sbf 260 leak at thermostat

okay i have tried to fix this three times now i need the experts. this last time i new put on new water neck housing and new sealer esp for water pump and thermostat. let dry 24 hrs. still have leak at bottom where it ****s to manifold. guys and gals i am at wit's end. what do i do for the fourth and final "fix". as usual thanx for your sage input! engine basically stock 260 in 64 ranchero. larry

 

Take a file and make sure the intake is flat and clean.
The houing do the same make sure the tremstat is under surface and dirt removed.The term must be in center trickie some times.
Make sure the theads are clean and not bottoming out. bolts may to long.

 

because they have a vertical surface they can be a *****. Aside from ****py replacement housings that can be warped, many times it's just the thermostat slipping slightly without you realizing it and that holds it off a hair - enough for a leak. You swear it's OK, but it's not. Been there
Also what George said about the bolts can happen too

 

x 3 on the bolts and the housings with the o-rings leak......a lot.

 

We learnt the hard way on my 302 if the water neck is chrome, file it down to the substrate and seal THAT. Chrome water necks are like ***s on a bull, if you ask me.

JK

 

First of all, the basics, make sure both surfaces are clean and straight. Then instead of using bolts, use studs, this way you can slide the housing on without disturbing the silicone which is probably why you're still having leaks. Also make sure you are using this stuff, and letting it cure for 24 hours if possible. This Permatex stuff never lets me down, it's great! Good luck.

 

to flatten a thermostat housing clamp a large piece of sandpaper to a flat surface and rub the housing back and forth.

 

....also, don't over tighten the bolts (or nuts if you go with studs).

 

I use permatex #2 on the gasket and bolts. could be the bolt holes extend into the water jacket and water is leaking thru the threads. shouldn't but.....

 

Do you have one of those chrome tiawon water necks? The one on my 390 warped at least 1/4 inch, yep, went right in the friggen' trash. Got me an old cast iron one and water tight now.

 

After 3 tries with the cheap chrome junk that had deep casting imperfections on the sealing surface that I thought I could fill with silicon I finally bit the bullet and popped for a stainless thermostat housing made in the USA.

Problem solved and it looks good, but not cheap.