Q: Water Pump - Dry vs Sealant?

[funcrew]

What are the pros and cons of gooping up the water pump gasket prior to installation? If recommended, what goop would be best? BTW I cleaned up the seating surface super nice with a razor blade scraper.

[DaveSmed]

There's this stuff called high tack, comes in a can similar to the one anti-seize comes in. Good stuff, makes a wicked mess. Fresh stuff isnt too bad, but the old stuff is great for making a small disaster wherever its used. Works though.

[jlevie]

If both surfaces are perfectly flat and smooth no sealant is needed. But that's seldom completely true, so a bit of sealant is a good idea. Most any auto parts house will have an elastic sealant specifically for cooling system service, which would be the best choice.

[FredK]

I like using Hylomar HPF from Permatex. It allows you to immediately put the car back into service. Not only does a little go a long way, it is around $3 at any generic auto parts store.

[makaio]

I like using Hylomar HPF from Permatex. It allows you to immediately put the car back into service. Not only does a little go a long way, it is around $3 at any generic auto parts store.

That's what I use. IMO you should at the min. put it on the water pump side and put the gasket on the water pump before installing it on the block. This will keep from pinching the gasket when installing it.

[funcrew]

Thanks to all. I ended up using a tiny $5 tube (that will last what's left of my lifetime) of a Permatex product specifically marked for use on water pumps.

[whowhatwhere]

I use Loctite 574

[rcko]

You can also use thicker gasket paper. The permatex should work fine.

[AlarmedBread]

I just used the regular gasket and no problems. :o

[MR 325]

Hylomar FTW

[Schniddy]

Any harm in using Curil K2?

[Stevie30]

RTV silicone; good up to 350 deg. F

[Madhatter]

non hardening aviation cement is what is normally used, #3. Its thick brown (looks black till you spread it, then its dark brown), kinda the consistancy of molasses. Permatex (along with others) make it and pretty much everyone i know in the industry will just chuck you a bottle of the stuff the minute you mention fitting a waterpump.

Silicone is something you never want to use anywhere near a circulatory system though. It beads when squished between surfaces so it can end up setting and floating around the cooling (or oil, if you use it there) system causing blockages. Hard setting agents should be used in place of gasket, not really combined with. Every manufacturer ive worked with has used a non setting agent to help locate the gasket in place and provide an extra layer of protection. What you use is up to you, but stay well away from a dry silicone.