Draining, Flushing and Filling the Cooling System

Every two years or 30,000 miles whichever first occurs, the cooling system should be drained and filled using the following recommended procedures:

NOTE Used ethylene glycol MUST be disposed of in accordance with Federal, State, and local laws.

1. Park vehicle on a level surface.

WARNING To avoid being burned, DO NOT remove the radiator cap while the engine is at normal operating temperature. The cooling system will release scalding fluid and steam under pressure if the cap is removed while the engine and radiator are still hot.

2. Remove the radiator cap when the engine is cool by:
a. Slowly rotating counterclockwise to detent. (DO NOT press down while rotating.)
b. Wait until any residual pressure (indicated by a hissing sound) is relieved.
c. After all hissing stops, press down on the cap while continuing to rotate counterclockwise.

Radiator Drain:

3. Open the radiator drain valve located at the bottom of the left-hand radiator end tank.

Thermostat:

4. Remove the thermostat housing cap and thermostat or open the air bleed vent(s):
- Open the air bleed vents on the thermostat housing and the throttle body return pipe above the coolant pump. The air bleed vents should be opened two to three turns.
5. Disconnect the negative cable from the battery.

Engine Coolant Drain Plug ( Front ):

Engine Coolant Drain Plug ( Rear ):

6. Remove engine block drain(s):
- The front engine block drain is located between the starter and engine oil filter.
- The rear engine block drain is located by the engine crank sensor.
7. Allow the system to drain completely then inspect the drained coolant:
a. If the coolant is discolored, flush the cooling system using Steps 8, 9, 10, and 11.
b. If the coolant appearance is normal continue with the refill procedure at Step 12.
8. Close the radiator drain valve. Reinstall all engine block drains and torque to 13 Nm ( 115 in. lb. ). Fill the cooling system through the radiator neck with clean water until the level of the water is at the base of the radiator neck. Install the radiator cap.
9. Close all air bleed vents opened in Step 4.
10. Reconnect the negative cable to the battery.

CAUTION Block drive wheels, place transaxle in "PARK" or "NEUTRAL" and set the parking brake.

11. Run the engine until the thermostat opens Coolant Temperature approximately 93°C or 200°F). Stop the engine, drain, and refill the system as described in Steps 1 through 10 (SEE CAUTION IN STEP 1). Repeat this process a sufficient number of times until the liquid drained is nearly colorless.
12. Close the radiator drain valve tightly. Reinstall all block drains and/or the inlet hose for the engine oil cooler removed in Step 6.
13. Remove the coolant recovery reservoir and empty. Flush the reservoir with clean water, drain and reinstall.

NOTE Use Ethylene Glycol coolant meeting GM specification 1825-M to provide the required freezing and corrosion protection, at least 5 percent solution, - 37°C (- 34°F).

14. Slowly fill the cooling system through the radiator neck using the following procedure:

NOTE If the cooling system has been flushed, first add 100 percent ethylene glycol 5.1L (171.1 oz.). Then slowly add clean water to the system until the level of the coolant mixture has reached the base of the radiator neck. Wait for two minutes and recheck the level of the coolant mixture, add clean water if necessary to restore the coolant mixture level to the base of the radiator neck.

NOTE If the cooling system is being refilled ONLY (no flush , a 50 percent ethylene glycol and 50 percent clean water mixture should be used to fill the system. Fill the system until the level of the 50/50 mixture has reached the base of the radiator neck. Wait two minutes and recheck the level of the coolant mixture, add a 50/50 ethylene glycol/water coolant mixture if necessary to restore the coolant mixture level to the base of the radiator neck.

15. Install radiator cap making certain the arrows line up with the overflow tube.
16. Close all air bleeds opened in Step 4. DO NOT over-torque the air bleed valve the air bleed valve is made out of brass.
17. Fill the coolant reservoir with a 50 percent ethylene glycol and a 50 percent clean water coolant mixture. Add 1.7L (1.8 qts.) of a 50/50 mixture of ethylene glycol and clean water to the coolant recovery reservoir.

NOTE The low coolant indicator lamp may come on after this procedure. After operating the vehicle so that the engine heats up and cools down three times, if the low coolant indicator lamp does NOT go out, or fails to come on at ignition check and coolant is at the level indicated in step 14, refer to engine wiring. If at any time the Temp warning indicator comes on, immediate action is required.

Inspect the freeze protection of the engine coolant after the engine heats up and cools down three times using a refractometer or a thermohydrometer to ensure proper freeze -37°C ( - 34°F) protection. 0btain the coolant mixture for the inspection from the base of the radiator neck, NOT from the coolant recovery reservoir. Refer to Testing Coolant Concentration.