Thermostat Housing Gasket Sealer

[76BroncoPete]

I picked up some permatex ultra gray to use when replacing leaking thermostat housing gasket. I may pull the intake manifold while I am at it and was hoping the ultra gray was suitable for both applications. I was going to get the high temp red for the thermostat housing but was hoping to kill two birds with one stone. Any corrections in my thought process or suggestions are welcome. Thanks

 

[gr8scott]

I prefer black myself, but you'll be okay with the grey. Let it cure at least overnight before firing her up.

 

[76BroncoPete]

Thanks for the response and info gr8

 

[Steve83]

Don't over-think this... The paper gasket is designed to do what needs to be done. And if the mating surfaces are still good, it probably will for many years. Look at this & the NEXT pics:

(phone app link)


I used a self-adhesive t'stat gasket, and CopperCoat on the intake & the hose nipples.

(phone app link)


Neither of those engines leaks now. They're not daily-drivers, but they DO get driven.

 

[DirtDonk]

And when you do use sealant, if you always check the specific temperature ranges of a sealant on their packaging you can compare to the situation you're going to put them in.
For example, if the Ultra Gray can function up to 400° (Just looked it up and it turns out it's up to 500°) then there is no problem. Your engine and coolant temps should never even reach the 250° range except for out at the exhaust ports/manifolds.

The combustion chambers get there of course, but the coolant, oil and overall engine bits never do.
So even with hot oil and hot coolant splashing up on the sealed surface, the stuff should be fine. You don't need some different kind of high-temp sealant.

Paul

 

[76BroncoPete]

I tend to overthink things and get stuck in place in that process. Thanks for the super motor links too Steve. Thanks for checking on that temperature range Paul and the extra Information too. I always appreciate the help guys. Thanks

 

[Rustytruck]

I use the permatex high temp red. the stuff takes a long time to go stale in the tube. so its there when you need it. its ugly but works. make sure the surfaces are clean enough to eat off of. then smear a thin coat on the gasket and its mating surfaces. let it tack off then put a bead on and stick the parts together. let it cure before adding any fluids or fluid pressure.

 

[76BroncoPete]

Got started tonight, bottom bolt behind the water pump was a good time. Thanks for the details rusty, the smear and bead technique sounds like a winner

 

[76BroncoPete]

Suggestions on getting these surfaces cleaned for the new gasket

 

[EricLar80]

Suggestions on getting these surfaces cleaned for the new gasket

Wire brush on an angle grinder. May need to file them flat if they are pitted.

 

[SevenT]

Thermostat housing and gasket

BroncoPete,

The wire wheel suggestion is how I did mine. Stuck a rag in the intake and hit the mounting surface and got it clean. Did the same for the water neck. I use Indian Head gasket shellac on things like this and no leaks. Another trick is to put the thermostat in the water neck and put a tie wrap through the end of it and connect it to an 8 penny nail on the hose side of the housing. This will keep the thermostat from sliding down in the housing and causing a leak. After install and gasket sealant cured, cut the tie wrap and pull it out.
Just my .02. Good luck.

v/r,

SevenT

 

[76BroncoPete]

Thanks for the help guys. I didn’t want to make a problem worse by heading down the wrong road. I will definitely use the tie and nail technique on the thermostat, great idea

 

[Rustytruck]

Got started tonight, bottom bolt behind the water pump was a good time. Thanks for the details rusty, the smear and bead technique sounds like a winner

if you put the thermostat in the water neck and glue the gasket on first it stays in place while you do the other side.
I know that lower bolt well I did one once that the bolt and thread was so corroded that the thread came out with the bolt. after struggling with that it meant the whole intake had to come out and spend the whole weekend fixing a 30 minute job and a 3 dollar gasket and turned into a hundred bucks with helicoil kit and all the associated gaskets and a can of marine antisieze. Old corroded aluminium intakes not assembled properly suck at times like this.
sometimes you beat on the Bronco and sometimes the bronco beats on you.

I learned over the years never start a Bronco project on Sunday you will not have the time to finish it