Replacing the water pump in a Jeep Grand Cherokee before a complete failure can save you the aggravation of being left with your car pulled over to the side of the road with the hood raised, steam pouring out from under the hood and water gushing down to the ground. Not to mention an expensive engine repair if the engine is damaged by overheating. Usually the water pump will give you an indication that failure is imminent by leaking water through the weep hole on the pump or a howling sound at the front of the engine. Sometimes however, the failure is sudden and without any warning. If any of the signs of failure are noticed, I recommend replacing it immediately because it could completely fail at any time. Fortunately replacing the water pump in a Jeep Grand Cherokee is a relatively straight forward procedure. The following information applies to replacing the water pump in Jeep Grand Cherokee six-cylinder, 5.2L, 5.9L and 4.7L V8 engines.
Things You’ll Need
Replacement water pump, Replacement coolant, Socket wrench and sockets, Torque wrench, Adjustable pliers, Hose clamp pliers, A new water pump gasket, Gasket scraper, RTV sealant, Acetone or Lacquer thinner
Disconnect the negative battery cable from the battery.
Drain the cooling system. Save the coolant if it is in good condition to reuse. If the engine coolant is old or is in poor condition, replace it with the appropriate coolant mixture. Coolant can be purchased in a premixed or concentrated liquid.
It will be necessary to remove the cooling fan and shroud if mechanically or hydraulically driven. On electric cooling fans you will not have to remove them if space is adequate for the pump to be removed.
The next step is to remove the drive belts and then the water pump pulley. On six cylinder cars you will also have to remove the idler pulley. Also, on some six cylinder Jeeps you will have to remove the power steering pump because it shares some of the same bolts as the water pump. I recommend verifying this first because some only require one bolt to be removed and the power steering pump can remain in place. If the power steering pump is removed, do not open the system and keep upright to keep fluid from leaking out.
Next squeeze the tabs on the hose clamps and move the clamps back several inches on the hose away from the housing. (If the clamps are the screw strap type, loosen the screw/bolt and slide back on the hose in the same manner.) Twist and remove the hoses from the housing. If a hose is stuck, use a pair of adjustable pliers near the end and twist the hose to break the seal. If any of the hoses are deteriorated, cut them off and replace. On 5.2L/5.9L V8 engines, unbolt the coolant return tube from the top of the engine and pull it out of the water pump.
Now it is time to remove the water pump itself. Remove the bolts making note of the size of the bolt removed from each hole as they will need to be put back in the same locations by size when you install the new water pump. Detach the pump from the engine. On V8 models use pliers to reach above the water pump to release the hose clamp on the bypass hose. On six cylinder engines check the condition of the bypass hose and if necessary replace it.
Next remove all traces of the old gasket from the engine with a scraper and clean the bolt holes in the engine and the bolt treads to remove any corrosion and sealant. On six cylinder engines remove the heater hose fitting from the old pump and install it on the new pump using sealant on the treads. Clean the new water pump and the engine mating surfaces with acetone or lacquer thinner. Apply a thin coat of the RTV gasket sealant to the mating surface of the new pump then carefully mate the gasket and the pump. Next apply a thin layer of sealant to the engine side of the gasket and slip a couple of bolts through the pump mounting holds to hold the gasket in place.
Installation is basically the reverse. Attach the pump and gasket to the engine and finger tighten the bolts that were holding the gasket in place. Install the remaining bolts and any brackets taking care to reposition them. Torque the bolts to the recommended specifications. On the 5.2L and 5.9L engines, install a new O-ring on the on the coolant return tube and connect it to the water pump.
Install all of the parts that were removed to access the water pump including the idler pulley removed on the six cylinder Jeeps. Next inspect and if necessary replace the serpentine drive belt making sure it is installed as originally routed. There is usually a diagram inside the engine compartment showing the correct routing.
Refill the coolant to the system and then start the engine and allow it to reach normal operating temperature. Inspect the system for leaks. If any are detected, allow the engine to cool and tighten the hose clamps, bolts or replace the gasket and sealant or the rubber O-ring as necessary. Hopefully no leaks are detected and you will have a cooler running engine.
Auto repair can seem like an impossible task for the average car owner. However, replacing a car water pump is a relatively straight forward car repair that can be accomplished with minimal tools and experience.
Tips and Warnings
Special hose clamp pliers are available at most auto parts stores.
Always allow the engine to cool before removing the radiator cap, draining the coolant or replacing the water pump. Steam and hot engine coolant may be under pressure and their sudden release could result is serious burns.