Water Pump Gasket Sealant

[Chevy1966]

What's the best method of sealing a gasket for a new water pump? I don't feel too good about depending on the gasket alone without adding some sealant - what's the best stuff being used these days? Thanks!

[SkinnyG]

I've never used any sealant on water pump gaskets. They are not where these engines leak from.

If you ~do~ use a sealant, make sure you use a minimum amount, so no sealant squishes out and restricts the coolant passages.

[100%Chevy]

I've been using wheel bearing grease on them since the 60's.
Works for me.
Mike.

[70K10Hunter]

I have been using Permatex (aviation sealant) for many many yrs, paint on a thin layer on both sides and your good. this stuff has never failed me, I've been a mech for over thirty yrs.

[TrailerTrash]

Ive always used Permatex Ultra Black. just a thin coating on both sides one the gasket not even enough to squeeze out. same goes for thermostat housings and around the coolant passages on the intake manifold

[Malo83]

Originally Posted by trailertrash

ive always used permatex ultra black. Just a thin coating on both sides one the gasket not even enough to squeeze out. Same goes for thermostat housings and around the coolant passages on the intake manifold

x2

[Chevy1966]

Permatex it is - thin layer only. Been a long time since I replaced a water pump and when I did I used Permatex. Some things change so wanted to check in with the gang. Thanks very much!

[N2TRUX]

More important than the gaskets are the two bolts that go in to the water passage. If you dont seal them, they will bite your butt.

[Chevy1966]

Thanks for the tip. What's the best way to seal up these bolts - put plenty of sealant on the threads?

[N2TRUX]

Originally Posted by Chevy1966

Thanks for the tip. What's the best way to seal up these bolts - put plenty of sealant on the threads?

I used a big glob of clear silicone gasket sealer. Did the job once and went easy on the sealer. It started leaking again. The second time I globbed it on good.

Another thing I do is replace the water pump every time I pull the front off of the motor. If I'm sealing up leaks and get to the front of the block, I dont want to have to do it again because I cheaped out and didnt replace the pump.

[Chevy1966]

Sounds like great advice - I'm doin it as suggested! Thanks!!!

[BigJackDaddy]

Gaskets are used to fill imperfections between two parts. If the two surfaces are machined perfectly flat, no gasket would be necessary as there is no space between them for any fluid to travel. It is obviously cheaper for a manufacturer to use gaskets than it is to ensure every mounting surface is machined sufficiently flat to inhibit leakage. This was Harley's problem in the AMF years; Quality Control was so bad that the two bottom (crankshaft) case halves would leak at their mating seams.

With that being said: I only use Permatex, Indian Head, or any other sealant on a gasket when I really want to scrape and fight to get it back off later. A very small dab on a front-face / vertical gasket to hold in place while I align other parts maybe, or at the adjoining areas of the multiple-piece intake manifold or oil pan gaskets, but if you have to use glue and a gasket, something is wrong.

Alternatively, and very much like Mike's use of wheel bearing grease, coat both sides of your gaskets with anti-seize. They won't leak and they'll lift right off after years of use... no scraping required. Also coat the radiator and thermostat water necks with the same stuff before installing/re-installing hoses to prevent them from baking on over time.

[Chevy1966]

Hey BigJack... thanks for your feedback. I am totally in agreement regarding your point about the precision of the mating surfaces. Unfortunately I do not count on this level of quality from the parts made today. I had never thought about anti-seize as a sealant, but it does make sense. I'm going with Permatex this time as I believe the next swap of the water pump will coincide with a complete engine tear down and overhaul. You made some great points - thanks!

[Bandit130]

Many years ago, I have made a gasket from thin cardboard from a cereal box and spread thin film of grease on both sides. Worked Great!!!...LOL

[v30crewcab]

I use grey RTV. its pretty much the same as hondabond, that honda uses on car and motorcycle transmission cases, with no other gasket in between. it works well.