I have been trying to replace my front brakes for a while now. I stripped out one bolt on the front wheel and I snapped the head off another when I first tried to remove the front rotor.

Since then I have broken three drill bits and three ez-outs.  I have tried using a dremel to cut a slot in the top of the stripped bolt and using an impact screwdriver to get the bolt out. That just shredded the bolt, so I cut the head off of the bolt, removed the rotor and tried using ez-outs again. My drill bits survived, but I did snap off another ez-out.

I've pretty much given up on getting the bolts out myself.  Right now, I am planning on taking the wheel to a machine shop to see what they would charge me to remove the bolts. Otherwise I am going to be buying a new front wheel.

Does anyone have a suggestion on where else I could take the wheel? Does anyone have an idea what a machine shop might charge for something like this?

is there anything left of the bolt to grab? or is it pretty much flush with the wheel now?

was the rotor completely worn out or something? usually, the rotors don't need to be messed with unless it's under spec.

Not sure how much a machine shop would charge to drill/tap but it can't be too much.

edit: meant to mention, if you have anything left to grab, try using either a stud remover or directional channel-locks.

There is a little bit left to grab of the bolt circled in red (the fuzzy part is metal shvings from drilling out the I have tried using vise-grips and I have had no luck. They just slide around. I don't think that I would be able to put enough torque on it using channel locks, and I know that a pipe wrench wouldn't fit in that space.

The one circled in blue is recessed about .25" below the surface. There is no way to grab it with anything.

I decided to replace the rotors becuase the surface is really grooved, they are getting close the minimum thickness and I need to replace my pads.

I have a wheel sitting with a snapped extractor in it as well. I thought about taking it to a shop but wheels are fairly cheap, probably cheaper than what the shop will charge.

Looks like fun.  Me and my dad, well my dad mostly got a broken rotor bolt out of my Bandit wheel.  He drilled it out and then tapped the whole out.  On the one circled in blue that might be possible to do since you have exposed threads at the top to guide that tap but the other one might be tricky.  You need to have some real sharp hi quality tools when attempting to do that, thats the number one thing.

You might try placing the old rotor back in place as a jig to aid in drilling the holes for the bad bolts. I've been lucky in such situations and was able to get the holes drilled straight...even without a drill-press. Just start with a small bit and drill a pilot for the larger bit. Another thing to try if you haven't already is to apply heat to the affected area around the bolt you can still grab and see if that decrease the break-away torque. Then you would only have one hole left. Oh but Goat you know you love that little GS and you love this forum too.

C.......

Quote from: dgyverI have a wheel sitting with a snapped extractor in it as well. I thought about taking it to a shop but wheels are fairly cheap, probably cheaper than what the shop will charge.

I thought about that, but I have a brand new tire on this wheel. I would rather avoid having to pay to have the thing remounted. Cost aside, are there any concerns with having a tire taken off a rim and remounted are there?

Quote from: sprint_9Looks like fun. Me and my dad, well my dad mostly got a broken rotor bolt out of my Bandit wheel. He drilled it out and then tapped the whole out.

Did you end up re-tapping the hole, then? Did you make the new hole larger? If so, how did you get new bolts for the rotor? These bolts aren't normal and I would be worried about replacing them with anything but stock parts.

Quote from: cerunosI've been lucky in such situations and was able to get the holes drilled straight

At the rate this project has been going, I'm not doing this myself unless I can get access to a drill press, some good drill bits and taps. I'm frustrated enough as it is and I just don't trust my ability to drill a straight hole.

Quote from: cerunosOh but Goat you know you love that little GS and you love this forum too.

Yes, I love her but I wish she wouldn't spend as much time being broken. I swear that I have spent far more time fixing my bike than I have riding it. Oh well, hopefully that period will be over soon.

Quote from: goatDid you end up re-tapping the hole, then? Did you make the new hole larger? If so, how did you get new bolts for the rotor? These bolts aren't normal and I would be worried about replacing them with anything but stock parts.

We drilled right down the center of the bolt with a drill bit just small enough that it would just touch the edge of the threads.  After it was drilled out we used the threads as a guide and ran it down just as if you were cleaning paint or something out of the threads.  In the end the threads were a little messed up but it held 20 ft. pounds yesterday when we put the rotor on.

