Disc brake caliper - advice/warning!

[mattsccm]

Now, there may be exclusions to this but on the whole, assumig mounts are the same, you can mix and match most Shimano calipers. It may well be cheaper to get something like a Deore caliper and swap it in.

[Miguel Evans]

thanks for all the tips. Tried the penetrating fluid, heating up etc. I think that they were chemically bound in. My local bike shop successfully drilled them both out for £50, so not a total disaster, but an expensive lesson. The chap left the callipers in situ, and drilled with increasing bit sizes until he could get the bolts out. Quite impressed, but he said that he has had a lot of practice!

[Jdsk]

Thanks for adding the solution.

Jonathan

[gregoryoftours]

Blimey that is some pretty impressive drilling skill to get them out cleanly!

[RJC]

Another similar thread:
https://yacf.co.uk/forum/index.php?topi ... msg2707777

[RobertMcC]

Hi
Just discovered this thread after encountering the same issue with my Shimane BR505 calipers. I had been loosening the screw occasionally over the winter months but when I went to change the pads I've went down the same hole as others have mentioned.

I've chewed the slotted heads so my next step is to try drilling it out. For those who have attempted this before what size of LH drill bit did you use and did you drill a pilot hole first?.

[531colin]

I had forgotten this thread......(and much else besides, but never mind!)
I have replaced the similar bolts on my (recent) Tektro disc calipers with stainless bolts.....must try to remember to give them a twist and report back!

[tim-b]

I've chewed the slotted heads so my next step is to try drilling it out. For those who have attempted this before what size of LH drill bit did you use and did you drill a pilot hole first?

Try for access rather than drilling. The thread is only at the head end of the screw so take the wheel out and cut the screw between the two pads so that you can a) slide the pads, spring and the circlip end of the screw out and b) leave a stub to grip that's more accessible than the screwhead

See if you can grip the screw inside the caliper and unscrew it from there. If that fails use a succession of smaller to bigger RH pilot drills and try to unscrew the stub at intervals because the heat might very well do the job as you go. For RH and LH drill size be guided by the hole in the brake pad

I use the screw type pad axle with a careful smear of copper grease on the thread and they've been fine for several years

[Brucey]

such seized bolts hold little fear for anyone in possession of a MIG welding machine. Putting a blob of weld on the screw head gives you something you can grind to shape and hang onto. As a bonus, the intense, localised heat usually frees up the bolt too. This works jolly well except on 12.9 or higher bolts, which tend to crack. Fortunately nearly all OEM bolts are 8.8 or 10.9 grade, both of which weld nicely.

[Cowsham]

Must go and check mine now cos I'll need to replace pads on my cube acid shortly.

[simonineaston]

Must go and check mine now cos I'll need to replace pads on my [insert brand x] shortly.

ditto…!

[Redvee]

I've chewed the slotted heads so my next step is to try drilling it out. For those who have attempted this before what size of LH drill bit did you use and did you drill a pilot hole first?.

I swapped mine for allen key bolts after reading similar horror stories.

[Cowsham]

Must go and check mine now cos I'll need to replace pads on my cube acid shortly.

Well the Cube is just a simple split pin but the pinnacle has the flat profile calipers with the slot head ( threads near the head end ) but also with a spring clip at the other end -- checked to see if any were seized but all perfect -- may put a taste of silicon grease round the threads or red rubber grease ( that's my choice for brake calipers on cars vans etc -- copper grease has a tendency to dry out and cause issues )

The electric bike ( subway 2 ) has Allen key bolts -- all OK.

[simonineaston]

I swapped mine for allen key bolts after reading similar horror stories.

I recall exactly the same situation, back when we owned motor bikes in the ‘70s. Many motors came fitted with fasteners unsuitable for repeated use. A common reaction was to replace the majority with Allen head bolts, sold as a set by enterprising entrepreneurs.
Thus we go like, plus ça change, plus c'est la même chose - or if we prefer English, what goes around, comes around.

[Brucey]

Must go and check mine now cos I'll need to replace pads on my cube acid shortly.

Well the Cube is just a simple split pin but the pinnacle has the flat profile calipers with the slot head ( threads near the head end ) but also with a spring clip at the other end -- checked to see if any were seized but all perfect -- may put a taste of silicon grease round the threads or red rubber grease ( that's my choice for brake calipers on cars vans etc -- copper grease has a tendency to dry out and cause issues )

The electric bike ( subway 2 ) has Allen key bolts -- all OK.

not all copper greases are created equal. What have you tried?