The water pump is the heart of the Ford Windstar's cooling system; and if it goes bad, it can cause more problems than just overheating. Continued overheating will take a toll on your engine and cause severe damage, such as a blown head gasket. If you hear any noise coming from the water pump when the motor is running or if you see it leaking around the pump, then chances are the bearing is shot, and you need to replace it.
Wait for the engine to cool down then disconnect the negative battery cable with a wrench to loosen the nut on the terminal.
Drain the coolant into a container by opening the drain valve on the bottom of the radiator. The valve is a butterfly type that can be opened by hand. If the coolant is clean, you can re-use it.
Loosen the alternator with the proper-sized socket and ratchet enough so that you can push it towards the rear of the van. Remove the accessory drive belt when done.
Remove the water pump pulley with the proper-sized wrench.
Detach the drive belt tensioner with the socket and ratchet.
Remove the lower radiator and heater hose from the water pump with a flat head screwdriver to loosen the clamps.
Unscrew the bolts from the water pump with the socket and ratchet then pull it away from the engine.
Clean the old gasket away from the water pump mounting surface with a scraper.
Place a new gasket on the water pump mounting surface using gasket sealant to hold it in place.
Install the water pump pulley onto the pump then set it on the water pump mounting surface.
Secure the mounting bolts onto the water pump and tighten them snugly with the socket and ratchet.
Hand-tighten the water pump pulley bolts.
Reinstall the automatic belt tensioner and tighten the retaining nuts with the socket and ratchet.
Install the accessory belts and pull the alternator towards the front of the van to pull the belts tight. Tighten the alternator with the socket. Refer to the belt routing diagram on the fan shroud if necessary.
Tighten the water pump pulley bolts with the socket.
Reconnect the radiator and heater hoses to the water pump and tighten the clamps with the screwdriver.
Refill the engine coolant system.
Reconnect the negative battery terminal and start the engine. Check for any leaks.
