School me on removing broken bolts.

[Jon in NC]

Let me start by saying that I am NOT a mechanic. But I own a '40 and I would like to work on it my self as much as possible. Well, last week I had a radiator hose bust which was an easy fix. But it was still over heating, so i thought I'd take out the t-stat. Looked pretty simple. Soaked the bolts in WD-40 for a couple of hours then put the wrench to it. Snapped both bolts about half way down the threads. Now how do I remove the rest of the bolts and what size are they for replacement?

 

[Jon in NC]

I guess no one has an answer or everyone thinks I'm an idiot. Either way, I sure would like some help.

 

[TLCA_Paul]

You need to get a set of stud extractors. There are different types. Some are long, and you use a tap wernce on them, others are stubby and you use a socket on them. I just got the set from Autozone. They came with the drill bits.

Use a center punch and get as sclose to the center of the broken bolt. Make a decent punch, then start drilling as straight as you can. Go deep enough to get a good bite with the exstractor, but not so deep you go thru, then thru the engine into a waterjacket or something bad.

Put the extractor in the hole, tap it in a few times, then carefully twist the bolt out.

But the problem is the bolt has been in there so long, getting hot and cold so much it has hardened. so drilling is not going to be easy. Then with rust, or oxidation on the bolt it will be stubborn to come out. try heat, try letting the heat cool. try lots of penetrating oil. I prefer PB blaster over WD40.

Then if you break the extractor you will have to try and drill that out too. If you end up drilling to big then you will need to put in a heli coil.