Repair Instructions: Flushing
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT:
Do not use a chemical flush. Store used coolant in the proper manner, such as in a used engine coolant holding tank. Do not pour used 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. Various methods and equipment can be used to flush the cooling system. If special equipment is used, such as a back flusher, follow the manufacturer's instruction. Always remove the thermostat before flushing the cooling system.
When the cooling system becomes contaminated, the cooling system should be flushed thoroughly to remove the contaminants before the engine is seriously damaged.
- Drain the cooling system. Refer to Draining and Filling Cooling System (LL8) or Draining and Filling Cooling System (LM4) .
- Remove the coolant recovery reservoir. Refer to Coolant Recovery Reservoir Replacement .
- Clean and flush the coolant recovery reservoir with clean, drinkable water.
- Install the coolant recovery reservoir. Refer to Coolant Recovery Reservoir Replacement .
- Remove the thermostat. Refer to Thermostat Replacement (4.2L Engine) or Thermostat Replacement (5.3L Engine) .
- Follow the drain and fill procedure using only clean, drinkable water. Refer to Draining and Filling Cooling System (LL8) or Draining and Filling Cooling System (LM4) .
- Run the engine for 20 minutes.
- Stop the engine.
- Drain the cooling system. Refer to Draining and Filling Cooling System (LL8) or Draining and Filling Cooling System (LM4) .
- Repeat the procedure if necessary, until the fluid is nearly colorless.
- Install the thermostat. Refer to Thermostat Replacement (4.2L Engine) or Thermostat Replacement (5.3L Engine) .
- Fill the cooling system. Refer to Draining and Filling Cooling System (LL8) or Draining and Filling Cooling System (LM4) .