Cooling System Flushing

Cooling System Flushing









1. WARNING: Always allow the engine to cool before opening the cooling system. Do not unscrew the coolant pressure relief cap when the engine is operating or the cooling system is hot. The cooling system is under pressure; steam and hot liquid can come out forcefully when the cap is loosened slightly. Failure to follow these instructions may result in serious personal injury.

Once pressure is released, remove the pressure relief cap/radiator cap.

2. Drain the cooling system. For additional information, refer to Cooling System Draining, Filling and Bleeding Cooling System Draining, Filling and Bleeding.

3. Remove the coolant thermostat. For additional information, refer to Thermostat - 3.7L [1][2]Service and Repair, Thermostat - 5.0L [1][2]Service and Repair or Thermostat - 5.4L (4V) [1][2]Service and Repair.

4. Install the coolant hose connection without the thermostat.

5. NOTE: Refer to the cooling system flusher manufacturer's operating instructions for specific vehicle hook-up.

Using an appropriate cooling system flusher, flush the engine and radiator. Use Motorcraft(R) Premium Cooling System Flush and follow the directions on the packaging.

6. Install the thermostat. For additional information, refer to Thermostat and Thermostat Housing - Exploded View Thermostat and Thermostat Housing - Exploded View and Thermostat - 3.7L [1][2]Service and Repair, Thermostat - 5.0L [1][2]Service and Repair or Thermostat - 5.4L (4V) [1][2]Service and Repair.

7. Backflush the heater core. For additional information, refer to Heater Core Backflushing Heater Core Backflushing.

8. Fill and bleed the cooling system. For additional information, refer to Cooling System Draining, Filling and Bleeding Cooling System Draining, Filling and Bleeding.