Exhaust manifold broken bolts

[Rawze]

(07-18-2021 )Lead_sled Wrote:  So, I’ve found while searching that this seems to be a common occurrence.

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cummins had an old TSB for this issue.. it is a common problem with older manifolds that are not drilled out quite far enough for proper heat expansion. here is the thread that talks about this and I posted the the proper reemer to use...
http://rawze.com/forums/showthread.php?t...9#pid39699

Also the #1 or #6 likes to snap exhaust bolts if the expansion joint gets severely rusted up and cannot slip in and out under heat loads. That is another common issue.

WHATEVER YOU DO >>>!!!! The best way to prevent exhaust bolts from snapping ... NEVER EVER EVER EVER EVER EVER INSTALL THEM WITHOUT A TORQUE WRENCH!!... Always torque them exactly to spec so that they can expand according to specifications.

Personally, I also use a very light coating of anti-sieze on the bolt threads and shanks too, although the procedure does not recommend/call for it. I have always had good luck with them this way, and have not seen one break by doing this. I also use a very light coat of anti-sieze on the gaskets (both sides) too, to help them seal better. When I say "light coating", I mean "very light" coatings... like wiped a tiny bit on, coating everything, .. then off again with your fingers, no excess at all.