TR2/3/3A TR3A Thermostat Housing Leak

[Skip_Shervington]

Replaced the thermostat and put the gasket in dry (is that correct?). I have a small drip there. Will that eventually seal it self as the gasket swells? I made sure the surfaces were clean and no burs before assembly. I'm pretty sure I have the nuts tightened as far as they should go.

Thanks!
Skip Shervington
Santa Cruz, CA
'58 TR3A TS34885L

 

[mrv8q]

FWIW, I always give my gaskets a very thin coating of Hylomar, both sides, and the housing itself a light pass of fine steel wool for any corrosion.....

 

[EV2239]

Loctite 5699 is the best. Hylomar is a World War II Rolls Royce gasket material and so not as good by an appreciable margin IMO.

Ash

 

[DougF]

I don't use a gasket. A coating of Permatex "Right Stuff", fasten it down and you're ready to go. No waiting for it to cure. Great stuff!

 

[CJD]

And...I've never been lucky enough to have a gasket swell and fix itself. Chances are it will keep leaking unless there is Stop Leak in the antifreeze. I am definitely NOT recommending you add any, though!

John

 

[luke44]

Well for those who come across this thread later, here's why it leaks, all the tightening in the world and hoping the gasket will swell isn't going to do it. Trust me, I am very tired of cleaning up antifreeze off the floor.

After 50 years of tightening/loosening and expanding/contracting, the mating surfaces get out of wack, stretching around the studs. The good news is these surfaces can be fixed easily by working back and forth on a flat bench having laid a piece of #100 sandpaper on the bench, followed by finishing off with a 200.

Even with that though, it still may leak. What's harder to fix is the new repro thermostats today are not 100% flat around the outside flange that sits in the recess. So, you have to remove 10-15 thou to get it to recess down. Don't let the gasket do more than it's designed for.

 

[titanic]

I had a similar problem with a TR6. A small leak around the thermostat housing. Replaced the gasket and it still leaked. Filed the face flat and it still leaked. Replace the thermostat housing and it stilled leaked. Finally, I noticed that the ID of the gasket was slightly too small and it rested on the thermostat. After enlarging the ID of the gasket, the leak finally disappeared.
Berry