Technical Thermostat housing sealant, what works?

"The Ultra Grey I used just didn't seem to work."

There is magic afoot.

 

It's supposed to cure in 24 hours. It had 30 before I filled it with coolant.

 

Sounds like you've done everything correctly which suggests to me that there is another cause. Pinhole in either the hose (possibly under the clamp) or a pinhole in either your intake or your housing.

If the thermostat is seated, the intake and housing are flat, you are using the correct gasket and a smattering of sealant and you haven't forgotten to install and tighten the bolts , I'd be taking a close look at all the involved components.

 

Just keep on smearing goop on it , you may find some goop that works , different goop works sometimes & sometimes it doesn't , or it might work for a while , then quit , some actually diagnose problems by disassembly & inspection , consider that .
BTW , quite the attitude from someone looking for help .

 

I was looking at Fel-Pro's recommendations. I think the RTV was a bad choice in this application. I just hope it holds on my timing cover. I'll try it again a different way and see if I can get it to be better.

Yeah I can see where the leak was, it was sliding past the gasket, I think it was just the RTV was slippery so doing the opposite of what it should have.

 

Thank you for your valuable input. I disassembled and inspected it. What I used didn't work. That's why I'm asking what has worked for others.

 

This should be a tech thread on how to insure you never get help again if you ask.

 

The only thing that makes sense to me is the housing is bending when it is being tightened. "perfectly flat, gasket, and sealer" should not be leaking.

 

You aren't using Banjo Bolts are you?

 

Leaking thermostat housing thread...will it go three pages?


Too good.

 

If this is the type you're using ,you might try a replacement .

 

i've always used #2 permatex.

i remember my first thermostat replacement. i had done a few oil changes, i was just 16 and was warned about overtightening the bolts on the pot metal housing. i was real careful, snugging the bolts up equally using a 3/8 ratchet, and then only using my finger tips on the ratchet so as not to put too much behind it. i straightened up from leaning over the radiator, proud of myself for changing my first thermostat and started to walk away and heard the snap.
oh no you didn't i remember thinking. yep, housing cracked a good ten seconds after removing the wrench from it. son of a******, that could only happen to me.

 

I asked an easy question in three different forums and I got 95% off-topic replies. "What sealer have you used successfully for a thermostat housing with a gasket?" Not a hard question. So yeah, I'm annoyed. Thanks for your input.

 

RTV is slippery until cured, I'm learning. Even though it had 30 hours, I don't think it cured. It seemed to work on my manifold, but not in a thin layer on the water neck.

 

I have used it and it works great but it can be hard to get things back apart.

 

How old was the RTV? It does have a shelf life.

 

Bought it a month ago and just opened it Saturday.

 

I was at a bar with several buddies years ago. We were standing, watching the band. We had a pitcher or two of beer with us. Whenever a hottie walked past, we would all (or at least I****umed "all") would turn and watch her stroll by. Turns out, each time we turned to the left, one of my buddies on my right would top up my glass without me knowing. I lift the glass, look at it funny, shrug and continue drinking. Finally, he was laughing so hard while doing it, he spilled some on my hand and I caught on.

Point being ... are you sure a bud, your wife, cat, dog, trunk monkey, garage rat ain't spritzing a bit of coolant for a laugh ?

 

Well.......I can answer the original question: use 3 Bond sealer. Used to be called Yamabond, or even Hondabond.

 

I think you've been watching too many Wile E. Coyote cartoons.

Yes, the geyser that I had when I worked the throttle under the hood while it was running that was spraying on the fender and windshield was coming from exactly where I saw it coming from. The imprint on the gasket that shows the leak path that was exactly where the coolant was from also matches.

I'm in Canada, so it's antifreeze and not water. Not only does that make it easier to track, but it's also more expensive.

 

I've heard of Yamabond but didn't know there was another name for it. Thanks!

 

Hmm that's a good point.

 

That might work! Thanks!

 

Solved my aftermarket thermostat housing leak by installing a O ring ring version.
No sealer.

 

Not available for my engine unfortunately.

 

I use this stuff called FIPG on anything that needs to be sealed to prevent water leaks. It’s never leaked anywhere I’ve used it.

 

I've never used that. I'll look into it, thanks!

 

I would get all surfaces spotless, wipe with lacquer thinner, make a gasket out of heavier paper gasket material and use permatex 2

and lose the attitude, not much gets a thread closed faster than drama.

 

Going to stick my scrawny neck out and be prepared for the HAMB ax. I've used the coppercoat stuff from Permatex on several hard to seal things, even header flanges (its good to like 800 or so) and it did the job. I used it on a chrome/O ring Tstat housing and never had a problem.
Where's the ax?