GM Service Manual Online
For 1990-2009 cars only

Draining Procedure

    Caution: Under pressure, the temperature of the solution in the radiator can be considerably higher, without boiling. Removing the radiator cap while the engine is hot (pressure is high), will cause the solution to boil instantaneously, with explosive force. The solution will spew out over the engine, fenders, and the person removing the cap. Serious bodily injury may result. Flammable antifreeze, such as alcohol, is not recommended for use at any time. Flammable antifreeze could cause a serious fire.

  1. Place a drain pan under the radiator drain cock.
  2. Place the end of the tube in the drain pan.
  3. After the engine cools down, remove the radiator cap.
  4. Turn the drain cock counterclockwise in order to allow the coolant to drain.
  5. Allow the coolant to drain from the system until the flow stops.
  6. Place a drain pan under the engine block drain hole plug.
  7. Remove the drain hole plug from the engine block.
  8. Allow the coolant to drain from the block until the flow stops. There may be more drainage from the radiator at this time.
  9. Install the block drain hole plug.
  10. Close the radiator drain cock.

Filling Procedure

    Notice: When adding coolant, use DEX-COOL® coolant. If silicated coolant is added to the system, premature engine, heater core or radiator corrosion may result. In addition, the engine coolant will require change sooner-at 50 000 km (30,000 mi) or 24 months.

  1. Check to make sure that the radiator drain cock is closed.
  2. Check to make sure that the block drain hole plug is tight.
  3. Add the DEX-COOL® to the radiator, then add clean drinkable water to the cooling system. If you use the old coolant, make sure the solution is clean and clear, and that the solution is a 50/50 mixture of glycol and water.
  4. Place a large top funnel in the radiator filler neck or surge tank.
  5. Slowly pour in the coolant. Because the thermostat is closed, filling the cooling system may be slow.
  6. After filling the cooling system to 13 mm (0.5 in) below the radiator filler neck (Gas Engines) or to the full mark on the surge tank (Diesel Engines), start the engine and let the cooling system warm up. When the thermostat opens, the coolant level may drop. If the level drops, add coolant as necessary.
  7. Install the radiator or surge tank cap.
  8. Check the coolant level in the coolant recovery reservoir (Gas Engines) or the surge tank (Diesel Engines). Add coolant as necessary.