For 1990-2009 cars

### Draining Procedure

Caution: As long as there is pressure in the cooling system, the temperature can be considerably higher than the boiling temperature of the solution in the radiator without causing the solution to boil. Removal of the pressure cap while the engine is hot and pressure is high will cause the solution to boil instantaneously -- possibly with explosive force -- spewing the solution over the engine, fenders and the person removing the cap.

1. Completely drain the cooling system by opening the radiator drain cock at the bottom of the radiator.
2. If the coolant is dirty, or if there are deposits in the radiator, flush the cooling system before refilling. Refer to Flushing .
3. Remove the radiator pressure cap.

3.1. | Clean the cap.

3.2. | Test the cap.

3.3. | If necessary, replace the cap.

3.4. | Clean the radiator filler neck. Inspect the filler neck.

4. Disconnect all hoses from the coolant reservoir. Remove the reservoir. Refer to Coolant Recovery Reservoir Replacement .

4.1. | Pour out any fluid.

4.2. | Thoroughly clean the inside of the reservoir using soap and water.

4.3. | Thoroughly flush the reservoir with clean water. Drain the reservoir.

5. Install the reservoir. Connect the reservoir hose. Refer to repair.

### Filling Procedure

1. Close the radiator drain cock.
2. Install the block drain plugs, if removed.
3. Refill the cooling system:

• | Use GM Goodwrench® DEX-COOL® or Havoline® DEX-COOL®. In order to ensure sufficient engine cooling, freezing and corrosion protection, maintain the coolant protection level at -37°C (-34°F) or lower.

• | Use a solution that is no more than 70 percent antifreeze.

4. Set the heater and A/C control in any A/C mode except MAX. Set the temperature to the highest setting.
5. Allow the engine to continue idling until the lower radiator to coolant pump hose is hot.
6. Cycle the engine speed up to about 3,000 RPM and back to idle 5 times. Slowly open the bleed valve on the rear of the coolant outlet for about 15 seconds in order to release any trapped air in the cooling system.
7. After the air has been released, fill the radiator with coolant. Install the radiator pressure cap. The arrows on the pressure cap must line up with the coolant recovery tube.
8. Allow the engine to cool to the outside temperature. Then, check the coolant level in the coolant recovery reservoir. The coolant level should be at the FULL COLD mark. If not, add the coolant until the level reaches the FULL COLD mark.