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.

Notice: When adding coolant, use DEX-COOL® coolant. If silicated coolant is added to the system, premature engine, heater core or radiator corrosion may result. In addition, the engine coolant will require change sooner-at 50 000 km (30,000 mi) or 24 months.

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. Refer to Radiator Assembly .

3.1. | Clean the cap.

3.2. | Test the cap. Refer to Radiator Diagnosis .

3.3. | If necessary, replace the cap.

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

4. Disconnect the hose from the coolant recovery reservoir. Remove the reservoir. Refer to Coolant Recovery Reservoir Replacement .

4.1. | Clean the outside of the coolant recovery reservoir.

4.2. | Pour out any fluid.

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

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

5. Install the reservoir. Connect the reservoir hose. Refer to Coolant Recovery Reservoir Replacement .

### Filling Procedure

1. Close the radiator drain cock.

Notice: Pure coolant can be added to raise the boiling point of the coolant, but too much will affect the freezing point. Do not use a solution stronger than 70 percent, as the freeze level rises rapidly after this point. Pure coolant will freeze at -22°C (-8°F).

2. Refill the cooling system. In order to ensure sufficient engine cooling, freezing and corrosion protection, maintain the coolant protection level at -37°C (-34°F) or lower.
3. Set the heater/A/C control in any A/C mode except MAX. Set the temperature to the highest setting.
4. Allow the engine to continue idling until the radiator outlet hose becomes hot.
5. 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.
6. After the air has been released, fill the radiator with coolant. Install the radiator pressure cap. Refer to Radiator Assembly . The arrows on the pressure cap must line up with the reservoir overflow hose.
7. 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.

### Engine Coolant Recycling

#### Tools Required

GM approved Recycling System such as Pro Clean (Available in the GM Dealer Equipment Program)

Whenever the cooling system needs maintenance or repairs, remove and replace the coolant with qualified new or recycled coolant.

If you only drain the radiator, up to 50 percent of the used, contaminated coolant can remain in the cooling system.

Use any of the following methods in order to remove the coolant:

• | Use a waterless coolant evacuation system, available in the GM Dealer Equipment program, or equivalent, that removes the used coolant and replaces the coolant with new or recycled coolant.

• | Use a GM approved coolant recycling system, available in the GM Dealer Equipment program, or equivalent, that recycles the coolant on the vehicle. This eliminates the need for coolant evacuation.

| Important: Do not recycle coolant on vehicles manufactured with GM Goodwrench Dex-Cool.

• | Recover the used coolant. Store the coolant in a used coolant holding tank. Submit the used coolant for recycling on a regular basis.