snapped bolt

Old 11-25-06, 06:54 PM
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snapped bolt

1988 Dodge Dakota 3.9L.Thermostat housing was leaking.I snapped one of the bolts off.There is plenty of room to drill it out but can't find a bit that will drill it.What kind of bit should I use?
Old 11-25-06, 07:27 PM
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You can get high carbon bits at auto parts stores or at tool supply stores. I believe instead of trying to drill out all the bolt material, which would make a mess of the threads, I would get an 1/8 inch or 3/16 to get a clean hole in the center of the bolt and try using a stud extractor to take out the broken piece.

Before you drill it take a center punch and rap the end of the bolt a few times. That should loosen the bolt in the threads. Then drill the extractor hole and see if it won't come out for you.

When you put the bolts back in put a little antiseize on the threads - just in case you have to do it again in a few years.

Hope this helps,

Old 11-26-06, 03:32 AM
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+ 1 what marbobj said.

When you drill, make sure you drill all the way thru the broken piece and not halfway thru, and use lots of rust penetrate, start out with a small drill bit if too tight, try the next size bigger, you DO NOT wanna break the extractor/easyout in it. Take your time.
Old 11-26-06, 01:16 PM
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all good tips, you might also try using a left hand drill bit, sometimes you get lucky and the broken bolt will break loose while you're drilling it.
Old 11-26-06, 05:28 PM
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I have removed many bolts using "easy-outs". be patient drilling so as to get a straight hole and USE CAUTION, some bolts are in a blind hole, if you drill completely through the bolt you will drill into or through the casting. Not nice. Also titanium bits are readily avaiable use one. Another thing, I have had better luck with the fluted "easy-out", seems the spiral ones want to "spread" the hole, as well as tighten inside it. Regards Lenny

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