Replacing Your Jeep Waterpump

(Main Photo) The large photo above is looking up at the engine from the front of the Jeep. Coolant can be seen dripping from the front edge of the oil pan just behind the crankshaft pulley.


Weep hole - when your water pump goes bad, coolant will seep out of this hole.
This is what the water pump looks like as if it were mounted on the engine. If you've ever seen a 97-99 water pump, you'll know that it doesn't look like this.
Pic of the Serpentine Belt/Pulley System on a 4.0L - 2000+ TJ. Notice the Automatic Tensioning Pulley.
This is what a Fan Wrench looks like. You can pick one up from most any autoparts store for about $5.
Place your Fan Wrench on the fan nut and give it a slight tap or two, counter-click wise with a hammer.

Replacing Your Waterpump
(2000+ Jeep TJ with 4.0L Engine)

What a total PITA!! At least that is if you're like me, an owner of a 2000+ TJ, with a bad water pump and out of warranty. Apparently, What should have only cost about $34 wound up costing me a little over $120 and all because DC decided to change the design of the water pump and layout of the serpentine belt in 2000+ model TJ's with 4.0L engines. Unfortunately, all the local autopart stores still indicate in their computers that the previous pump (1997-99) is what should be used in a 2000, but I can tell you first hand that it doesn't! I tried getting a pump for an 01 or newer but wouldn't you know it, they don't stock 01's or newer yet! Needless to say, I needed this part ASAP and therefore went to the dealer, who did in fact have the correct pump and allowed myself to get screwed to the tune of $120+ tax. Anyway, I hope by the time you need to do this job, the part is available (with a lifetime warranty like it should have) at your local parts store and that this write-up will be of use to you.

What You Will Need

• New Water pump - Mopar $120
(if aftermarket available - $34)
• Standard Tool Set
• Fan Wrench
• Strap Wrench
• Hose Clamp Tool or Large Channel-Locks
• Bucket
• Anti-Freeze
• Distilled Water
• Teflon Tape
• Permatex Gasket Remover

Installation

1. Disconnect the negative battery cable.

2. Drain the cooling system into a bucket by opening the valve located on bottom of the radiator.

3. Disconnect the overflow hose from the radiator and then remove the reservoir bottle.

4. Disconnect the upper and lower hoses from the radiator using a hose clamp tool or large channel-locks and disconnect the heater hose.

5. Unbolt the fan shroud from the radiator

6. Place your fan wrench on the fan nut and give it a slight tap or two, counter-click wise with a hammer. This should be enough to loosen the nut so that it can be screwed off by hand. Be careful as you approach the end and slowly pull both the fan and shroud off together. Be mindful of the radiator as you do not want to damage it by accidentally bumping into it with anything. Also, unless you are planning to replace the fan clutch at this time, be sure to set the fan in an upright position and NOT lying down. Lying the fan clutch down horizontally will cause the silicon fluid to drain into the bearing assembly and contaminate the lubricant.

7. Remove the serpentine belt by pushing down on the automatic tensioning pulley and then sliding it off. To do this, simply take a 1/2 drive ratchet (no socket attached), stick it in the square hole, and use the ratchet as your lever to apply pressure to loosen the tension on the belt. If you do not have the original diagram on the radiator showing the routing of your belt, be sure to draw a diagram of it first.

8. Using a strap wrench to hold the water pump pulley wheel in place, remove the four bolts holding it on and then un-bolt the water pump from the engine block.

9. Stuff a clean rag into the hole in the engine to prevent any debris from getting in and then carefully proceed to scrape off all the gasket material from the engine block. If you spray it with some gasket remover ahead of time, it will make the job a lot easier. Take you time at this as you won't want to have to re-do it.

10. Disconnect the heater hose fitting from the top of the old pump as well as the bottom radiator hose. Clean the threads and apply some teflon tape to the heater hose fitting and then install it on the new pump. Be sure to take note which direction it needs to be facing.

11. If you are replacing your radiator hoses, do it at this time or if they are still in good shape, re-install the bottom radiator hose onto the new water pump

12. The new water pump should come with it's own gasket that has a silicon bead. DO NOT use any RTV but be sure to have the silicon bead facing the pump when installing the pump and then evenly torque the bolts on at 200 in. lbs. (17 ft. lbs.) Rotate the shaft by hand to make sure it turns freely.

13. Re-install the pulley wheel onto the waterpump using a strap wrench again to hold it in place and then re-install the heater hose.

14. Re-install your serpentine belt (I decided to install a new serpentine belt at this time) being careful to route it exactly the way it was on before leaving the automatic tensioning pulley last. Using a large flat-head screw driver placed in a groove on the pulley arm, I depressed it until I could slide on the belt.

15. Carefully re-install your fan and shroud.

16. Re-connect the upper and lower radiator hoses as well as the overflow bottle.

17. Refill your cooling system, re-connect your negative battery cable, start your engine and then check for leaks.

I think I've covered all the bases but if you have any questions, please e-mail me. If you don't already have one, an FSM (factory service manual) of you're exact make and year is something every Jeep owner should have.