Gasket sealer is not necessary. I've been replacing them for over 10 years
without sealer and have had no problems. The top gasket will come with a
sealing strip on it, that should be enough. If you do want to use sealer, it
won't hurt. I strongly recommend a non-hardening type sealer. Anything that
seals permanently will cause a serious headache the next time you try to
renew the thing.

The biggest thing to be careful with is the installation of the face seal,
the rubber seal that goes on top of the housing. Push it on too tight and
the seal will come apart from rubbing on the housing. If it is too loose it
won't do the job. Both problems can lead to high speed overheating. MercC
has a little plastic installer for the seal that sets the height just right.
Be sure to use it.


wrote in message ...
Thanks to all who gave me some good advice on replacing the impeller
in my Merc water pump. Some previous post's I read said to use some
sort of gasket seal when replacing the old gaskets. I asked the
service dept. at the shop I use what kind I needed and he said you
don't have to use any. Now, I'm confused, I thought gasket seal was
always needed when replacing gaskets on anything. Yea, or nay.
Thanks,
HJJ