Caution: The radiator cap should be removed from a cool engine only. If the radiator cap is removed from a hot cooling system, serious personal injury may result.

Caution: As long as there is pressure in the cooling system, the temperature can be considerably higher than the boiling temperature of the solution in the radiator, without causing the solution to boil. Removal of the radiator cap while the engine is hot and the pressure is high will cause the solution to boil instantaneously and possibly with explosive force, spewing the solution over the engine, fenders, and person removing the cap. Under some conditions, the engine coolant is combustible.

1. Place a drain pan under the radiator drain cock. Ensure that the capacity of the drain pan is 32 quarts (30 liters).
2. Ensure that the system is cool. Remove the radiator cap.
3. Open the drain cock at the bottom of the radiator.
4. Allow the cooling system to drain until the coolant flow stops.
5. Remove the drain plug from the cylinder block.
6. Allow the engine block to drain until the coolant flow stops. There may be additional drainage from the radiator at this time.
7. Replace the engine block drain plug.
8. Close the radiator drain cock.

Notice: Two sealant pellets GMSPO P/N 3634621 must be added to the radiator whenever the coolant system is drained and refilled with fresh coolant. Failure to use the correct sealant pellets may result in premature water pump leakage. Do not add the pellets to the coolant recovery bottle since this may prevent the coolant system from operating properly.

Notice: When adding coolant, it is important that you use GM Goodwrench DEX-COOL™ coolant. If coolant other than DEX-COOL™ is added to the system, the engine coolant will require change sooner: at 50 000 km (30,000 miles) or 24 months.

Use the following procedure in order to fill the cooling system:

1. Ensure the engine block and radiator drain plugs are installed and closed.



2. Add 2 sealant pellets to the radiator.
3. Add approximately 11L (11.5 quarts) of coolant (Dex-Cool™) to the radiator. Refer to Engine Cooling System Specifications for the cooling system capacity. Do not pre-mix the coolant and water.
4. Fill the remainder of the radiator with clean drinkable water in order to equal a 50/50 mixture. The filling may be slowed due to the thermostat being closed.
5. Fill the surge tank to the cold engine level.
6. Start the engine and allow to warm. When the thermostat opens, the coolant level may drop. Add additional water as needed.
7. Recheck the coolant level. Add water as needed. The system should hold approximately 21.3 liters (22.5 quarts).