It is 12mm fine thread, the same as a 22R head bolt. Hard to tell but it looks like you may be able to start a tap in that hole. A 12x1.5mm tap calls for a 10.5mm hole. Your 3/8" hole is about 9.53mm. Close enough?

Cool, at least I have the tap already. Just need to get the bolt Thanks again guys I appreciate it.

>>>*K...Hope I am not too late. Now use a taper tap, same size as the threads since you need to save the threads.

Carefully feed it in until it binds, do not force it. Then back it out, clear all debris. Start again.

*Bit tedious but it works, be sure you stay aligned.

The so called EZ-outs work fine for bolts not frozen, but a simple screwdriver the right size will do the same thing and not spoil your weekend.

We do not allow hardened EZ-outs in the shop, they just break if the bolt is frozen.

Way too late to use the vibration trick, we take out rusted in place bolts with a simple peening hammer, (sometimes a mag tool) long story there, I will tell it if anyone has an interest..(My son and I have often taken out stuck bolts with our fingers, it always get a surprised expression from folks....)

Just use caution now, I can already see you have very good hands because you aren't off-center....*EB

man how many zip ties did you use on that caliper? haha. but the thread is m12x1.25. it is a really hard to find thread so you might have to go to a specialty store to get it. or you could just go to your local dealer. if you can get one from the junkyard that would be your best bet. just put some pb blaster on it before you take it off. i dont think its that common for those to break anyway so you should be good.

This is one of the lovely bolts on our trucks which is installed with loctite, so it's a bit of a hit and miss on breaking loose for doing maintenance.

Crawler, I like those extraction tools. Might have to get some to keep the reverse bits company. <img src="/forums/images/graemlins/kewl.gif" alt="" />

This is all good info and I'm glad you posted it with pics for all to see. The only thing that I can add is that one tool I always keep around is antiseize compound (the grey stuff). Anytime I do any work on my vehicles, I use a little antiseize to make future disassembly easier. Remember, many of us are dealing with bolts and nuts in the 15-20 year old range <img src="/forums/images/graemlins/zombie.gif" alt="" />.

when you drill metal, lube helps a TON! even a squirt of wd40 once you get the pilot started will make it cut a lot faster...

I'm always interested in your stories EB, so what's "the vibration trick"?

Well, first I'd like to thank everyone for their input. Roger and EB had some really good advice as usual. I started to go at it with the tap and since the one I had was not tapered I was going slowly. So after a few minutes with not much luck I started looking at it more closely. Turns out that I had nearly drilled out the entire bolt as you can see from the pics. There was a little pice of the bolt sticking out the backside that I was able to get a screwdriver on so I started whacking away. I managed to knock out what was left. The threads remained virtually intact. I ran the tap through it anyway and all is good. Here are a couple more pics. The first is the piece of bolt that was left and the second is the finished product before reassembly. BTW there were eight little zip ties holding the caliper up.

and

Now I can hit the beach tomorrow <img src="/forums/images/graemlins/kewl.gif" alt="" />