Water pump or other leak in coolant system?

I have a 99 XJ 4.0L and I have just replaced the water pump with a reman'd unit in late Oct 06.

In the last 4 days, I have noticed that there has been a leak, coolant dripping from the front of the engine and I have not been able to locate the exact source of the leak. I have seen that coolant is coming from somewhere around the bottom of the water pump, it flows down the bottom of the lower rad hose and drips down to the ground from there.

Now, this leak only happens when the engine warms up and the system is pressured up. If I start the engine and let it idle, there is no leak. If I drive around for a few minutes, the leak starts again.

I pulled off the lower rad hose and I can see no stresses in the hose. I put in a new hose anyway, at 336,XXXkm, what would be the harm.

The water pump should be fine, considering it is only 5 months old, but parts have been know to be defective. I assume that if the water pump was gone, then coolant should leak out of the weeping hole upon starting up the engine before it gets pressured up, am I right, or I am wrong? Let me know your thoughts and experiences...

no expert here, but i had the same problem! i bought a reman'd pump and after intstalling it about a month ago, it leaked on me and dripped down to the base of the lower rad. hose. now i have a V6 2.8L '84 so some stuff is different, but the overall purpose, and general setup of the cooling system (at least in a general sense, in reference to the water pump) is the same.

i couldn't figure it out, and the weep hole was the first thing i suspected. the only things that i can guess is that either 1) the surface that makes contact with the gasket was scored (therefore no good seal), 2) possibly the cross threading of bolts, and 3) leaky hose connections.

i dont know if there is a history with bad reman'd pumps or what but i find it weird that we had the same problem.

my solution: I watched it drip for a couple days (with no major changes in coolant level), tightened up the worm clamps holding my hoses, and figured that i probably cross threaded a bolt somewhere (all the bolts for the pump were unusually thought to get out/put back in...which is how i reached that conclusion). I simply threw in a bottle/dose of radiator stop leak and viola! no more leak.

sorry for the long-winded explanation, let me know how things work out, again im no expert (far from it) and would just like to know if i really fixed the prob, and what to look out for. cheers, Ed

Let's see, you had water pump work done in recent months and now see coolant dripping from bottom of water pump? Lemme guess, something's wrong with the water pump and/or installation of same.

I trust old used parts with a track record more than I do anything new ya bring home the store. As long as it's within spec, I'll take the part that I know already has 10k miles of hot/cold & vibration on it over the same part that's been sitting on a shelf in a comfortable box.

Obviously, that doesn't work for water pumps or something similar but when you have problem in area of worked recently performed, it's a good idea to go back over the work performed and make certain everything is 100%.

I'd suspect the pipe nipple connection for the upper heater hose for one thing.
You can see that up top, but if its just weeping it can be hard to tell.

I would drive around till it leaked, then shut the engine off and wipe up the drips with a rag. Then start the engine back up and see where its coming from. My 2¢ is on the gasket....

Yea those gasket are a pain. I just use form a gasket on mine no problem after that good luck:doh:

It turned out that the water pump I had failed after only 5 months and about 2000 miles. I took off the water pump and there was a stain of coolant coming out of the weep hole. I put in a new w/p in B.C. and returned the old one in A.B. and I actually got my cash back for the old one! Shocking...

It turned out that the water pump I had failed after only 5 months and about 2000 miles. I took off the water pump and there was a stain of coolant coming out of the weep hole. I put in a new w/p in B.C. and returned the old one in A.B. and I actually got my cash back for the old one! Shocking...

I had the same thing happen to me on the wifes 96, the pump lasted 7 months.

good on you for catching that. I want to point out that the radiators can develop leaks where the plastic tank is crimped to the metal radiator. I had a leak there and chased it around for weaks until I came to the conclusion that the radiator was the culprit. Just a little something to watch out for.

I think i might be having a problem with my waterpump. I am trying to figure out exactly where the problem is originating from, it seems to be coming from underneath the waterpump somewhere, where is the weep hole that a few people have talked about??? I think my pump might just be old. My 96 has 109k miles.
Thanks,

PBen

I bought a new pump. Used the regular gasket, but put a light coating of RTV on either side of the gasket.

works.

the water pumps are designed to leak out of a weep hole on the bottom when they quit working, so I'd guess that's it..

Also, if you've overheated, ive seen the thermostat housing leak from being warped, happened on my old xj, if thats the case, good luck gettin the new one to fit... but it CAN be done!!