Removing stubborn screw on disc pads.

ted1

I’ve a dodgy screw on my from brake that’s preventing me from changing discs.

Seems to have been over torqued. It just does t move and now the head is more or less gone. Ive tried a few different oils

Any tips. ? Can the Caliper be opened ? So I could get the middle section with a vice grips and try to turn it that way.

magicbastarder

you mean the threads are stripped too?
do you have a spanner to try with that instead of a screwdriver?

ted1

magicbastarder wrote: »

you mean the threads are stripped too?
do you have a spanner to try with that instead of a screwdriver?

No threads aren’t stripped. They screw just isn’t budging ! It’s a round head. A spanner would be no use.

cajonlardo

I am guessing you have tried releasing oil?
I have dealt with this in the worst case
The head of my retaining bolt just crumbled

I used hacksaw down between the pads to cut through the bolt
Removed the pads and tried a vice grip on what was left. In my case that broke and I ended up using a drill to remove remainder

If you damage the thread on the caliper don't panic - you can use a good quality split pin

Sounds a lot worse than reality

ted1

No joy. As per your experience the screw broke in the vice. I tried drilling but I only had a masonry but so didn’t get to far.

I’ll have to order a new one and I suppose a bleed kit too.

I’ve sent Cube a mail asking that it be replaced under warranty as it was over torqued or not greased.

cajonlardo

I wouldn't go buying a new one.
Just get a few metal bits.
Drill with smallest bit first (no bigger than 1mm) and use the old bolt hole on the empty side of caliper as a guide.
The remaining bolt is very soft metal and easy to drill.
Once you've drilled into it use the next bigger bit and finally a bit large enough to completely remove the remaining part of the bolt.

While I'd personally drill it without too much worry ,
Someone with no experience is going to absolutely butcher the thread.
Even when the bolt is drilled out you'll need to run a tap through to clean it out.
Unless you can afford to write off the part bring it so someone.
I'd try and slot the head first and try it with a really big flat driver.

ted1

BrownFinger wrote: »

While I'd personally drill it without too much worry ,
Someone with no experience is going to absolutely butcher the thread.
Even when the bolt is drilled out you'll need to run a tap through to clean it out.
Unless you can afford to write off the part bring it so someone.
I'd try and slot the head first and try it with a really big flat driver.

My understanding is that you don’t need as few and shimano vary between screws and pins.
No harm butchering it, as I’d needed to replace it if I didn’t try.

Like in this kit. So no thread needed
https://www.chainreactioncycles.com/mobile/ie/en/shimano-b01s-acera-altus-disc-brake-pads/rp-prod178950?gs=1&sku=sku686454&istCompanyId=0f15660a-f13e-4c09-a701-b55d8c3f2e59&istFeedId=21ccdaa5-24f7-4b32-9ec6-ac7081b9b50b&istItemId=iwxrlrtii&istBid=t&pgrid=55940684381&ptaid=pla-416421672662&utm_source=google&utm_term=&utm_campaign=PLA+All+Products&utm_medium=base&utm_content=mkwid|sUB1RUEEU_dm|pcrid|294740729969|pkw||pmt||prd|686454IE&gclid=CjwKCAiAg9rxBRADEiwAxKDTupufmUp6zmdpEz-c2T2nOF9e4wUro7JEZVXPFh0Rcback50_rvSAcBoCYAIQAvD_BwE

magicbastarder

ted1 wrote: »

I tried drilling but I only had a masonry but

urgh; that's like using a hammer when you need a chisel.

Looking at this reminds me of a horror of a botch job I did last year in a similar situation in which I should have asked here first and then was too embarrassed to to post about. LBS had a good chuckle and took near €150 off me.

Expensive lesson

cajonlardo

BrownFinger wrote: »

While I'd personally drill it without too much worry ,
Someone with no experience is going to absolutely butcher the thread.
Even when the bolt is drilled out you'll need to run a tap through to clean it out.
Unless you can afford to write off the part bring it so someone.
I'd try and slot the head first and try it with a really big flat driver.

It won't matter about the thread (although be great if it worked out properly)
He can use a split pin instead of a bolt, plenty of manufacturers do this already.

As he looks at the caliper now, he can see the broken bolt in one side and the "hole" on the other side of caliper is now empty. This hole is not threaded

If he uses the empty hole as a guide and starts with a 1mm metal bit, go in a couple of mm, then a 2mm bit and so on until he is through.
Trick is to keep backing off, don't wait til bit jams in the bolt.

If you really want to save the threads, go in with 1mm bit for about 3mm. Now put the 2mm into a vice grip and go nice and easy. Every few turns back out and change back and forth between the bits until you come through head of bolt.

Its really not a big job at all but you do need a variable speed drill running slow and you do need decent bits and the more patience the better the result.

BTW, I ran a split pin for years without issue on front on a road bike

rubadub

cajonlardo wrote: »

If he uses the empty hole as a guide and starts with a 1mm metal bit, go in a couple of mm, then a 2mm bit and so on until he is through.

I would forget about the threads, as you say they are not needed.

Most drills I have used would not take a 1mm drill bit as the chuck can not go that small. Dremels might. Also 1mm drill bits are extremely easy to break.

In future a tip with stuck bolts is to actually tighten them a little and then try undoing them, works a lot of the time for me.

Slotting the broken head was mentioned which I have done, but can be tricky to do.

ted1

Ok update time. I got proper drill bits and used a 1, then 2 then 3. And it worked the head of the screw is still in it but I fitted a pin through it.

Not pretty but it works. The caliper is a bit cut as I only had a full hacksaw as opposed to a mini.

But wars wounds add to the life of a bike.

Thanks all for the tips