Draining and Filling Cooling Systems

Draining Procedure

^ Tools Required
- J 26568 Coolant and Battery Tester

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. Remove the coolant pressure cap.
2. Place a drain pan under the drain cock.
3. Open the radiator drain cock.
4. Drain the cooling system.
5. If a complete engine block drain is required L26 or L32 engine, remove the knock sensors.
6. Inspect the coolant.
7. Follow the appropriate procedure based on the condition of the coolant.
^ Normal in appearance-follow the filling procedure.
^ Discolored-follow the flush procedure.


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.

Notice: Refer to Fastener Notice in Service Precautions

1. Close the radiator drain cock.
2. If the engine block was drained L26 or L32 engine install the knock sensors.
3. Open the cooling system bleeder screws.

Important: Use a 50/50 mixture of DEX-COOL antifreeze and clean, drinkable water.

4. Slowly fill the cooling system with a 50/50 coolant mixture.
5. Close the cooling system bleeder screws.
6. Install the coolant pressure cap.
7. Start the engine.
8. Run the engine at 2,000 - 2,500 RPM until the 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 concentration of the engine coolant using the J 26568.
14. Rinse away any excess coolant from the engine and the engine compartment.