Thermostat Gaskets

WardL · #1 (**permalink**) 10-19-2010, 07:36 PM

I'm replacing my thermostat and the local auto parts store only had thin gaskets. The original gaskets were at least 5 times thicker. Will the thin ones work on my aluminum thermostat housing? Is there a recommendation on how much torque to put on the two bolts? Where could I find thicker gaskets? Sorry to ask such a trivial question, but what the heck!http://www.clubcobra.com/forums/images/smilies/erm.gif

bobcowan · #2 (**permalink**) 10-19-2010, 08:24 PM

I don't use a gasket. I use a good silicone sealant instead.

PANAVIA · #3 (**permalink**) 10-20-2010, 01:36 AM

I disagree, gaskets are mandatory. Your surfaces should be flat enough to only need the felpro standard. Set a straight edge across the surface as to determine if it is warped. Tourqe is 15-20 ft lbs max.

bobcowan · #4 (**permalink**) 10-20-2010, 08:52 AM

Quote:

Originally Posted by PANAVIA

I disagree, gaskets are mandatory.

Clearly not mandatory. On the Cobra, I'v been using Silicone only since the initial build. It has never failed. Althougnh I have changed the thermostat a couple of times in the last 5 years.

On my '66 Mustang, it held up for for about 15 years, until I sold the car. After the initial overhaul, I never removed the thermostat. The original silicone held up all those years.

CobraEd · #5 (**permalink**) 10-20-2010, 08:55 AM

Thinner/cheaper housings can warp under torque from the bolts and you will have a chronic leak. Make sure the surface is true and if not get a good THICK chrome aluminum housing from Mr Gasket for only about $15. I had a cheaper housing with a thinner flange and it always leaked due to warpage.

.

WardL · #6 (**permalink**) 10-20-2010, 09:47 PM

I haven't quite mastered pictures yet, but this is supposed to be a picture of the thermostat housing. It is also in my first photo gallery if it doesn't come up here. The flanges are pretty thick. Does anyone use the round "O" ring type gasket with this? You can see the groove in the face.

thudmaster · #7 (**permalink**) 10-20-2010, 10:42 PM

Ward, Roush has your gasket in stock. Thick ones or thin ones; I am not sure which is best but I find it intresting the factory uses them.......

bobcowan · #8 (**permalink**) 10-21-2010, 07:45 AM

Quote:

Originally Posted by WardL

I haven't quite mastered pictures yet, but this is supposed to be a picture of the thermostat housing. It is also in my first photo gallery if it doesn't come up here. The flanges are pretty thick. Does anyone use the round "O" ring type gasket with this? You can see the groove in the face.

This is what I use. I pitched the O ring a long time ago. Permatex red silicone only.

CobraEd · #9 (**permalink**) 10-21-2010, 08:01 AM

The Mr Gasket housing that I use has the exact same modified O ring. Never leaks.

.

Bernica · #10 (**permalink**) 10-21-2010, 08:35 AM

I just went through it a while ago. Used the peel-n-stick FelPro's from NAPA and a light coating of Motorcraft Ultra Silicone #TA-29. No issues, no worries.

rdc767 · #11 (**permalink**) 10-21-2010, 08:37 AM

Mine warped I couldn't seal no matter how thick the silcon or gasket was. I ran across it a belt sander. Sealed with just silcon now.
Ron

SuperHart · #12 (**permalink**) 10-21-2010, 09:42 AM

The trick I always use to check the housing flange is a piece of 400 grit wet/dry sandpaper on a pane of glass. Wet the paper and run the flange of the thermostat housing over the paper in a circular motion using even firm pressure. The high spots will show sanding marks while the low spots will remain chromed. Keep going until the entire surface is even. Silicone sealant on top of a gasket usually works well. Never had any issues using this method.

timsullivan · #13 (**permalink**) 10-23-2010, 08:12 PM

Ward: Who makes the thermostat housing in your picture?

-Tim

akfish · #14 (**permalink**) 02-02-2012, 11:50 AM

^^^ I'd also like to know, I think it's from roush, I've called roush 4 times in the last 3 days......no reply.

Caprimaniac · #15 (**permalink**) 02-02-2012, 03:19 PM

How hard i tried, the gasket would not seal- even if it's a OEM Ford thermostat housing, so silicone was the way to go. It seals.

Wonder if silicone on the intake side, then a gasket & bolting the housing on to let dry would make it possible to remove the housing later, for instance to test another thermostat, and then refit without changing gasket or apply fresh silicone would work?

jhv48 · #16 (**permalink**) 02-02-2012, 03:46 PM

I have the same engine and housing you do.

When I replaced the thermostat, I used a standard Felpro thermostat gasket with some silicone sealer to hold it in place during installation. No problems in 10,000 miles.

Rick Parker · #17 (**permalink**) 02-02-2012, 08:36 PM

What may be happening is the thermostat is sliding/falling out of the machined relief and the outer edge of the thermostat is being sandwiched between the manifold and Thermostat housing. No reason it should not seal.