A bad water pump on a Ford 5.0-liter engine will be indicated by water pump bearing noise or leakage of coolant from the water pump. Bad water pump bearings can be verified by removing the accessory belt and pulling the fan up and down to feel play in the water pump bearings. Leakage of coolant from the water pump can be observed anywhere the water pump mounts to the engine, along the water pump's front seal, and around the drain hole on the bottom of the water pump. If any signs of leaking coolant are visible in these areas, the water pump needs to be replaced.
Drain the radiator when the engine is cool. Place a drain pan under the radiator drain plug. The drain plug is on the bottom left side of the radiator and can be loosened by hand by turning the plug counterclockwise.
Close and hand-tighten the radiator drain plug.
Remove the accessory drive belt from the water pump pulley. The belt can be removed by releasing belt tension at the belt tensioner with a wrench and sliding the belt off the pulley. You should see a diagram in the engine compartment showing how the belt is installed and where the belt tensioner is located.
Remove the fan and water pump pulley from the water pump. They are mounted to the water pump with four bolts that can be removed by loosening counterclockwise with a wrench.
Remove the bracket mounting the air conditioner compressor and power steering pump to the engine. The bracket is connected to the engine with two bolts. Remove the bolts by turning counterclockwise with a socket. Pull the bracket with the attached air conditioner compressor and power steering pump off the water pump studs. Move the assembly off to the side for easy access to the water pump mounting bolts.
Disconnect all hoses from the water pump. Look for a lower radiator hose, heater hose and bypass hose. Loosen each hose clamp with a flat-head screwdriver and pull the hoses off the water pump.
Remove all bolts mounting the water pump to the engine block. Keep track of where the different sizes and shapes of hardware were removed for later reassembly.
Scrape any residue of the old water pump gasket and sealant from the water pump mounting surfaces on the engine block.
Apply a thin layer of thermostat and water pump gasket sealer to both sides of the new water pump gasket.
Align the gasket to the replacement water pump and install with all mounting hardware. Finger-tighten.
Torque all water pump mounting bolts 12 to 14 foot-pounds.
Reconnect the lower radiator hose, heater hose and bypass hose to the water pump. Secure the hose clamps.
Place the air conditioner compressor and power steering pump bracket with attached accessories back on the water pump studs. Reattach to the engine with the two bolts.
Place the disconnected accessory drive belt back over the top of the new water pump.
Reconnect the water pump pulley and fan to the water pump with the four bolts.
Reinstall the accessory drive belt according to diagram in the engine compartment.
Remove the radiator cap and refill the radiator with a 50 percent antifreeze and 50 percent water mixture or as otherwise directed by your Ford owner's manual.
Leave the radiator cap off and start the engine. Continue filling the radiator as the coolant circulates through the cooling system.
When the coolant level stabilizes at full, close and hand-tighten the radiator cap.
Inspect the water pump and water pump hoses for leaks.
Turn off the vehicle.
Check coolant level daily over the next few weeks of operation.
