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. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
3. Place a drain pan under the drain cock.
4. Open the radiator drain cock.
5. Drain the cooling system.
6. If a complete engine block drain is required, LG8 engine, remove the engine block drain plugs.
7. If a complete engine block drain is required, L36 or L67 engine, remove the knock sensors. Refer to Knock Sensor 1 Replacement and Knock Sensor 2 Replacement in Engine Controls - 3.8L (L36 and L67).
8. Inspect the coolant.
9. Follow the appropriate procedure based on the condition of the coolant.

•	Normal in appearance -- follow the filling procedure.

•	Discolored -- follow the flush procedure. Refer to Flushing .

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

1. Close the radiator drain cock.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

2. If the engine block drain plugs were removed from the LG8 engine, perform the following:

2.1.	Apply pipe sealer to the drain plugs.

2.2.	Install the drain plugs.

Tighten
Tighten the drain plugs to 22 N·m (16 lb ft).

3. If the engine block was drained, L36 or L67 engine, install the knock sensors. Refer to Knock Sensor 1 Replacement and Knock Sensor 2 Replacement in Engine Controls - 3.8L (L36 and L67).
4. Lower the vehicle.
5. Open the cooling system bleeder screws.

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

6. Slowly fill the cooling system with a 50/50 coolant mixture. Refer to Approximate Fluid Capacities in Maintenance and Lubrication.
7. Close the cooling system bleeder screws.
8. Install the coolant pressure cap.
9. Start the engine.
10. Run the engine at 2,000-2,500 RPM until the engine reaches normal operating temperature.
11. Allow the engine to idle for 3 minutes.
12. Shut the engine OFF.
13. Allow the engine to cool.
14. Top off the coolant as necessary.
15. Inspect the concentration of the engine coolant, using the J 26568 .
16. Rinse away any excess coolant from the engine and the engine compartment.