Exhaust manifold leak

[bushwood]

"Question about an exhaust man

"Question about an exhaust manifold leak. Chrysler 440s, fresh water
cooled. Exhaust manifolds were off last winter and gone through.
There is an anitfreeze leak on the port engine, inboard side, rear two
bolts on the exhaust manifold. I can see antifreeze seeping out from
the bolt heads (they are tight) when coldand hot. When started, seeping is
still prevalent. I pointed this out to my mechanic who did the work
and he said he was not surprised; that they were prone to this. He
extracted the two bolts and his method was to apply silicone sealer on
the threads and torque back down. Seems reasonable, except I am still
seeing seeping antifreeze from the bolts. Some have suggested swapping out bolts, reapply a hi temp sealer liberally on threads...Any suggestions?"

 

[captain_ed]

I would pull the manifold and

I would pull the manifold and check to see if the mating surface is perfectly flat. A flat file can smooth out minor imperfections. I have succesfully used "JB weld" to smooth out minor pitting on the mating surface on cylinder heads. Mix it up and use it like joint compound on dry wall. Sand it smooth with a block and fine black sandpaper.

It is worth a try.