Sometimes you can take a small chisel, grind it down so it's even smaller, then use it to shatter the extractor.
The extractor is really hard steel so it shatters fairly easy.
When narrowing the chisel on a grinder, do it gently - don't let it overheat and turn blue, as that softens it.

If all else fails, there are places that can burn it out - they use a process similar to arc welding. Call welding shops, machine shops etc. - they'll know who does it. Some of those guys have it truck mounted and can come to you -- pricey.

 

Unfortunately I had a similar experience with the bolts in the cylinder head to hold the exhaust manifold on. We ended up pulling the head and taking it to a machine shop. The guy there seemed to think that he could get it out with a carbide tip drill bit. Still haven't gotten it back yet.

Chris

 

I've had some good results extracting brake offs by using a Dremel tool with a cut off bit. The trick is to make sure you can get the dremel tool at a right angle to the surface. Make a cut into the broken bolt/stud/screw such that it becomes like a screw. You'll also cut a bit of the surrounding material on both sides of the bolt so make sure this wont interfere with sealing... After using something like liquid wrench, use a screwdriver that tightly fits the cut you made, and does not reach into the surrounding material, and remove it like a screw. A diamond wheel cut off bit will likely cut through the hardened extractor aswell as the stud...

http://www.dremel.com/productdisplay/bit_template.asp?SKU=545&Color=CC0000

 

I don't know if this will work for your situation, as it may be too heat sensative. I have had good luck getting all sorts of snapped-off bolts out by welding through the appropriate sized washer to what is left of the bolt-stud. Then, weld through the middle of a nut to the top of that, and maybe tack it in a few places on the side. Most times, you can put a wrench to the nut and turn it right out. My father and I do this all the time to head studs and the like on a variety of old tractors with much success. I'm not sure if the manifold can take the heat without damage. Is it iron or Al? If iron, I'd give it a try. Of course, if you don't have a welder...

 

Thanks for all the ideas. I could definitely have tried the weld trick, but the stud is now flush with the top of the intake manifold.

I may try to cut a slot on the top of the bolt extractor, then I should be able to pretty easily turn it clock-wise with a screwdriver to back it out...once that's out of the way, I can easily drill and re-tap the hole.

This forum is a great place!

Bob

 

Tyrone has the best way I have found to get the stud out. Even if it is flush. I have gotten broken bolts out that are 1/4 or more reccesed by doing this. You want to get a good weld on the stud and melt it out on the washer,then weld on the nut. The heat shrinks the stud and breaks the rust loose. Be sure and let it cool before you try to remove it. Let it cool on its own. Also it might take more than one try. Good luck

 

Look for a tool place in town the sells metal/machinist working tools. There is a tool that's used to drill out around the broken stud and the extractor. We don't sell them in our store, but if you want I can look in some catalogs tomorrow to dig up a part number.

 

I've never had one I couldn't get out with one of the above methods. One note- the better the quality of the extractor, the easier it is to shatter. That's usually my first attempt. If it's too soft (read cheap), I try the cutting wheel. If neither one of these work, a lot of new expensive drill bits will eventually chew down through it. At some point, it usually gives up and just falls out of the hole

. What type of extractor was it- square, twist-flute, straight flute...?

Steve.

 

He He -- Never thought of welding through a washer - shields it from the surrounding metal! Great idea!

Recently I found a set of reverse drills at -- would you believe -- Autozone!

Sometimes heating and cooling it with a propane torch, then using the reverse drill backs it right out.

 

I had the same problem, but I fixed it with a cutting torch. The drill bits and bolt extractors melt at a different temp than the manifold, or maybe it's because you are putting the heat on a small piece of metal [the broken bit] vs the manifold [bigger mass absorbs more heat]
Anyway, cover yourself up and try to aim straight down. Sparks will fly EVERYWHERE!
I was able to save the threads in the manifold the last time I did this, but I had planned on using a helicoil.
I had though of taking it to a machine shop, but figured the cost might be near the price of another manifold.
Good Luck

Bob

 

There are also special welding rods made specifically for the job. Supposedly you don't have to worry about the rod metal sticking to anything it doesn't touch. I personally prefer plain ol' 7018 or 7014. The nut trick can work really well, and sounds like it might do you some good. Like Rich, I've done it a million times and never thought to use a washer.

Steve.

 

Thanks again everyone for your input.

Looks like we've all encountered broken studs at one time or another. I've always been able to get them out with a bolt extractor or by grinding the sides of the remaining stud square, then using vice grips or a wrench. I never would have thought of the welding trick! Great info.

BTW, the stud extractor that I used & broke was the twist-fluke design.

Thanks.