2000 Jeep Grand Cherokee 4.0. The water pump I pulled off had shattered plastic fins (see https://www.cherokeeforum.com/f5/pic...mp-oem-178188/). Got a new AC Delco with cast-iron impeller replacement pump.

Problem reinstalling the metal heater pipe onto the water pump: the pipe screws in, then "bottoms out" while facing the 180 deg wrong direction on the pump. I have torqued it "back and forth" trying the get the threads deeper, but hard to get good leverage with the part off the vehicle. Therefore, I have packed the threads with red RTV, and am allowing it to cure 180 deg "backed off" from the tight position. Seems like a cheezy way to do it.

1) Will this hold once cured?
2) How does the RTV cure if air cant get to it? After all, it does not self-cure in the tube it comes in...

Thanks,
JohnEP

 

I installed mine before I put the pump on, it was tough but I got it torqued on facing the right way. Been on there for over a year now. Its on an XJ but same 4.0.

 

Two options.

1. Use a ton of Teflon Tape. Thread it in all the way and back off to where you need it.

2. (I prefer this option) Replace the pipe with a nipple fitting, tighten it all the way down and run the heater hose all the way down to it. Completely eliminate the pipe.

 

Wow I love option 2 I will be doing that on next water pump that gets replaced.

 

I like #2 as well. Any idea what size the threads are for the nipple fitting and where to find one locally?

Even so, I'll let my RTV cure tonight, then test the joint for stability tomorrow.
Bump: Anyone know how red RTV "cures" without air?

 

Compliments of djb383(wherever he may be):


Ours was so rusty, didn't even attempt to remove it, figured I'd end up with a broken stub in the water pump.......replaced the pump and used a brass 3/8" NPT X 5/8" hose barb nipple. Cheaper than the factory steel pipe and will never rust.
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RTV cures by absorbing moisture.

 

Thanks for the good info. The red RTV packed into the threads of the original pipe seems to be holding surprisingly well. Location makes it easy to see any futures drips (if they should develop). Risk of catastrophic coolant loss seems minimal: no way for that bent metal hose to spin off. Will replace with brass nipple if any future problem develops.