Draining Procedure
- Park the vehicle on a level surface.
- Remove the coolant recovery reservoir. Clean the reservoir. Refer to Coolant Recovery Reservoir Replacement .
- When the engine is cool, remove the radiator filler cap . Refer to Radiator Assembly .
- Place a drain pan under the radiator to recover the coolant.
- Open the radiator drain cock at the bottom of the radiator. For procedures where you partially drain the cooling system, opening the drain cock should provide sufficient draining. No further action should be required.
- Remove the thermostat housing cap and thermostat or open the air bleed vents. These vents are on the coolant outlet and the heater coolant inlet pipe near the brake master cylinder. Open the vents two or three turns.
- Remove the coolant drain hole plug by the engine crank sensor.
- Allow the coolant to completely drain.
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.
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.
Important: Remove the coolant and store it in a used coolant holding tank and submit the used coolant for recycling on a regular basis. This procedure significantly increases the amount of used coolant and diluted hazardous waste.
Notice: Dispose of used engine coolant in the proper manner, such as in a used engine coolant holding tank. DO NOT POUR USED ENGINE COOLANT DOWN A DRAIN! Ethylene glycol antifreeze is a very toxic chemical. Do not dispose of coolant into the sewer system or ground water. This is illegal and ecologically unsound.
Filling the Cooling System
- Close the radiator drain valve.
- Reinstall all of the engine block drains.
- Reconnect the inlet hose to the engine oil cooler.
- Install the coolant recovery reservoir. Refer to Coolant Recovery Reservoir Replacement .
- Slowly fill the cooling system through the radiator neck using the following procedure:
- Install the radiator cap. Line up the arrows (1) with the overflow tube (2).
- Close all of the air bleeds. Do not overtighten the air bleed valve. The air bleed valve is made of brass.
- Fill the recovery reservoir with a 50 percent ethylene glycol and a 50 percent clean water coolant mixture. Install the proper amount of the coolant into the recovery reservoir. For all engines, add 1.7 liters (1.8 quarts) of a 50/50 mixture of ethylene glycol and clean water to the coolant recovery reservoir.
- Inspect the freeze protection of the engine coolant. Refer to Coolant Concentration Testing .
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.
Notice: The Low Coolant warning/indicator lamp may come on after this procedure. After operating the vehicle so that the engine heats up and cools down three times, the Low Coolant warning/indicator lamp does NOT go out, or fails to come on at the ignition check, and the coolant is at the level indicated in step 3, refer to SECTION 8A-90 or 8A-81. If at any time the TEMP warning/indicator lamp comes on, immediate action is required.
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.
Important:
• When you refill the cooling system, add 2 engine coolant supplement
sealant pellets, GM P/N 3634621, or equivalent. • The front heater system only requires 5.6L (5.8 Quarts of ethylene
glycol). • The rear heater system requires 6.3L (6.7 quarts of ethylene glycol). • If the cooling system is being refilled only, no flushing, use
a 50 percent ethylene glycol and 50 percent clean water mixture to fill the
system. Fill the system until the level of the 50/50 mixture reaches the base
of the radiator filler neck. Wait 2 minutes, then recheck the level of the
coolant. If necessary, add a 50/50 ethylene glycol/water mixture to restore
the coolant level to the base of the radiator neck.
| 6.1. | If the cooling system has been flushed, first add 100 percent ethylene glycol. Refer to the coolant static fill capacity chart for the appropriate engine application. |
| 6.2. | Slowly add clean water to the system until the level of the coolant reaches the base of the radiator neck. |
| 6.3. | After 2 minutes, recheck the level of the coolant mixture. |
| 6.4. | If necessary, add clean water to restore the coolant level to the base of the radiator neck. |
Notice: The Low Coolant warning/indicator lamp may come on after this procedure. After operating the vehicle so that the engine heats up and cools down three times, the Low Coolant warning/indicator lamp does NOT go out, or fails to come on at the ignition check, and the coolant is at the level indicated in step 3, refer to SECTION 8A-90 or 8A-81. If at any time the TEMP warning/indicator lamp comes on, immediate action is required.
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).
