Removing a broken bolt

[BrewMaster]

Does anyone have any suggestions or tricks to remove a broken bolt? I overtightened one of the Torx bolts holding on my front brake rotor and snapped the head off. The shaft of the broken bolt is still in my hub and I can't figure out how to remove it. The shaft is down deep in the hub, so I can't cut a groove in it with a Dremel or anything.

Thanks.

[foofighter]

get a really good quality drill bit and slowly drill it out using gradually larger drill bits?

[BrewMaster]

Would it come out of the threads that way? Or would I end up having a bolt with a hole in it stuck in my hub?

[Sprockethead]

Take it to the pros. I stripped a bolt for the brake rotor and La Habra Cyclery drilled it out for me.

[foofighter]

i've seen it done where you get to the point where you can physically pick at the shell and it falls out of the threading. after that depending on how good you were w/ the drill you may have to re-tap the thread to clean it

[Pato]

You could drill a small hole through the bolt then use an EZ out to unscrew the bolt. Carefull and steady hands are key here.

[project_d]

Originally Posted by Pato

You could drill a small hole through the bolt then use an EZ out to unscrew the bolt. Carefull and steady hands are key here.

I agree w/Pato. An EZ-out is the best way. All you do is drill the appropriate hole diameter, tap (or bang) in the EZ-out, and as you turn it, the screw/bolt should come out with it.

I stripped the hex part of a pedal once, and somebody recommended the EZ-out to get it out. Works like a charm!

[kanga]

EZ Outs are the way to go.... but on that size bolt it will be difficult to do. Gotta be accurate with the drill. You have to drill a perfectly on-center hole into the bolt shaft that is no more than half the diameter of the bolt itself, then use a left-hand threaded easy-out to screw into that hole, bite, and pull the broken bolt shaft out.

[CalEpic]

That bolt will be a bitch to get out given how small it is. Your most likely going to have to drill it out and helicoil it.

Or you could prob run the rotor with 5 bolts and be good.

[foofighter]

you've got nothing to loose give it a go! i bet you can do it...do you have a drill press? that way it'll be totally perpendicular to the surface

[project_d]

Originally Posted by CalEpic

Or you could prob run the rotor with 5 bolts and be good.

That is not out of the question. I know Eric Carter runs his rotors using 3 bolts for weight saving purposes. He said he's never had a problem running 3 bolts vs 6 bolts.

[northshore]

I use a wheel saw to cut a slot on the top of the broken bolt and then a large flat head to unscrew it. If it's really stubborn, I'll use a flat head socket attachment on a break bar.

[2wheel_lee]

Depending on the Loc-tite used, you may be able to simply tap on the bolt with a drift pin and a hammer (to relieve the pressure on the threads), then try to back it out. Use the drift pin as a center punch for the next step.

A good EZ Out kit often comes with left-hand drill bits. I've had a lot of success simply using the left-hand bit to drill the hole, and the bolt just comes out with the bit.

[RustyIron]

You want to drill the bolt out exactly on center. It will be difficult because the bold will not have broken off perfectly square and your drill will wander.

First drill it small and try an ez-out. If that doesn't work, drill the hole bigger and try to coax out the remainder of the bolt with a pick.

My mill will accommodate a 26" wheel, if you want to bring it over. It will allow more control over where the hole goes. There are, however, no guarantees. I might fix it, or I might hand you back a ruined chunk of metal with a sincere apology.

[BrewMaster]

Thanks for all of the suggestions folks. Right now I am running it with 5 bolts but I would prefer to have it balanced. Probably not a big deal, though.

When I get home I will see what I can do. I don't want to drill it free hand because I am not that good and RustyIron is correct, the bolt surface broke unevenly. With no drill press at my place, I may take you up on the offer to have you try it on your mill Rob.

There's an outside chance that I might be able to coax out the end of the bolt from the back side of the hub. The spokes will make this hard, but I am going to try it since I have nothing to lose.

[DeeZee]

Originally Posted by BrewMaster

Thanks for all of the suggestions folks. Right now I am running it with 5 bolts but I would prefer to have it balanced. Probably not a big deal, though.

When I get home I will see what I can do. I don't want to drill it free hand because I am not that good and RustyIron is correct, the bolt surface broke unevenly. With no drill press at my place, I may take you up on the offer to have you try it on your mill Rob.

There's an outside chance that I might be able to coax out the end of the bolt from the back side of the hub. The spokes will make this hard, but I am going to try it since I have nothing to lose.

With the bolt surhace being uneven this is what I would do

1. Put some Liquid Wrench (or something simmilar) in to the hole. Let it sit over night
2. Get the smallest drill bit possible and carfully drill a hole
3. Then increase the drill size until it matches the correct size for the ez out.
4. EZ out that puppy

[OTHRIDER]

Rob,
Another "trick" we use on bolts that shear off at angles - take a small diameter center cutting endmill and create a small flat. I have some very small center drills (.050" and up) if needed. After that a sharp drill shouldn't walk off center.

Sam,
If things get messed up, I do have a zillion heli-coil sets at the shop in both American and metric. I'd be happy to teach you how to use 'em.

(In my best Clint Eastwood twang) Sam runs with 5 bolts and wears his diapers low....

[ghixon]

As others have said - drill and an E-Z Out.

Here's a website to help explain the process. Good Luck!

http://www.asashop.org/autoinc/may2003/techtotech.htm

[BrewMaster]

It's nice having some skilled machinists on here. With it raining this weekend, I am sure I will have time to get this sorted out. Again, I really appreciate all of the feedback.

Whenever I break something I end up learning something new. This time should be no different.

[RustyIron]

Originally Posted by BrewMaster

Whenever I break something I end up learning something new. This time should be no different.

That's the spirit!

Recently when I was planning some work on a priceless and irreplaceable part, a more experienced friend asked if I wanted to bring it over for him to do.

As I had the tools for the job, I politely declined.

It seemed asking him to do my work would be equivalent to an inexperienced groom asking his best man to come over and do the "work" on his wedding night, because he wanted to make sure everything worked out satisfactorily.