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.

Every 12 months or 24 135 km (15,000 miles), whichever occurs first, service the items listed under Cooling System Maintenance Recommendations .

Every 5 years or 166 000 km (100,000 miles), whichever occurs first, drain the cooling system using the following procedures:

1. Park the vehicle on a level surface.

Caution: Under pressure, the temperature of the solution in the radiator can be considerably higher, without boiling. Removing the radiator cap while the engine is hot (pressure is high), will cause the solution to boil instantaneously, with explosive force. The solution will spew out over the engine, fenders, and the person removing the cap. Serious bodily injury may result. Flammable antifreeze, such as alcohol, is not recommended for use at any time. Flammable antifreeze could cause a serious fire.

2. When the engine is cool, remove the filler cap from the radiator surge tank. Refer to Radiator Filler Cap Assembly .



3. Open the radiator drain cock. This is at the bottom of the right-hand radiator end tank.



4. Remove the engine knock sensors and the engine block coolant drain hole plug from the lower right-hand and left-hand side of the engine block.
5. Allow the system to completely drain.
6. Inspect the drained coolant.

Notice: Do not use a chemical flush. This could cause damage to the cooling system.

•	If the coolant is discolored, flush the cooling system. Refer to Flushing .

•	If the coolant appearance is normal, continue with the refilling procedure.

1. Close the radiator drain cock.



2. Install the engine knock sensors and the drain hole plugs.
3. Slowly fill the cooling system through the filler cap opening in the radiator surge tank using clean water. The level of the water should be at the base of the surge tank neck.
4. Close both of the bleed valves when a solid stream of water comes out of each valve.
5. Install the filler cap on the radiator surge tank.

Important: 

1. Block the drive wheels.
2. Place the transmission in PARK or NEUTRAL.
3. Set the parking brake.
6. Idle the engine until the thermostat opens, coolant temperature is approximately 93°C (200°F). Then, turn OFF the engine.

Caution: Monitor the coolant temperature gauge while the engine is running during the coolant drain, flush, and refill procedure. If the temperature reaches the 260° mark or the hot light comes ON immediately, turn OFF the engine. Allow the engine to cool completely. The coolant temperature should be 27°C (80°F). After the engine has cooled down sufficiently, restart the engine and continue with the drain, flush, and refill procedure. Continue to monitor the coolant temperature gauge any time the engine is running during the coolant drain, flush, and refill procedure.

7. Drain and refill the system a sufficient number of times until the drained fluid is nearly colorless.
8. Remove the coolant recovery reservoir. Empty the reservoir. Refer to Coolant Recovery Reservoir Replacement . Install the reservoir.
9. Slowly fill the cooling system through the opening in the radiator surge tank using the following procedure:

•

If the cooling system has been flushed, first add 7.7 L (8.2 qts) of 100 percent GM Goodwrench DEX-COOL™. Then slowly add clean water to the system until a solid stream of coolant mixture comes out of each bleed valve. Then, close each bleed valve. Continue adding water to the system until the level of the coolant mixture reaches the base of the surge tank neck.

•

If the cooling system is being refilled only, no flushing, use a 50/50 mixture of GM Goodwrench DEX-COOL™ and clean water to fill the system. Fill the system until a solid stream of the 50/50 coolant mixture comes out of each bleed valve. Then, close each bleed valve. Add the 50/50 mixture until the level reaches the base of the neck of the radiator surge tank. Wait two minutes, then recheck the level of the coolant mixture. If necessary, add a DEX-COOL™/ water coolant mixture in order to restore the coolant level to the base of the radiator surge tank neck.

10. Start the engine. Allow the engine to idle for 4 minutes. During this time, continue to fill the cooling system with a DEX-COOL™/ water mixture through the opening in the radiator surge tank until the coolant level is maintained at the base of the surge tank neck. Monitor the coolant temperature gauge at all times when the engine is idling.
11. After 4 minutes of engine operation, or once the level of the coolant/water mixture is maintained at the base of the neck of the radiator surge tank, whichever occurs first, turn OFF the engine. Add six cooling system sealer pellets, GM P/N 3634621, through the opening in the radiator surge tank.



12. Install the filler cap on the radiator surge tank. The arrows on the cap must line up with the overflow tube.
13. Fill the coolant recovery reservoir with 1.8 L (1.9 qts) of a DEX-COOL™/ water mixture.
14. Rinse any excess coolant from the engine.

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: