GM Service Manual Online
For 1990-2009 cars only

    Caution: Refer to Radiator Cap Removal Caution in the Preface section.


    Object Number: 1224208  Size: SH

    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 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. Place a pan below the vehicle to catch the draining coolant.
  2. Remove the surge tank cap (1).
  3. Disconnect the lower radiator hose (2).
  4. Caution: Dispose of the used engine coolant properly. Store the used coolant in a used coolant Holding Tank awaiting proper disposal or recycling. Do not pour used coolant down the drain. Ethylene glycol antifreeze is a very toxic chemical. Disposal into the sewer system or into the ground water is both environmentally irresponsible and illegal

  5. Drain the coolant.

  6. Object Number: 1224210  Size: SH
  7. Connect the lower radiator hose.
  8. Remove all sludge and dirt from inside the surge tank. Install the surge tank (1). Refer to Radiator Surge Tank Replacement .

  9. Object Number: 1224212  Size: SH
  10. Add clean water to the surge tank (1).
  11. Run the engine until the thermostat opens. The thermostat is open when both radiator hoses are hot to the touch.
  12. Stop the engine and disconnect the lower radiator hose to drain the coolant.
  13. Repeat steps 5-9 until the drained water is clear and free of coolant and rust.
  14. 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.

  15. Fill the cooling system through the surge tank with a mixture of ethylene glycol antifreeze and water. The mixture must be at least 50 percent antifreeze, but not more than 60 percent antifreeze for cold weather operation.
  16. Fill the surge tank to the specified MAX fill mark on the outside of the tank.
  17. Install the surge tank cap.