Your car's cooling system keeps the engine from overheating. The water pump is the center of the cooling system. When the pump leaks or otherwise stops working properly, the cooling system can’t do its job. Buying a new water pump can be costly. If you have some skill at working on cars, you can bypass much of that cost by buying the needed parts, taking the water pump apart yourself and rebuilding it.
Wait until the car’s engine is completely cooled off. Open the hood and disconnect the battery. Place the drain pan under the radiator and drain the coolant from the radiator into the drain pan.
Loosen the belts and remove the water pump, following the instructions of your car's owner's manual.
Use a wrench or a screwdriver to remove the bolts or screws that fasten the pump’s rear plate to the bottom of the pump.
Press the shaft out of the hub. It may come out easily or you might have to support the hub in a hydraulic press and press out the shaft with a press bar. Inspect the shaft for any damage. If it is undamaged, put it aside.
Remove the bearings and rings. Depending on your pump, you might have to press some of the bearings out from the inside of the pump. Use pliers to remove the inner gasket.
Remove the old gasket material with a wire brush. Clean the mounting surfaces on the car’s engine block. Clean the water pump housing with a sandblaster. Check the clean housing for any cracks.
Put the new bearings into place. Use a well socket to press the shaft with the new bearings back into place, making sure to put the grooved end into the housing. When assembled correctly, the bearings and shaft are flush with the pump housing.
Lubricate the new gaskets and rings with gasket sealant and snap or put them into place. Replace the small outer seal and the snap ring.
Immerse the pump in a bucket of water for at least an hour to make sure there are no leaks.
Either screw or bolt the back plate back on. The pump is now rebuilt and ready to be installed back into your car.
