Draining Procedure

Important:  Do NOT add any engine coolant supplement sealant pellets to the cooling system. Drain and refill the engine cooling system every 5 years or 240 000 km, (150,000 mi), whichever occurs first.

1. Park the vehicle on a level surface.
2. Remove and clean the coolant recovery reservoir.
   CAUTION: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot.
3. Remove the radiator cap when the engine is cool:
   1. 3.1. Slowly rotate the cap counterclockwise to the detention tab. Do not press down while rotating pressure cap.
   2. 3.2. Wait until any residual pressure, indicated by a hissing sound, is relieved.
   3. 3.3. After all hissing stops, press down on the radiator cap and rotate the cap counterclockwise in order to remove the cap.
   Fig 1: Removing Radiator Cap

   Courtesy of GENERAL MOTORS CORP.

   Important:  Recover and store used coolant in a used coolant holding tank and submit the used coolant for recycling on a regular basis. Do NOT pour used coolant down the drain. Ethylene glycol antifreeze is very toxic. Disposing of ethylene glycol into the sewer system or ground water is both illegal and ecologically unsound.

4. Place a drain pan under the radiator drain cock in order to collect all of the used coolant.
5. Open the radiator drain cock.

   If only partial cooling system draining is required, drain enough coolant to perform the procedure.

   Fig 2: Removing Radiator Drain Cock

   Courtesy of GENERAL MOTORS CORP.
6. Open the air bleed valve on the thermostat housing 2 full turns.
   Fig 3: Turning Air Bleed Valve On Thermostat Housing

   Courtesy of GENERAL MOTORS CORP.
7. Open the air bleed valve above coolant pump 2 full turns.
8. Place a drain pan under the engine block drains in order to collect the used coolant.
   Fig 4: Turning Air Bleed Valve Above Coolant Pump

   Courtesy of GENERAL MOTORS CORP.

   Important:  Allow the coolant to drain completely.

9. Remove both of the engine block drains.
   • The front left engine block drain is located between the starter motor and the engine oil filter.
   • The rear right engine block drain is located near the crankshaft position sensor.
   Fig 5: Removing Both Of Engine Block Drains

   Courtesy of GENERAL MOTORS CORP.