Repair Instructions: Flushing

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. DEX-COOL antifreeze is a 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. However, always remove the thermostat before back flushing the system.

1. Block the drive wheels.
2. Place the transmission in park (P) or neutral (N).
3. Engage the park brake.
4. Remove the thermostat. Refer to Thermostat Replacement (3.8L Engine)  or Thermostat Replacement (5.7L Engine) .
5. Fill the cooling system with water only. Refer to Draining and Filling Cooling System .
6. Run the vehicle until normal operating temperature is reached.
7. Drain the cooling system. Refer to Draining and Filling Cooling System .
8. Repeat until the drained water is nearly colorless.
9. Remove, clean and install the coolant recovery reservoir. Refer to Coolant Recovery Reservoir Replacement .
10. Install the thermostat. Refer to Thermostat Replacement (3.8L Engine)  or Thermostat Replacement (5.7L Engine) .