UKPOC forums

Normally , no problem. You just keep 'unwinding' that Allen key socket until the piston drops out.
BUT , in your case it sounds as though there is no connection to the adjusting screw !

MikeyG wrote: ↑

Wed Jul 07, 2021 8:10 am

Is it easy enough to remove the piston? I've got one fully extended - I'm not sure if it'll help, but the guy isn't responding and I really want this done.

From what I remember, you unscrew it once the piston has been extended

And there's the problem - the circlip inside is missing. Cheeky git isn't replying to emails or eBay messages and it's been longer than 30 days so I can't open a dispute.

How do you get that circlip out? If I could take it out the old ones it might work.

Oh yeah, got it out in 5 mins with 2 straight picks!

Well done , that is the problem.
I think ebay will make an exception if you phone them.
The suppliers are also looking at serious problems for selling dangerous goods if they don't respond favorably.

Just to expand a bit on the place and purpose of that 'snap-ring/ circlip.
It MUST fit into a recess in the body of the caliper in such a place and position that it stops the adjusting screw from popping out when you stamp
on the brakes.
That adjusting screw has an O- Ring on it that completes the hydraulic seal.
Pray that the refurbishers have fitted an O-Ring of the right material or the brakes will fail one day.
I am a bit surprised you were able to get that circlip out with two prickers.
That doesn't seem right at all.
Keep us informed on progress , an interesting job.

Not just out but back in again too and it operates correctly now! I'll test it rigourously when it's all back together and, to be honest, I'll probably end up replacing it purely for peace of mind, but it's been a quirky little job to say the least.

Just removed the second caliper piston and they at least included a circlip with this one, even though it's not in the recessed bit.

Installed the 2nd circlip in about 10 minutes - suspiciously too easy. When winding the piston back in it made a pop and doesn't wind any more. I'll try putting in a known good circlip but thinking about just getting new ones as if they're this sloppy, what else have they scrimped on.

One on the left was fitted in the 'new' caliper. It's clearly too small and was popping out when turning to extend or retract the piston.

That would have been a brake failure just when you needed to stop quickly with your foot hard on the brakes.
Lethal.