[help] Large water leak after replacing w/p...

I must be doing something stupid, but I'm not sure what. I replaced the waterpump on my '91 4.0L and now when I fill the radiator, I get water pouring out from a location just below the waterpump. It almost looks like it's seeping out a hole just below and next to the lower waterpump bolt, but I can't quite see with it all together.

I pulled everything apart (and did the front main seal too this time) and put it all back together giving the silicone and gaskets on the w/p & t-stat housing a solid 24 hours to cure. Put water in and same thing happens. It's enough water that it looks like it's pouring from somewhere, not just a small seeping. I've got all the bolts and brackets back on but still this large leak. Any ideas?!?!?

R
'91Limited

Are you sure its not seeping from the weep hole on the water pump? Maybe you got a bad one. I know its hard to see up under there, especially when there's antifreeze running down your face.

AZRuss said:

I must be doing something stupid, but I'm not sure what. I replaced the waterpump on my '91 4.0L and now when I fill the radiator, I get water pouring out from a location just below the waterpump. It almost looks like it's seeping out a hole just below and next to the lower waterpump bolt, but I can't quite see with it all together.

I pulled everything apart (and did the front main seal too this time) and put it all back together giving the silicone and gaskets on the w/p & t-stat housing a solid 24 hours to cure. Put water in and same thing happens. It's enough water that it looks like it's pouring from somewhere, not just a small seeping. I've got all the bolts and brackets back on but still this large leak. Any ideas?!?!?

R
'91Limited

Click to expand...

You got something wrong big-time. I can't see dick from my computer screen but you'd better get a strong light and mirror and figure out what it is.

When doing the pump the surfaces have to be clean, DRY and prepped before you put the pump on. I had to take mine apart as it was leaking out the same spot you are describing. I put indian head gasket cement on both sides of the gasket, put the pump straight in [after I moved the PS pump bracket out of the way on the second try] started the bolts in [except the PS pump bracket ones] and snugged them down, then I torqued them to 22ft lbs, move the PS bracket back to where it was supposed to be and put in the other two bolts. Then before did anything else I filled the system. It started to dribble so I quickly torqued the bolts to 24ft lbs and it stopped. Then I reinstalled the one bolt that keeps the PS bracket on my 98 attached to the block and reassembled everything but did not put the electric fan back in, set that on the floor in the cellar and fired up the engine. Let it warm up and checked for leaks.
Oh, the SECOND time I used a baster to pull all the remaining water out from around the cylinders in that big hole where the pump goes and then dried the area with lots of rags.

AZRuss, your not alone! I thought I screwed somthing up the other night doing the same thing. Went to fill it up and was leaking out as much as before. I guess I didnt line up the gasket correctly when trying to get it in place. Had to remove everything and go buy another gasket at Advance. Looked to be a little better than the orginal. Took my time and made sure the P/S was well out of the way and made sure it sat flat on the block. Just make sure the gasket is sitting the right way. ONe way, its close, other way, its perfect. If it sits backwards the one hole on top of pump doesnt line up right and it will spew out when filling. Good luck.

Thanks for all the prompt replies. I'm pretty sure I got the gasket and pump on correctly and tight and I used some RTV sealant as well on both sides of the gasket.

I'm wondering if Bradlybob is right about the weep hole. Tomorrow morning I may get the change to pull the belt and PS pump back out of the way and get a better look. This time I'm not putting all that crap back on until I test fill the system (should have done that this morning).

Thanks again for the help and I'll post again with what I find.
R
'91Limited

AZRuss said:

Thanks for all the prompt replies. I'm pretty sure I got the gasket and pump on correctly and tight and I used some RTV sealant as well on both sides of the gasket.

I'm wondering if Bradlybob is right about the weep hole. Tomorrow morning I may get the change to pull the belt and PS pump back out of the way and get a better look. This time I'm not putting all that crap back on until I test fill the system (should have done that this morning).

Thanks again for the help and I'll post again with what I find.
R
'91Limited

Click to expand...

Don't like RTV, never have, never will, indian head does a better job on cooling systems.

A few causes, as others mentioned.

1. Defective water pump
2. WP gasket not installed correctly, slipped, tore
3. Lower radiator hose clamp not tight, or the hose has a leak at the clamp
4. T-stat not installed flush, thus leaving a gap under the housing
5. Leak from heater pipe (threads not sealed)

My 2 _Maz

Re: Need aftermarket trans oil cooler suggestions (w/p leak fixed)...

OK BradlyBob had it right. The waterpump I installed was leaking through the lower weep hole. I swapped it out for another new one and the leak is gone.

Problem now is that the upper trans cooling line is cracked and leaking. Oh well, I was going to replace it and install an aftermarket tran oil cooler soon anyway. I don't plan on doing any towing and my off-roading is maybe once a month and moderate, but I am in Phoenix so 120 degree outside temps are upon us for summer.

Are there any recommended oil coolers to use? I was planning on just going with something medium duty and cheap from Checker or Autozone unless you guys have other recommendations.

Thanks,
R

nevermind on the trans oil cooler...

OK, I've been up for 23 hours and apparently didn't see the Search item above. I've found some good stuff for suggestions on oil coolers. I'll read up and then see whether or not I'm going to bypass the radiator all together or go through both.

Thanks again for all the help!
R

i did mine this weekend, took me 2 tries and one try i had to try twice! my problem was i didn't clean the old gasket off the block good enough... second try i used a razor and there was more gasket than i could actualy see... i wish i took more time the first 6 hour attempt to get this. also, it will help for future work to replace the hose clamps with the ones that use a screw driver to tighten, its hard to get your hands in there with large tools. i'm convinced this project was way harder then i anticipated, but the expierence is good... 1 water pump, 4 gals of coolant, 2 gaskets, 1 broken shrowd, 2 attempts, 12 hours and 100 + bucks later, it works!

how much would a shop charge to do this job?

ok im gearing up to do mine this week

regarding the gasket, what is the best way to do it? RTV, paper gasket, paper gasket and rtv on both sides? etc....

so about 4 gallons of coolant? for a 98

your new pump will come with a gasket (and maybe a small tube of sealant.)
Usually if you put anything on the gasket it should be a thin tacky gasket dressing (not RTV). Of course if the install directions say otherwise I'd go by that.

When I did mine, I used some Chrysler black silcone sealant on both sides of the gasket. I use a ver thin layer and let it dry for a good 3-4 hours before I filled the system and drove it.

R