thermostat housing gasket

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Roadart

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When installing a t/h gasket,what do you use? My original (when I got car) had pinhole leak. I cut new gasket,used red rtv(lightly) it also leaked. Bought gasket,again red rtv ,leak again. Should I try gasket and no rtv? RTV,no gasket? It is on a 318 edelbrock performer manifold.
 
Roadart said:
When installing a t/h gasket,what do you use? My original (when I got car) had pinhole leak. I cut new gasket,used red rtv(lightly) it also leaked. Bought gasket,again red rtv ,leak again. Should I try gasket and no rtv? RTV,no gasket? It is on a 318 edelbrock performer manifold.
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Last one I did with permatex water pump gasket sealer. If you are using an original thermostat housing I believe the gasket goes on first, then the thermostat, then housing last. Some of the older one just get pourous and are hard to seal. After market ones can have issues like not enough nipple to hold the hose under pressure .
 
My method was a bit different..... first I tried the gasket that came in the new thermostat box. After I wiped up the huge mess that the massive housing leak made, I tried a home made gasket, and RTV. Next came a second round of clean up for the slightly smaller leak and mess. I added a sprinkling of curse words on this round.

next step was make a gasket out of thicker cork gasket material and a healthy smear of RTV. I added a lot more swearing when this resulted in a leak similar to step 2

Next I tried lapping the aluminum housing base on a piece of glass and emery cloth, chucked the thing up into my lathe and recut the shoulder that the t-stat sits in. One more time with the cork gasket and a thin layer of RTV.

No more swearing and a little happy dance when it stayed dry under pressure.....finally.
 
i noticed the last time i got some generic thermostat gaskets from autozone that they are crap, to put it nicely. what ever they're coated with will not seal properly. no sealer / RTV / tack spray / gasgacinch = POS gaskets. get some felpros, i got a 10 pack. use nothing or a very thin layer of whatever your favorite gasket sealer is, and be happy
 
Roadart said:
where did you get the o-ring housing?
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I'd have to look at my receipts. It's been 7 years or so. I think I bought on on Amazon. And I went with a Coolflex hose.
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I had the very same problem. Broke down and bought a billet thermostat housing with the O-ring and have never had a leak issue since.
 
I had a helluva time getting the T housing to seal on the 318 in my truck, after several tries with different gaskets, sealants, housings, etc, I tried a silicone gasket. Done deal, and it's reusable, been on and off a couple times so far. $10 or so apiece, so I bought a couple more for stock. That said, the Billet Specialties o-ring unit on my other motor sealed from day one.

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Im having the same issue. I used a ??? Gasket that had adhesive on one side. Used gasket adhesive i have been using for years. Dang thing seeps when cold holds pressure when hot. Im going to try the following next.
rtv, gasket, rtv, BUT put rtv on and let it setup for an hour or more. Than assemble. I recall reading someware that when ysing rtv you need to let it setup a bit before assembly. Then sfter the setup time tighten. Im sure we have all seen gaskets squeeze out with rtv on them. I do like the silicone gasket. Might try that. Notice the inch pounds and dry placement
 
MOPAROFFICIAL said:
I smear a film of rtv on each side with my finger.
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I make my gaskets sometimes too. I finger spread black rtv silicone on both sides and let it almost set up before installing. If ur surfaces aren`t pulled out of shape from overtightening (mine were) it should work for u too.
 
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