[Alpine Scrumper]

Changed the pads on my disc brakes today (105 hydro). The rear caliper was v straightforward, bolt unclipped, unscrewed, old pads out, new pads in – job done. Went to do the front and the screwdriver has striped the head off the bolt which seems to have seized with dirt.

Can order a new bolt online easily enough but any suggestions on how to get the old one out? Needle Nose pliers would be my first thoughts….

Topic

[brokenorange]

Why Shimano make these bolts

Why Shimano make these bolts out of aluminium is beyond me! the same thing happens with the bleed screws in the shifter hoods.

[brokenorange]

Had the same thing a few

Had the same thing a few months ago. I tried everything… cutting new slot and flattening the bolt edges didnt really work as the access is hampered due to the design of the caliper. I then cut through the pin axle with a dremel tool. This got the pads out and the non thredded section of the bolt but i still couldnt shift the thredded bit. I then drilled thought the centre of the bolt to hammer in a hex bit, still no luck.

In the end I drilled though the whole lot destroying the thread on the caliper. I reassembled the brake and am now using a split pin instead of the axle. This was recomended by my lbs, they even recomended removing the other one and replacing with a split pin. It has worked absolutely seamlessly since. Dont be afraid of “the nuclear” option if nothing else works.

[Alpine Scrumper]

So the pliers arrived and
So the pliers arrived and seem to be a nice quality pair. But they’ve had no effect except to make it worse. The bolt metal is so soft it just deforms with any approach. Think I may have to drill it out…

[Canyon48]

I’ve had good results by

I’ve had good results by gently tapping in a torx head (slightly oversize of the hole) and getting it out that way.

Be REALLY careful, you can easily wreck the threads if you “tap” it in to hard. Also be even more careful on carbon, you can cause delamination in the carbon by whacking it with a hammer.

[hawkinspeter]

Was that one of those slot

Was that one of those slot-head pins? When I got one of those seized, I took it to a bike shop and they used a dremel to cut a new head into the pin and then remove it.

When you get it out, replace it with a hex-head pin instead – they’re much better.

[CXR94Di2]

If the head is too difficult
If the head is too difficult to work with(caliper damage risk). cut pads out and use a pair of mole grips on the shaft .
You should have enough metal to grip onto

[Anonymous]

my first go to for stripped

my first go to for stripped bolts or screws (if theyre proud) is to use a metal file to make two parallel flat sides then use pliers to turn

[Alpine Scrumper]

Thanks for the tips folks – I

Thanks for the tips folks – I like the look of those pliers so I may give them a go. I’m reluctant to drill the bolt out but have seen drill bits you can get that remove bolts so those’ll be plan B and then bike shop as last resort (assuming it’s open). 

[cqexbesd]

I’m not sure of your exact

I’m not sure of your exact setup but if you can’t get them out by pliers (pliers like neijisaurus are designed for this job in particular) then you have some other options.

If you can get to the end of the bolt (either end) you can use a rotary tool (e.g. Dremel) to cut a slot in it and then use a screwdriver in the slot to turn it. If the bolt is seized then some pentrating fluid before hand would be a good idea.

If that isn’t possible you can drill the bolt out. You need to start with a very small bit and gradually increse size till you have hollowed the bolt out. Then pliers will alow you to break the bolt up and pull it out. It’s importnat you keep your bit inside the bolt at all times or you can damage the thread of what the bolt is in (or worse). A steady hand, sharp bits (and you will need multiple to get through a regular hardened bolt (or a way to sharpen them)) and cutting oil will be needed.

 

A further technique will be to disolve the bolt. The bolt will need to be steel (but not corrosion resistant). Whatever it is stuck in needs to not be steel. I have only ever done it with an aluminium frame. Use a stong solution of potassium aluminium sulfate, heat gently, stir occasionally and leave the part in it. The steel will disolve and leave behind everything else, including the threads, perfectly preserved.

 

[Hirsute]

How proud is the bolt? When I
How proud is the bolt? When I have neglected to check the cleats on my mtb shoes, I have used a dremel tool to score a new slot in the bolt, then I could use a screwdriver.

Or possibly a screw extractor https://www.amazon.co.uk/Damaged-Remover-Extractor-Hardness-62-63hrc/dp/B01E9ZC2K2

[ibr17xvii]

Same happened to me & I had

Same happened to me & I had to get the bike shop to get it out. The screws are a nightmare.

Replace with one of these (when you get the screw out):

https://www.wiggle.co.uk/shimano-br-m785-pad-axle-snap-ring/

[Author]

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