What is the best sealer to use on water pump gaskets?

"The Right Stuff"

weatherstripping adheasive, form-a-gasket, high-tack, or engine paint. silicone in excess can cause more damage than you think.

Permatex "Ultra Blue" or the older Black RTV. Both are similar in physical characteristics. Both work well on engine gaskets. This is not the Blue Silicone stuff that's used as a replacement for intake end gaskets, that's much like the plain clear window caulking.

I've always used Permatex Ultra Blue myself. Never had a problem.

I use Permatex Hylomar HPF gasket dressing on one side of the gasket only, to help hold it in place during installation. It's designed to stay pliable so disassembly is easier. It's been 5 years since I installed my NEW (not rebuilt) water pump and no leaks. I also used it on the thermostat housing and valve covers. It's available at most parts stores.

As stated before, silicone RTV will cause problems, such as gasket slipping while tightening.

68stang351 said:

I've always used Permatex Ultra Blue myself. Never had a problem.

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+1

I use Gasgacinch on all gaskets that require a sealer/adhesive and have never had a leak.

+1 makes my vote four for blue RTV. Unless the sealing surfaces are all pitted and nasty, only a very thin layer is needed. any more and it will squeeze out into the cooling system.

SoCalCruising said:

"The Right Stuff"

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I agree!

http://www.accessconnect.com/images/82180.jpg

I've used ultra black, the blue, and permatex gasket/indian head gasket shellac. I like the actual shellac stuff (similar to aircraft adhesive) better because I find it easier to work with, and has less push out to clean up after.

Aviation adhesive can be found at a lot of autosupply places. Here in tx it's in o'reillys, a-line and vans. Check the smaller supply places.