GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 26568 Coolant and Battery Tester
    • 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.

    Important: Draining the cooling system with the pressure cap installed will syphon the coolant from the overflow tank.

  1. Park the vehicle on a level surface.
  2. Allow the engine to cool.
  3. Remove the radiator cap.
  4. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  5. Place a drain pan under the lower radiator hose connection at the bottom of the radiator.
  6. Using J 38185 slide the hose clamp back on the lower radiator hose.
  7. Slowly remove the lower radiator hose and drain the coolant into the drain pan.
  8. Inspect the engine coolant for the following:
  9. • Discolored appearance - follow the flush procedure. Refer to Flushing .
    • Normal in appearance - follow the filling procedure.
    • If a complete block drain is required, remove the coolant heater located on the LH side of the block. Refer to Coolant Heater Replacement .

Filling Procedure

Notice: The procedure below must be followed. Improper coolant level could result in a low or high coolant level condition, causing engine damage.

  1. If a complete block drain was required, install the coolant heater. Refer to Coolant Heater Replacement .
  2. Install the lower radiator hose.
  3. Using the J 38185 slide the lower radiator hose clamp into the original position.
  4. Lower the vehicle.
  5. Important: Slowly add a mixture of 50/50 DEX-COOL antifreeze and deionized water to the cooling system through the top of the radiator until full. Refer to Approximate Fluid Capacities in Maintenance and Lubrication.

  6. Install the radiator cap.
  7. Remove coolant recovery reservoir cap.
  8. Fill the coolant recovery reservoir with the remaining coolant.
  9. Install coolant recovery reservoir cap.
  10. Start the engine.
  11. Run the engine at 2,000-2,500 RPM until the engine reaches normal operating temperature.
  12. Allow the engine to idle for 3 minutes.
  13. Shut the engine off.
  14. Allow the engine to cool.
  15. Top off the coolant recovery reservoir as necessary.
  16. Inspect the cooling system for leaks.
  17. Rinse away any excess coolant from the engine and the engine compartment.
  18. Inspect the concentration of the engine coolant using J 26568 .