Thermostat Gasket

[Oren09]

Hey all.
I have a leaking thermostat gasket.. again.
I've replaced it three times and they all eventually start leaking.
I've been using the standard paper gasket with adhesive on one side.
The last time I replaced it, I used a fine grit sandpaper on both mounting surfaces but this didn't help very much.

Does anyone know of a really good gasket or tips to make a good seal?

[hodginsa]

Put a really thin layer on both sides and finger tighten, wait for it to turn rubbery then do the final torque.

[stonemaster]

gaskacinch or threebond

[TominMO]

Put a really thin layer on both sides and finger tighten, wait for it to turn rubbery then do the final torque.

And then let the gasket sealer cure overnight before driving it.

[Flyin4stroke]

Don't fill the system till its completely dry like ^ Tom said.

[gauge_half_inch]

Go to Toyota ask the parts counter for some "black F.I.P.G" its their special version of RTV. It is kinda expensive, but out of all the sealants I have used in my career and personal uses, it is hands down the best sealant I have ever used. It is tacky in 15 mins, just enough to put it all back together. Its fully cured in less than an hour. it remains semi flexible, but has really good adhesion. Normally, I normally start adding coolant back in as soon as I get everything tight. Never have any leaks. It's also good for oil, i.e oil pans...

[WmWatt]

Is there something wrong with the thermostat? Does it seat properly?

[crazyrog17]

I tried using the adhesive gaskets twice, both failed. Autozone sells one without adhesive with a rubberized inner lip. I put a thin layer of gasket sealer on both sides, not a drop of trouble since.

[Oren09]

So I use the gasket sealer with the gasket?
Im pretty sure my thermostat is seated and oriented properly.

[gauge_half_inch]

I never use a gasket with the F.I.P.G.

[Movin]

Wow, all excellent advise and good opinions of product. I know you know this but
to clarify some details..
sand the gasket surface of the housing on a flat surface until you can see that the
housing surface is free of pits and is flat.
rinse the block and housing with carb cleaner or equivalent, lift the drivers side
of the car a little to ensure no coolant seeps out and stains your rinse with cleaner.
when dry, this will leave a bondable surface for your choice of sealant. make sure
your bolt holes are clean. Wire wheel the bolts and put a little liquid Teflon on them.
Silicone is fine too. What ever you use just make sure it says low odor or sensor safe.
The only kind I let dry slightly before final torque is the gear box silicone. If a gasket
is used I use the sealant only on the inside edge so that part of the gasket is dry,
this keeps the gasket from pushing out. A fully coated gasket is like trying to hang
on to a salmon and clean it while still at sea!

[bravekozak]

RTV stands for "room temperature vulcanizing"

[Bert]

Wow! And no one has mentioned anything about 'slipped out of position' thermostats while the installation process is underway.
I've used ordinary silicone in squeeze tubes ever since the stuff became common 30 years ago. Haven't used gaskets in many applications for years, unless they come with what ever is being replaced. Hold the thermostat itself in place with a dab of crazy glue or something like it and after applying the silicone barely tighten-on the housing. After curing overnight then get around to tightening the housing properly. Compresses the cured product. Always works for me.

[hodginsa]

And then let the gasket sealer cure overnight before driving it.

If it leaks after that, new engine. haha

[Movin]

upholstery adhesive...coat both surfaces and make sure alignment is correct when
both coated surfaces touch. They will bond into position. Use a silicone of your
choice to make the seal after position of component is secure. Bondable clean
surfaces are required.See above to obtain that surface.