When engine coolant or water leaves the radiator, it passes through a filtration system to help eliminate minor contaminants. The coolant is then fed through the water pump, which supplies the engine block with coolant, allowing it to operate at an efficient temperature. The Ford Fusion water pump is a traditional, belt-driven system operated by a pulley.
Park the vehicle on level ground and engage the parking brake for safety. Remove the battery access cover and disconnect the negative (-) battery cable. Let the vehicle cool off for at least 30 minutes after driving.
Use the socket wrench to disconnect the bolts from the front underneath splash guard. Remove the splash guard and set aside; keep the hardware in a safe place.
Place the drain pan under the radiator and drain the engine coolant. Detach the coolant reservoir and set aside.
Remove the three bolts mounting the water pump pulley to remove it. Set the drive belt aside. Remove the three bolts mounting the water pump and the O-ring gasket. Discard the used O-ring gasket.
Clean the area the water pump was attached to the engine thoroughly with the towel. A cleaning solution is not needed.
Attach the new O-ring, followed by the water pump. Tighten the water pump bolts with the torque wrench to between 71 to 101-inch pounds.
Attach the water pump pulley and use the torque wrench to tighten the bolts to between 12 and 17 foot-pounds. Place the belt back around the water pump pulley.
Remount the coolant reservoir and the front underneath guard with the socket wrench. Reattach the negative (-) battery cable and the battery cover.
Inspect the used coolant before putting it back in the vehicle. Engine coolant should be light green and free of debris. If the coolant is contaminated, check with your local waste authority for disposal options. Refill the vehicle with clean coolant.
This procedure will also apply to the 2003 to 2008 Mazda 6, which shares an engine with the Fusion.
Do not attempt this procedure without a torque wrench. Improperly tightened bolts can cause leaks within your cooling system, possibly causing long-term damage.