1998 Jeep Grand Cherokee Change the Water Pump
Since its introduction in the early 1990s, the Jeep Grand Cherokee has become one of the top-selling SUVs in the U.S. The 1998 edition belongs to the first generation of Grand Cherokees and was offered with either a 4.0L inline six-cylinder engine or a 5.2L V8 engine that produced 220 hp. The water pump is driven by the drive belt. There are some differences between the engines as to how the water pump is changed, explained in the following steps.
 Tools Used
|New water pump|
|Acetone or lacquer thinner|
|O-ring (5.2L V8 engine only)|
 Change the Water Pump
- Disconnect the cable from the negative terminal of the battery. Drain the coolant from the system. Remove the cooling fan and shroud, drive belt and water pump pulley.
- Remove the hoses from the water pump by loosening the clamps. On the 4.0L six-cylinder engine, remove the idler pulley and the power steering pump. On the 5.2L V8 engine, remove the coolant return tube by unbolting it from the top of the engine and pulling it out of the water pump. Use pliers to remove the hose clamp on the bypass hose and remove it.
- Remove the water pump from the engine by unbolting it. The bolts are of different lengths, so record which hole each bolt is from. Clean the bolt holes and bolts.
- Check that the new pump is identical to the old one. For the 4.0L engine, remove the heater hose fitting from the old pump and, using sealant on the threads, attach it to the new pump. Also, for this engine, check that the impeller has an "R" on it to indicate reverse rotation.
- Use a gasket scraper to remove material left on the engine gasket flanges. Clean the water pump and engine gasket flanges with acetone or lacquer thinner. Apply thin coats of RTV sealant to both sides of the gasket. Carefully place the gasket on the pump and hold it in place with a couple of mounting bolts of the correct size in the right locations.
- Attach the water pump and the gasket to the engine using the correct remaining bolts and tighten them finger tight. Any accessory bracket held by the bolts should be attached at this time. Tighten the bolts using a torque wrench in one-quarter turn increments until 22 foot-pounds is reached for the 4.0L engine and 30 foot-pounds for the V8 engine. For the V8 engine, install the coolant return tube using a new O-ring. Install the hoses.
- Re-install the parts that were removed. Ensure that the drive belt is correctly routed. Check the drive belt tension. Fill the cooling system.
- Connect the cable to the negative terminal of the battery. Start the engine and check the water pump and hoses for leaks.
 Tips & Warnings
- Save the coolant you drain, if it is in good condition and you want to reuse it.
- Twist the hoses, using pliers, if you have trouble removing them from the water pump. If the hoses are damaged, deteriorated or have to be cut off, you need to replace them.
- For the 4.0L six-cylinder engine, do not disconnect the power steering pump hoses and keep the pump upright so as not to lose power steering fluid.
- On the 5.2L V8 engine, check the condition of the bypass hose and replace it if necessary.
- Do not start this work until the engine has completely cooled down.
- For the 4.0L six-cylinder engine, do not install a water pump without an "R" on the impeller. It will cause the engine to overheat.