Draining and Filling Cooling Systems
Draining and Filling Cooling System^ Tools Required
- J 38185 Hose Clamp Pliers
Draining Procedure
Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot. 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 pressure cap while the engine is hot and pressure is high will cause the solution to boil instantaneously - possibly with explosive force - spewing the solution over the engine, fenders and the person removing the cap.
1. Remove the radiator filler cap.
2. Place a drain pan under the lower radiator hose.
3. Using a J 38185 reposition the radiator inlet hose clamp from the radiator.
4. Remove the radiator inlet hose from the radiator.
5. Allow the cooling system to drain until the flow stops. If only the radiator is drained, up to 40 percent of the old coolant will remain in the system.
6. Place a drain pan under the engine.
7. Remove the drain plug from the side of the engine block, if equipped with a 2.2L.
8. Remove the drain plugs from each side of the engine block, if equipped with a 4.3L.
^ There may be more drainage from the radiator at this time.
^ Allow the engine block to drain until the flow stops.
Notice: Refer to Fastener Notice in Service Precautions.
Important: Dispose of the used engine coolant properly. Store the used coolant in a used coolant Holding Tank awaiting proper disposal. Do not pour used coolant down the drain. Dex-Cool antifreeze is a very toxic chemical. Disposal into the sewer system or into the ground water is both environmentally irresponsible and illegal.
^ If the drained coolant is discolored, flush the cooling system.
^ If the drained coolant appears normal, continue with the filling procedure.
9. Apply sealer, GM P/N 12346004 (Canadian P/N 10953480) to the threads and then tighten the engine block drain plugs.
^ Tighten the engine block drain plugs 2.2L to 15 Nm (11 ft. lbs.).
^ Tighten the engine block drain plugs 4.3L to 18 Nm (13 ft. lbs.).
Filling Procedure
Notice: Do not add cold water to the cooling system with the engine at or above operating temperature. Adding cold water causes rapid cooling, resulting in possible engine damage. Do not use a solution stronger than 70 percent antifreeze. Pure antifreeze can freeze at -22°C (-8°F).
1. Install the radiator inlet hose to the radiator.
2. Using J 38185 reposition the radiator inlet hose clamp to the radiator.
3. Place a large mouth funnel in the radiator fill opening.
Important: Under some conditions, Dex-Cool is combustible. Do not spill the coolant onto the exhaust system or other hot engine parts.
4. Slowly add a 50/50 mixture of Dex-Cool and clean drinkable water.
5. Fill to 1/2 inch below the radiator fill opening.
6. Start the engine.
7. As the cooling system warms up and the thermostat opens, the coolant level will drop.
8. Add coolant until the level is up to the radiator fill opening.
9. Replace the radiator filler cap.
10. Inspect the level in the coolant recovery reservoir, add coolant if needed.