Broken allen wrench removal

I don't see where you have anything to lose by trying your favorite real penetrating oil, a couple of gentle heat cycles, a left-handed drill bit from the top (or remove the master cylinder and use a RH drill from the bottom) and try an easy-out.

Another trick I like is to make a little square of sheet metal about the size of a postage stamp, punch a hole in the center, and plug weld it to the end of the bolt (using O/A or MIG or however you can) then welding a nut to the sheet metal and using the nut to turn out the bolt. Might be tricky with the seals in the master cylinder so close, though.

Steel bolts frozen to aluminum can be very tough indeed. My guess is you'll wind up using a helicoil or equivalent, or maybe buying a new master cylinder.

My guess is this motorcycle isn't a BMW.

GWE

If it was the proper size Allen, it will come loose with a couple of taps back, the opposite direction from which it broke, if it was a SAE jammed into a Metric bolt, good luck. If it snapped and didn't twist, it going to be hard. Good Luck gary

As far as the wrench goes I can think of two things. First, use a punch to mark the center of the wrench. Banging on it may loosen it. After using the punch drill a hole that's the tap drill size for a thread size smaller than the wrench, but not by much. Tap the wrench stub. Even though the wrench stub is hard, a tap is harder. The tapping process will probably loosen the wrench stub if the drilling doesn't. Or, after drilling the hole, use an impact screwdriver with a phillips bit in the hole. Impact screwdrivers, the kind you hit with a hammer, can be had pretty cheap, like 10 bucks. If you already have the impact wrench, and it sounds from your post that you do, then you're set. Before using the impact wrench on the screw itself maybe a little oil and heat could be used first. I think drilling from the back side is way too much work. I bet that wrench stub pops out when you start to work on it. ERS

Yes. A Napolean bar end mirror. Throw the stock ones away.

Jim

And, since it's accessable, a few taps on the other end of the bolt with a hammer and pin punch to help loosen it???

Oops, I didn't notice it's the wrench and not the bolt that sheared. In that case, I suggest you drill a hole down the center of the top of the wrench, tap it, and run a long screw through it to bear on the bolt and push out the wrench stub. Or just freeze a welding rod to it and pull.

GWE

Wayne wrote:

If you are able to drill the Allen wrench, you might be able to get it out by packing the hole with grease, inserting a close fitting pin punch, and hitting it with a hammer.

John Martin