Well,
After killing 2 6mm allen sockets (sheared 'em off!), I finally managed to blow out the internal hex of the block's coolant plug on the left side of my M119. Unfortunately the plugs hex died when it was approximately 1/2 way out. It is not leaking at 15psi. and has shown no signs of leaking when run, but I'd like to get the darn thing out and put in a new one (w/ some antiseize!). I am considering using a combination of heat and an extractor, but I am concerned about breaking off the extractor's tip. Anyone have any suggestions out there? Fortunately the right one was easy to remove! Thanks in advance for the suggestions.

Andy

Just had this same problem with the 6mm hex nuts on my alternator mount. Take a socket that bareley fits over the 6mm bolt, (cant remember if I used 10 or 12mm.) Use a socket that has multiple small teeth inside of the socket instead of the ones that have a six sided cutout. Put an extension on the socket and then hammmer the socket onto the head of the 6mm bolt. Pound it on good. Once its on tight, use your ratched to unscrew the hex nut. Work like a charm.

Do a search, removing stubborn screw fixingsis a bit of a regular. I would not use an extractor, if it breaks you're in real trouble. Try a torx bit that's just a bit too big and hammer in in. This will cut some new shoulders on the recess, and you can have a go at unscrewing the plug.

Any screw in device will leave you with a hole and hence a leak.

Is there enough of the plug exposed to get some mole grips (vise grips?) clamped on? This should give you more leverage.

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Cheers, Neil