Produced from 1998 to early 2003, the Ford 7.3 turbo diesel has a well-known reputation for being a workhorse. The large diesel engine's abilities range from hauling luxury fifth-wheel travel trailers to getting down and dirty on the muddy road to a remote oil rig. These kinds of demands require that you maintain your engine on a regular basis. A puddle of coolant underneath your truck is a good indication that a water pump replacement is in your future.
Loosen the coolant reservoir cap. Place a drain pan under the left side of the radiator and loosen the radiator drain petcock. Retighten the drain petcock after all of the coolant has drained from the radiator. Remove the lug wrench from the top of the radiator. Remove the attaching bolts from the coolant reservoir tank. Disconnect the upper coolant hose and the lower radiator hose from the coolant tank. Remove the coolant tank from the engine bay.
Loosen the large nut attaching the fan to the water pump pulley, using the fan nut wrench to turn the nut counterclockwise. Remove the upper radiator hose and the bolts holding the fan shroud. Lift the fan shroud and the fan assembly together out of the engine bay and set aside.
Loosen but do not remove the four bolts holding the water pump pulley. Use a 3/8-inch drive ratchet wrench to relieve the pressure on the belt tensioner and remove the serpentine belt. Finish backing out the four pulley bolts and remove the pulley. Remove the camshaft and coolant sensor wiring plugs and move them aside. Remove the four bolts holding the upper coolant hose onto the water pump. Remove the clamp holding the heater hose onto the water pump and remove the hose.
Loosen and remove the nine attaching bolts from the water pump and remove the water pump from the engine bay. Remove the coolant temperature sensor and the thermostat from the old water pump and install them onto the new water pump using thread sealant. Install the metal coolant tube onto the new water pump. Install the “O” ring onto the back of the water pump and apply sealant.
Reattach the new water pump to the engine block using the nine attaching bolts. Reconnect the heater hose, upper radiator hose, and the coolant and camshaft sensor plugs. Install the water pump pulley, leaving the four attaching bolts loose. Reinstall the serpentine belt and tighten the four pulley bolts. Lift the fan shroud and fan into the engine bay. Reattach the fan shroud bolts. Using the fan nut wrench, reattach the fan to the water pump pulley.
Reinstall the coolant tank and upper and lower radiator hoses. Remove the cap from the coolant tank and add 4 gallons of antifreeze, 4 gallons of distilled water, and one bottle of coolant conditioner. Screw the cap back onto the coolant tank and start the engine. Allow engine to run a few minutes and check for leaks. Tighten any connections as needed. Add more coolant if the level is not between the minimum and maximum marks on the coolant tank.