Drill out the bolts like cernunos said.  Start with a smaller drill bit and work up to a bigger bit.  Use some Liquid Wrench because after you drill a hole in the middle of the bolt you might be able to use an ez-out or extractor bit(better than ez-outs IMHO.)  Did you say that you had an ez-out broken off inside a bolt...use any carbide tipped bit.  I've even used carbide-tipped router bits...worked like a charm.  If all else fails, drill out the entire bolt and use a Heli-coil kit.  It is like an oversized coil that you insert into the hole and it returns it to the original thread size.  www.helicoils.com

I'm with DOM, the heli-coil will probably even be stronger than the original thread too. Goat, don't worry about messing it up, you'll be surprised how well it goes if you just pay attention and go slow and steady. Keep lovin' it...the Baby and this forum.

C.......

Quote from: cerunosyou'll be surprised how well it goes if you just pay attention and go slow and steady

Thats the problem though. I'm too impatient. Maybe I should try to fix that... :lol:

Thanks so much for your help everyone. Now I have a bunch more general questions, some of which I have been wondering about for a while.

What are good drill bits? this is what I have right now. Are these bits good enough to be drilling through screw extractors? If not, what drill bits would be good for that? I would rather not pay snapon prices but I'm not buying any more harbor freight drill bits, either.

I know that the broken off screw extractor is in a hole which is off center. In the past, every time I have tried to re-drill a hole to make it centerized, even using a drill press, it hasn't worked. What do I need to do to make sure that the hole is going to be in the same place that it was before? My first thought is to cut off as much of the top of the bolt as I can without damaging the surface of the wheel and then use the rotor as a guide like cerunos suggested. I just don't know if the rotor is thick enough to be enough of a guide to keep the bit straight enough. The only thing that I can think of to fix that is to make a boss and weld it onto the rotor. I just don't know if I really need to do something that drastic.

Along the lines of getting a hole in the center, is there a better way to make sure that the hole is centerized other than getting some centerpunches (I think thats the name for them. They are cylenders of metal with a really sharp tip. They usually come in a set and are ment to be the same diameter as the hole you are trying to drill) or using drill bits in the same manner?

For bolt sizes, ronayers lists the rotor bolt as an 8x33. I know that the first part means that the bolt is an M8, and has a standard thread pitch becuase its metric. What does the 33 mean? 33mm of thread would be my first thought, but I want to be sure.

When clearing out the threads, is there a certain type of tap that is better than others? Are there any types of taps to stay away from?

Thank you again for your help, everyone.

Good brands of drill bits include Union Butterfield and National Twist Drill.  Any machine shop supply will have them or a similar brand.

Getting through the screw extractor will be fun.  For something around 7mm I'd use about 800-1000 RPM on the spindle.  Keep the chips spiraling and use coolant.  Motor oil works well in the field.  If you apply too little pressure the bit will wander, too much pressure and it will be forced from the extractor into the softer wheel.  Don't use a smaller drill bit than necessary either.  Small bits tend to bend and drill around the extractor.

The best way to get a center in the field is to use a centerpunch that will fit snugly into the hole.  Haul off and whack it to make a nice deep impression.  Pilot the hole and then drill it out to as close to the minor diameter of the thread as you dare go.  If you're lucky what remains will spiral out without damaging the thread.  If not, a Heli Coil shouldn't hurt anything.  

The center on the fastener circled in red will be more difficult.  There's bound to be a little play in the rotor due to the clearance fit for the bolts.  You might try using a couple of drift pins instead of the bolts to line up the rotor.  Then centerpunch as before.  

Use a plug tap to clean the threads and then run a bottoming tap to reach all the way to the bottom of the hole.  Finding metric at a local machine shop could be an issue.  Victor Machinery in NY has them in stock.  Stay away from the cheap crap.  Buy a good quality tap, chances are good you'll need it again.  

Quote from: goatI thought about that, but I have a brand new tire on this wheel. I would rather avoid having to pay to have the thing remounted. Cost aside, are there any concerns with having a tire taken off a rim and remounted are there?

No problems. This is done all the time.

One concern I have with using a heli-coil in the wheel is that there is not much material left once it is drilled out.