Safe to use RTV instead of a gasket on water pump?
 

I'm installing a new water pump and the housing came off with it. I don't currently have a real gasket for the housing, just the water pump. Is it safe/advisable to use RTV instead of a gasket? If so, what kind of RTV? I have some copper lying around if that works.

This is what would be RTV'd instead of a gasket.
http://mazdatrix.com/pictures/b-water/gsk2hs2e.jpg

Permatex Blue RTV Silicone, never had a problem using this on waterpumps.

All RTV's are based off *mostly* Dow Chemical Silicone with various fillers and pigments added to differentiate the end sale product.

IF using a normal US based silicone I recommend people only use good old Dow 732 (black, clear or white) pick your color! all others are just poor copies or doctored versions of this........... if its good enough for titties its good enough for your car :)

I went away from the Dow chemical silicones long ago and use Japanese stuff, Three Bond is far superior and is what is used by the factory in Japan, its much more chemical resistant, tougher, and more durable, and its grey. Before that I used a loctite copy called 5699 ? from memory meant to be an OEM grey harder silicone as well.

You can buy Three bond 1211 at any Jap motorbike dealer typically, it is all they will use, and yes you can use it alone with no gaskets despite there being such a big gap between bolt hole spacings and thin sealing areas like on the water pump housing.

p.s. Permatex is just a retail brand of loctite meant for people who shop at LOWES? or PARTS DEPOT? etc etc. Unltra Blue, Copper etc etc ..... I generally stay away from them... yes I used to deal directly with Loctite and Dow Chemical engineers as a job so know a bit about them :)

I'll look for the Three Bond but if I can't find it I ran across this:

http://www.permatex.com/products/Aut...one_Gasket.htm

I've always used either the black or copper RTV by Permatex.
Those two are "better" and more flexible than the blue stuff.
I've had bad experiences with the blue stuff "crumbling".

3Bond basically makes all the Japanese OEM assembly stuff.
You might also know it as Hondabond / Yamabond / Mazdabond, etc.
It's sometimes difficult to get these - OEM dealers should carry them though.
...and they are MUCHU expensive versus the Permatex stuff.
Permatex RTV's are easily available at most car parts stores + WalMart, etc. and MUCH cheaper - less than $10 a tube.


-Ted

Permatex it is. I'll try to find that water pump specific one. If not I'll probably just use the Copper I have sitting around.

Isn't there a need for a gasket there? What I mean is there are the two washers on the studs to the left to keep the water pump housing level right, and not having those, or using those and not a gasket might not let the housing flange sit level with the block.

** With that said, I haven't tried it, that's just what I've heard/thought was going on. Mazdatrix mentions the housing will break without them.

Reted correct me if I'm wrong!

i like to use oem parts and the cost is the same or close it! just my 2 cents

Won't the permatex be equivalent to a gasket in regards to having the housing sit level?

You are right.
If you don't have the even pressure (stock uses the gasket + two thin shim washers) on the water pump housing to the front iron, there's a possibility you can crack off the top-most water pump housing stud "ear" on the front iron.
I've seen it countless times.

Yes, in a pinch, I've used just RTV on the mating surfaces *PLUS* the two water pump housing studs that would normally have those two thin shim washers.


-Ted

I have the two shims, just no gasket. Am I correct in assuming that it's safe to use the shims + gasket maker in the shape of the above pictured gasket?

have you talked to charles? he may have a gasket and you won't have to worry about it

If you delete the gasket and use nothing but a sealant, wouldn't it make a lot of sense to omit one or both of the adjusting spacers since there is no longer a need to fill the gap that would have been produced from the use of the gasket which is thicker than a compressed sealant. correct me if I'm wrong. Maybe I just read the post wrong, if so ignore me.

That might make sense, I'm not sure how much thinner sealant would be than a gasket. :dunno:

Somehow I missed your post and Paul's until now. I went ahead and ordered a gasket from Ray Crowe. It gave me an excuse to buy some interior parts too. :D It'll be nice having demister vent grills and an idiot light surround. Now all I need is an S5 radio surround.

Side note, Ray hooked me up bigtime. His prices were significantly lower than Mazdatrix and shipping is $10 regardless of what is being shipped.

I got black on mine right now, works fine.