I can't seem to get a good seal around the thermostat housing basically it leaks. I tried it twice and no dice. First the gasket was sealed with silicon and I got a slight leak. Second try was with gasket sealer I got a heavy leak. Each time it's in a different place. I even used the wrench with 18 Ft-lbs. Third time I would like to get it right so I need suggestions. How do you guys get a good seal? Do you use gasket sealer?
Make sure that both surfaces are clean, as well as the bolt threads. Lay a straight edge over the surface of the thermostat housing to make sure it isn't warped. I then put the stat in the housings recess for it and use trim cement to
hold the gasket in place. This keeps everything where it belongs while you put it in place and bolt fast. I don't use any gasket sealer on that area simply because I don't want to spend 10 minutes on clean up thex time it comes apart.
As Kotzy said, "Make sure that both surfaces are clean, as well as the bolt threads. Lay a straight edge over the surface of the thermostat housing to make sure it isn't warped." If the housing is slightly warped as has scratches you can use a metal file to even out the surface, if no file is available you can place a piece of 150/220 grit sandpaper on a flat surface and slide the housing back and forth until the warpage or imperfections are mostly gone. As far as gasket sealer goes, I like to use Permatex No.2. Use a piece of cardboard or paper plate and apply a moderate coat to one side and even out the layer with your finger, flip gasket over and apply a coat to the other side in same manner. I lift the gasket off the cardboard surface and inspect the first side for any gaps in coverage, if so use the sealant still on your finger to fill any gaps in coverage. I then squeeze some sealant on my index finger and thumb and I coat the entire threads of the housing bolts. Allow sealant about 10 minutes to get tacky, insert thermostat into recess, apply gasket, put housing in place, insert bolts finger tight, and torque to specs. It works for me, good luck.
Thanks! Permatex No.2. did the trick. I just followed the directions on the back of the tube. I cleaned the treads but I didn't use the sealer on them and I forgot to use a straight edge over the surface of the thermostat housing too. I any case I waited four hours before I tested the seal. This time I got no leak... thanks for all the good advice.
If your housing and block surfaces are uneven, you can STILL get a leakproof seal the way I did .....
I glued the gasket on the housing, letting it dry overnight. Then instead of using bolts, I used studs with the same thread pattern. I applied gasket sealer to both the housing/gasket side and the block side. The studs helped it line up perfectly without slipping around and getting the gasket crooked like when you are trying to put bolts in. I cinched down the nuts and the thing never leaked again.
Try using three (3) thermostat gaskets instead of just one. The extra gasket material will more than make up for corrosion or slight warping.
The only sealer I use on gaskets is "Gaskga-cinch" by Eldebrock. It is just a light rubber cement that holds your gaskets in place as you bolt things up. Your gaskets will come off easily if you have to remove them later. Gaskets are designed to seal without any help. Some sealers will actually cause leaks.
Last edited by BulletProof300; 07-01-2007 at 08:18 PM.