I've had a minor leak around the thermostat housing on my Roush 402 on & off for 2-3 years. There was a tiny leak this year which I decided to try to fix once and for all (I should have left it alone).
New gaskets. Leaked worse. New gaskets and gasket sealant. Looked like Bellagio fountains!
So I took my billet spacer (which was pitted a bit) and my chrome thermostat housing to a machine shop and they put them on a very flat table. The spacer was flat but the housing wobbled and definitely was the problem (I probably overtightened it in frustration). He said to just to just sand the spacer with a sanding block or on a flat surface to clean it up.
So I layed some sandpaper face up on my granite countertop and sanded the billet spacer and it cleaned up fairly good and it felt pretty smooth. I got some new felpro gaskets, new thermostat and a new aluminum t-housing from Napa.
I put it all back together, torqued the new stainless steel bolts to 15lbs. and of course it leaked. Without even starting the engine it dripped out pretty good between the housing and the spacer at the bottom.
Took it back apart and this time I added gasket sealant to the new gaskets and bolted the spacer and t housing together and let it sit for 1/2 hour to set. I then put a new gasket with sealant on both sides on the block side of the spacer and put everything back together. Leak was worse than ever, same spot.
HELP!!
