remove engine block drain plug.
5. Allow the coolant to drain completely. Important
- Dispose of used coolant in a proper fashion, i.e., in a used coolant holding tank.
6. Inspect The drained coolant:
- If the coolant is discolored, flush the cooling system.
- If the coolant appearance is normal, continue with the filling procedure.


FILLING
1. Close the radiator drain valve.
2. Install all engine block drain plugs if previously removed. Use pipe sealer when installing drain plugs.

CAUTION: Under some conditions, the ethylene glycol in engine coolant is combustible. To help avoid being burned, DO NOT spill antifreeze or coolant on the exhaust system or hot engine parts.

3. Refill the cooling system with coolant meeting GM Specification 1825-M. To ensure sufficient engine cooling, freezing and corrosion protection, maintain the protection level at -37° C (-34° F) or lower. Use a solution that is no more than 70 percent antifreeze.

NOTE: When refilling the engine cooling system, add engine coolant supplement sealant, GM Part #3634621 or equivalent, and coolant antifreeze meeting GM specification 1825-M. Add (2) coolant pellets.

4. Fill surge tank with the proper mix of coolant to just above the "Small Cylinder" at the base. of the tank opening or until the level
5. With the pressure cap off, start the engine and let it run until the upper radiator hose starts to get hot.

CAUTION: Keep hands clear of fan.

6. If coolant is lower then "Small Cylinder", add proper mix of coolant to the surge tank until the level reaches the "Split line."
7. Install the surge tank pressure cap onto the surge tank with hand tight pressure.
- After servicing the cooling system, an occasional intermittent low coolant light (if equipped) may be encountered during some extreme driving maneuvers. This complaint should be eliminated by removing the surge tank cap and adding coolant to a level just at or above the "Split Line" when the system is cold.