Disc Brake Reminder - Exercise/Clean your pistons

[bikerboy337]

Learned this lesson recently. My disc brakes became soft, lost modulation and just were plain lousy, so I set about bleeding and getting things all set, pads are fine, bleed was fine, just still lousy braking.

Realized the calipers were sticky, so followed the online guidance, cleaned, exercised them, lubed a bit with brake fluid, exercised again (screwed up and over extended one caliper and had to re-bleed).

End result, wow, properly functioning disc brakes are way better than gunked up pistons that don’t extend evenly! Who would have guessed.

Anyways just a note to anyone else that does their own maintenance, part of my normal maintenance will now include cleaning the pistons/caliper, exercising the pistons and lubing them up. 2 of my bikes are now like new thanks to doing this l, took a whole 15 minutes for each bike….

[dolface]

Good reminder!
Two tricks I learned (from a Park Tool video iirc) are to use a chunk of rotor as spacer to keep from over-extending and pistons, and use cotton string soaked in alcohol to clean the sides of the pistons. wrap the string around the exposed piston and floss it back and forth.

[Carbonita]

Nice upgrade from my qtips. I also use Simpson strong tie rebar hole brush (big orange carries around here) to scrub the caliper.

Originally Posted by dolface

Good reminder!
and use cotton string soaked in alcohol to clean the sides of the pistons. wrap the string around the exposed piston and floss it back and forth.

[benb]

What kind of brakes were they? Shimano?

I’ve just been flushing my brakes with alcohol for almost 20 years now, never had a sticky piston but I’ve also never had Shimano discs and this seems to be a Shimano thing.

[tellyho]

Mechanical discs ftw

[bikerboy337]

Mine were sram, a set of force and red… neither have seen rough conditions but I’ve never maintained the pistons… realize a little maintenance here and there is the way to go on these now….

[dolface]

Originally Posted by bikerboy337

Mine were sram, a set of force and red… neither have seen rough conditions but I’ve never maintained the pistons… realize a little maintenance here and there is the way to go on these now….

Hope and Hayes for me and it's just something I do whenever I do a bleed. Hope also has free 3d files to make a couple of tools to help w/ cleaning/rebuilding calipers which is pretty neat: https://www.hopetech.com/open-source-tools/

[merlinmurph]

Q: How do sticky calipers cause the problems you had?

When my calipers were sticky, they just didn't retract well and would drag.

Glad you got things working well again. Confidence in your brakes is a must.