Share Your Tips & Tricks, for.... Cleaning Brake Pistons

[Wheelie_King]

Cleaning brake pistons to ensure even activation is part of regular maintenance, but not a job I’ve ever thought I’ve mastered.
The sticky pistons are always improved by my attempts, but never regain equal status with the smooth side pistons.
I tend to wedge a pair open while I work on the other pair - pump, clean, press in, repeat.
Is there a better way? Any specific lubes good to use or be avoided completely?

 

[baldiebenty]

I had to do this myself at the weekend as the front brake had basically decided to lock on and I found a good video with Calvin of Park Tools showing how to use a piece of string dipped in alcohol to "floss" around the piston to clean it. Wasn't able to try it myself as I couldn't find any string and had to resort to just wedging and pumping out one piston at a time and cleaning as best I could with an old toothbrush.

 

[Loe Rider]

+1 for Calvin's piston floss. Worked perfectly.. ?

 

[Mikerb]

If its a 4 pot calliper you have to block 3 to get one to come out sufficient for cleaning. I first of all thoroughly clean the inside of the calliper and faces of the pistons with IPA on a small paint brush. I then use a borrowed, never to be returned, make up brush ( think baby sized but quite stiff bristle brush) to clean each piston in turn. I use a brake block that blocks 3 pistons at a time. Then I wipe with a lint free cloth. Once all 4 are done I leave it for 20 mins to ensure all IPA traces have evaporated. Then repeat pushing each piston out in turn and lubrication with DOT 4 ( SRAM brakes). Then start again checking that each piston comes out clean..........sometimes one or more will drag more dirt out from its holder, so more cleaning required, but even if it does not the piston has to be worked in and out a few times to make sure the piston seal gets wetted by the DOT4 on the piston and lubricates it well. It all takes a bit of time but well worth it in terms of brake performance and I find it is only really necessary when I change brake pads.

 

[Cb750stu]

If its a 4 pot calliper you have to block 3 to get one to come out sufficient for cleaning. I first of all thoroughly clean the inside of the calliper and faces of the pistons with IPA on a small paint brush. I then use a borrowed, never to be returned, make up brush ( think baby sized but quite stiff bristle brush) to clean each piston in turn. I use a brake block that blocks 3 pistons at a time. Then I wipe with a lint free cloth. Once all 4 are done I leave it for 20 mins to ensure all IPA traces have evaporated. Then repeat pushing each piston out in turn and lubrication with DOT 4 ( SRAM brakes). Then start again checking that each piston comes out clean..........sometimes one or more will drag more dirt out from its holder, so more cleaning required, but even if it does not the piston has to be worked in and out a few times to make sure the piston seal gets wetted by the DOT4 on the piston and lubricates it well. It all takes a bit of time but well worth it in terms of brake performance and I find it is only really necessary when I change brake pads.

I pretty much do the same but use this silicone lube applied with a small brush on each piston , recommend by Hope ?

 

[galaga187]

I had to do this myself at the weekend as the front brake had basically decided to lock on and I found a good video with Calvin of Park Tools showing how to use a piece of string dipped in alcohol to "floss" around the piston to clean it. Wasn't able to try it myself as I couldn't find any string and had to resort to just wedging and pumping out one piston at a time and cleaning as best I could with an old toothbrush.

I followed that video and had an oh shi# moment when he said don’t pump too far - I already had and lost all the brake fluid.

 

[baldiebenty]

I may have had a whoopsie moment myself that resulted in having to do a bleed of the system

 

[Kernow]

Unbolt caliper clean with toothbrush and brake cleaner spray ,
pop in old worn brake pads to stop pistons coming out and pump the pistons out .
Pull out the old pads good scrub with toothbrush and brake cleaner , dry off with airline then silicone spray around pistons
re fit old pads to protect the pistons and push the pistons back . Proper piston lever tool helps .but wooden wedges are also good
Pump out and push back pistons until your happy they are not sticking . Wipe clean and reinstall / adjust with new pads .
Also a good time to change fluid and bleed when the pistons / pads are wedged back