Thermostat Leak - Need Advice Please!

[zzmac]

Everything is brand new except for the billet spacer. The leak is coming from between the new housing and the spacer. The spacer doesn’t appear to have any cracks in it.

[Gaz64]

Flat surfaces on housings, completely clean and dry, 1.5mm bead of RTV on both sides of each gasket, let set 10 minutes, assemble, torque bolts to 10lbft, LEAVE OVERNIGHT, refill with water first, water is cheap, all ok, drain out, and refill coolant, bleed system etc.

[Ron61]

I have had some trouble with spacers not being completely flat. Clean everything off very well, wipe it dry with alcohol or some non greasy cleaning agent and then put it on a completely flat surface and see if you can see any deviation at all in the area where the leak is. I used a wire brush to clean mine and there was a very tiny, almost impossible to see place that wasn't flat. But I made up for this as mine had an O ring groove so I used a slightly oversize O ring and gaskets which I put some sealer on and let set for a minute or so then put everything back on and torqued it down. I never had so much as a drip after that.

Ron

[patrickt]

Originally Posted by zzmac

Everything is brand new except for the billet spacer. The leak is coming from between the new housing and the spacer. The spacer doesn’t appear to have any cracks in it.

I know, but that doesn't mean it's any good. If everything is clean, plumb, flat, and not cracked then you can usually just use a homemade gasket, and tighten it down with a wrench and you're good to go. Try doing what Gaz wrote and, if that fails, then something is either warped or cracked, even if you think it isn't. That's the only possible answer.

[Andheeezonit]

When I want a leak free assembly, I use Indian Head gasket cement, done!