Brake pivot bolt

al_kidder

I've got a sticky front brake, shimano 105 that I'm trying to pull apart to give a good clean.
The pivot bolt is (so far) impossible to separate. Shimano's parts diagram shows it in pieces, but maybe it gets locked together on assembly.
Should it come apart or not? If it should, any tips beyond soaking it in WD-40

masjer

Which generation of 105 is it? Are you talking about the mounting pivot bolt? If so, there's a small grub screw (hex) that holds the bolt. The bolt that holds the arms together has a locknut and is also threaded into the arm itself.

al_kidder

Mounting pivot.
Not sure about series, but I'm hoping, if I can't free its movement, to swap the bolt into an unused rear brake that I have and put that on the front

al_kidder

By mounting, I mean the bolt that goes through the fork

masjer

The mounting bolt on the rear caliper will be shorter than the front, so won't be long enough to go through the fork.
If you find the grub screw, it should come apart and clean up enough to use again. Have you tried to see if it's reverse threaded? ie clockwise to undo.

al_kidder

So you're saying that I can't just swap the two bolts? The parts diagram says that bolt length is the only difference between front and rear

masjer

Having reread, I think I slightly misunderstood. So you are going to use the rear caliper on the front once you've swapped the pivot bolt. It probably is possible once you've disassembled both, but I've never tried.

photonic69

What series? This is a 5600 series caliper but similar to later models. You can see the grub screw but it is un-numbered. (between 6 & 8)

https://si.shimano.com/api/publish/storage/pdf/en/ev/BR-5600/EV-BR-5600-2442B.pdf

darkhairedlord

If you do put a rear caliper on the front, do remember to turn the brake blocks around or the pads could come out!

masjer

^ Very good point.