Thermostat housing seal

[James Case]

I am having the hardest time trying to get my thermostat housing to seal on my 7.3 turbo since I replaced the thermostat. I have taken it on and off easily 5 times trying every sealing process I can. What have y’all had luck with finally getting it to seal as far as techniques for installation or sealant that y’all have found to be the best. Someone told me yesterday to try “the right stuff”. I’m desperate at this point. Truck has been down for too long. It doesn’t make sense to me why they would discontinue a part like that. I’m willing to bet a new housing would seal right up. Thanks guys

 

[Reggie f250]

Is the housing clean and flat? If not try putting sandpaper on a flat table and run the housing over it. Clean off with brake cleaner. Make sure the engine side is clean. Reseal with sealer. Right stuff is very good, ultra copper is good too. Hope that helps.

 

[James Case]

I have done all of it man. Literally text book. I’m at my whits end

 

[James Case]

Do y’all recommend putting a sealant on both sides of the gasket or just one side against the housing and none against the block? I have tried it both ways with no luck.

 

[Benm2002]

What brand T-stat did you use?

When I did mine the new T-stat had a rubber seal around the outer lip that my original did not, it just comes off but if left on there is no way it would have sealed.

If you’re not already get a Felpro gasket, the grey fiber gaskets suck. You can also try putting Hi-tack on both side but only if both surfaces are flat.

 

[Randy Bush]

Need to make sure to only use a Motorcraft or OEM style one. All I use and have never had a problem with things sealing up , and the large rubber seal around the themostat needs to be there.

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[Benm2002]

Mine was Oem style (couldn’t find a motor craft one locally).

That’s not the rubber seal I’m referring too.

Mine looked more like this one (not exact) but it had a rubber seal on the edge.

You must be registered for see images attach

 

[James Case]

Wait, so you are supposed to leave that gasket around the outer edge? I have always been told to remove it. I do have a motorcade stat.

 

[Benm2002]

It won’t seal unless you remove it. I believe Randy is talking about the bigger rubber seal on the base, which should stay.

 

[James Case]

OK yeah I have never even thought about taking that one off. Most of the good ones won’t even come with that ring around the outside

 

[aggiediesel01]

Is it possible your housing has a crack in it?

 

[Thewespaul]

Get a motorcraft one any other will fail. Amazon typically has it next day

 

[Cubey]

Get a motorcraft one any other will fail. Amazon typically has it next day

Walmart has them too by ~2 day. That's where I got mine.

 

[James Case]

I have motorcraft thermostat in it. It’s all I’ve ever run. I have inspected the housing well and cleaning the hell out of the flange. It always leaks at the lower bolt.

 

[James Case]

Do y’all think I could have a blown head gasket and it’s over pressuring the cooling system and that’s the weak point? I have had to replace radiator a couple times.