GM Service Manual Online
For 1990-2009 cars only

Cooling System Draining and Filling LA3, LY9

Tools Required

J 38185 Hose Clamp Pliers

Draining Procedure

Caution: With a pressurized cooling system, the coolant temperature in the radiator can be considerably higher than the boiling point of the solution at atmospheric pressure. Removal of the surge tank cap, while the cooling system is hot and under high pressure, causes the solution to boil instantaneously with explosive force. This will cause the solution to spew out over the engine, the fenders, and the person removing the cap. Serious bodily injury may result.

  1. Park the vehicle on a level surface.
  2. Remove the surge tank cap.
  3. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  4. Remove the air deflector. Refer to Front Air Deflector Replacement in Body Front End.
  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 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 block drain located on the LH side of the block. Fill the system using the Special Coolant Fill Procedure.

Tools Required

    • J 26568 Coolant and Battery Fluid Tester
    • J 38185 Hose Clamp Plier

Fill Procedure

Important: Due to the system configuration, standard filling procedure may not ensure a complete system fill. The standard coolant fill procedure applies to conditions where coolant was drained only through the radiator hose. The special coolant fill procedure must be used if any of the following events have occurred.

    • Engine block drain removed or replaced.
    • Water pump seal is broken or pump was replaced.
    • Thermostat removal.
    • Auxiliary coolant pump removal.
    • Complete engine removed or replace.

Standard Coolant 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. Install the lower radiator hose.
  2. Using the J 38185 slide the clamp into the original position.
  3. Lower the vehicle.
  4. Slowly add a mixture of 50/50 DEX-COOL antifreeze and deionized water to the cooling system through the top of the surge tank opening. Refer to Approximate Fluid Capacities in General Information.
  5. Fill the cooling system until the coolant reaches the FULL COLD mark on the surge tank.
  6. Install surge tank cap.
  7. Start the engine.
  8. Run the engine at 2,000-2,500 RPM until engine reaches normal operating temperature.
  9. Allow the engine to idle for 3 minutes.
  10. Shut the engine OFF.
  11. Allow the engine to cool.
  12. Top off the coolant as necessary.
  13. Inspect the cooling system for leaks.
  14. Rinse away any excess coolant from the engine and the engine compartment.
  15. Inspect the concentration of the engine coolant using J 26568 .
  16. Install the air deflector. Refer to Front Air Deflector Replacement in Body Front End.

Special Coolant Fill 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. Install the lower radiator hose.
  2. Using the J 38185 slide the clamp into the original position.
  3. Lower the vehicle.
  4. Using the J 38185 remove the upper radiator hose from the radiator connection.
  5. Slowly add a mixture of 50/50 DEX-COOL antifreeze and deionized water to the cooling system through the top of the radiator opening. Refer to Approximate Fluid Capacities in General Information.
  6. Fill the upper radiator hose and engine with the 50/50 coolant mixture.
  7. Connect the upper radiator hose to the engine.
  8. Using the J 38185 slide the radiator hose clamp into the original position.
  9. Fill the surge tank to the FULL COLD.
  10. Install the surge tank cap.
  11. Idle the engine for 2 minutes and occasionally raise the throttle to 3,000-3,500 RPM.
  12. Shut off the engine and allow it to cool.
  13. Repeat the steps 1-9.
  14. Idle the engine for 2 minutes and occasionally raise the throttle to 3,000-3,500 RPM.
  15. Inspect the surge tank for consistent flow.
  16. If there is no flow through surge tank repeat steps 1-9.
  17. Install the air deflector. Refer to Front Air Deflector Replacement in Body Front End.
  18. Allow engine to cool.
  19. Remove the surge tank cap and fill to the FULL COLD.