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help! stripped allen screw

This topic contains 14 replies, has 8 voices, and was last updated by  sew 1 yr, 1 mo.

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Erica

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May 31 2013 at 5:35pm #

My brake pads were put on so tightly that I stripped the screw while attempting to remove them. I tried a brand new allen key, a pair of pliers, and a pair of vice grips. My brake pad is now crooked, unable to move, and my bike is functionally unrideable.


Drewbacca

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May 31 2013 at 6:50pm #

If you can’t get any leverage on it, then you will have to drill it off. You want to use a drill bit that is the same diameter as the bolt-shaft… you drill down through the head of the bolt and when the drill gets to where the head connects to the shaft, it should snap off and allow you to either pull the bolt-shaft through the other end or expose the shaft enough to get a pair of vice grips on it.

At this point, it isn’t a job for an unpracticed hand. You have to be precise with the drill and if you still need to unscrew something after that, you are going to want to use a penetrating fluid like liquid-wrench.

Can you loosen the brake cable the way that you would remove the wheel? If you can get leverage on the pad itself you could try twisting that with a pair of pliers. You’ll need a new pad afterwords, but you should be able to twist it from the other side. Use some liquidwrench first.


Jacob McCrea

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May 31 2013 at 7:10pm #

^Good advice above. You could also remove the wheel and see if you can put the vise grip on the brake pad, and unscrew it that way (i.e., using the vise grip). If you are in a bind and need a drill and drill bit, give a call at 412-six five one four six three four. My shop is near the South Side Slopes. We have tools and are happy to help.


Erica

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Jun 1 2013 at 5:24pm #

after taking an ill-fitting bike with a tube that wouldn’t hold air today, I got desperate and took a hacksaw to it.

chipped some of the paint on my fork, but at least I get to ride “the good bike” tomorrow.


jonawebb

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Jun 1 2013 at 6:02pm #

A hacksaw shows perseverance.
The only way I learned how to fix anything on my bike was by doing it the wrong way first, sometimes more than once.


Pierce

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Jun 2 2013 at 11:26pm #

Gah; I think I’m going to see if I can replace all the hex screws on my bike with Robertson screws; lubricating screws helps with that problem too though, but I’m not sure if that should be done on brake pads; perhaps a blue thread lock would serve the same purpose in preventing the screws from corroding

Gah, finding metric, stainless square drives doesn’t seem so easy


Drewbacca

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Jun 2 2013 at 11:36pm #

heh… I’ve stripped Robertson screws before. O.o Best to just remember to use grease or threadlock in order to prevent chemical bonding between metals.


jonawebb

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Jun 3 2013 at 7:11am #

To prevent stripping, the best screw is the flat blade — leverage gives you the maximum possible torque. And you should use an anti-seize grease, which contains sacrificial metal, to prevent bonding.


gg

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Jun 3 2013 at 8:28am #

BP Blaster.


gg

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Jun 3 2013 at 8:29am #

gg wrote:PB Blaster.


gg

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Jun 3 2013 at 8:29am #

PB Blaster.


Drewbacca

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Jun 3 2013 at 10:32am #

jonawebb wrote:And you should use an anti-seize grease, which contains sacrificial metal, to prevent bonding.

I think regular old grease is fine (I use marine grease for the extra water resistance)… you just want to create a barrier from oxygen and prevent metal-to-metal contact. Anti-sieze is great stuff, but I can’t think of any reason to pay the extra $$$ to use it on a bicycle. I think of it as more of a high temp/ high pressure system solution. Certainly it’s OK to use… but it seems like overkill to me.


jonawebb

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Jun 3 2013 at 10:42am #

Well, if you ever have a screw seize up in your frame and have to drill it out and retap or use a helicoil, you’ll wish you’d used it. And a can lasts for years. Piece of mind.


Marko82

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Jun 3 2013 at 11:49am #

If the screw head is just stripped (as opposed to the screw being seized), another approach is to take a file and flatten the sides of the head. Then you can use an adjustable wrench to turn the screw out. Best pic I could find with a quick search


sew

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Jun 3 2013 at 1:40pm #

If the screw head is just mangled like Marko82 shows above, they also make a tool that I believe is called an easy out. It looks bit like a drill bit. The bit has sharp edges that will catch on the mangled screw as you use the drill in reverse. Once it catches, the screw backs out fairly easily. They even work if the head of the bolt is off but you might need to drill a hole first. I bought mine at Sears, three sizes to a pack. $10, I think. I’m less nervous about snapping a bolt now.

PB Blaster is an awesome helper as well.

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