Well, my pump started leaking. And my warranty has just recently run out (I'm now at 37K). So I decided to replace it. For the record, I am not a mechanic. I'm just explaining how I did this. If you follow my directions and have a bad outcome, it would be similar to following a mechanic's instructions on how to perform cardiac bypass. I'm just giving everyone an idea of what is involved.
First, I had to find a place that had the pump. Everywhere I looked they were remanufactured, so I ended up getting one from Advance Auto.
Start by draining the radiator of coolant. On the bottom of the passenger side of the radiator there is a small plastic screw that cannot be turned by hand apparently. It has a small spout under it. I attached a piece of tubing that I had laying around because the engineers at Jeep put a small crossmember and some wiring directly below the spout. I wanted to make less of a mess.

Then isolate the water pump. It is the pulley in the middle with the non-ribbed side of the belt coursing around it.

Take the serpentine belt off by putting a 3/8" rachet into the square hole on the belt tensioner pulley on the left of this picture. Once the belt is off, inspect it for damage, cracks, and other problems and replace it as needed. After the belt is off, you can take off the cover of the pulley itself. It has three bolts (red arrow), and they are 13mm. However, you also need a phillips screwdriver to put through the little holes(yellow arrow) to hole it in place while you turn those bolts.

After it comes off, there are 7 10mm bolts that hold the pump in place. I don't have a picture of this step, but some are marked in green on this picture.

Once they are all loose, pull straight forward. Have a bucket under the front of the engine block, as there will be plenty of coolant coming out that didn't come out of the radiator. Here is what the old one will look like on the ground.

Then, spend some time cleaning the old gasket off the block. I used a razor blade. Don't use a screwdriver or chisel, as you might gouge the metal and make it impossible for the gasket to seal, thus making it leak still.

Put the new gasket (some people put sealant here, some don't. Follow the directions of your particular gasket is all I can tell you) on the new pump. Finger start all the bolts, then crank them all down slowly so as not to warp the pump. The manual state to crank them down to 12 N*m or 105 in-lbs (8.75ft-lbs). Then attach the pulley assembly using 28 N*m or 250 in-lbs (20.8333) as the tension on the bolts. Put the serpentine belt back on the same way you took it off.
Refill with antifreeze. I used this opportunity to put new in as I didn't really put the old in a clean container. Fill up to the top, then run it, topping off as needed. Eventually all the air bubbles will come out. Now you have a shiny new water pump that doesn't leak on your floor.

 

I thought you said you are not a mechanic. Sure looks like you are to me.
One detail I would add is make sure to add 50/50 mix of antifreeze and distilled water. The safest bet is use the same kind that was in there before.

 

As Ron said.
Antifreeze/Water in a 50/50 to 70/30 ratio (70/30 for extreme environments).
If you can't find the red stuff Jeep uses, you can use the "safe for all cars" version they sell at your local stores. Just make sure it says it can mix with everything.
You could also use this opportunity to flush your system, but I didn't do this.



For the record, you want to replace the pump before you lift your Jeep if you have the opportunity. Or you will spend a lot of time kneeling on your bumper trying to do this.

 

Great write up Doc. I thought there would be a lot more to it, but after seeing your write up it doesn't look too bad at all. What did the water pump run you at the parts store?

 

$39 plus $10 core.
All in all only took a couple hours, counting drainage time (around 1.5 gallons), and riding my bike to the store to get the part and antifreeze.

 

Wow, that's not too hard on the wallet either.... Thanks again for the write up.

 

Good write up bro> I just did mine with 45k on the motor....seems a bit early right?

 

The water pump on my XJ was still good at 186K when I sold it.

 

When I changed the water pump on my Tundra (which totally blew in that you have to pull off the timing belt to do it), there were drains on either side of the block that allowed for a completely drained system. Does the 3.8 have a block drain?

 

Thanks for the write up. I'm glad there is so little involved.