This guide is for you if your brake calipers look something like this:





Notice the dead brake pads and the somewhat less than clean pistons. No wonder why the brakes are feeling crappy!

Work on one caliper at a time, leaving the other one bolted on. First,
find a piece of metal/wood to fit down the central groove of the
caliper once the pads (or their remains) are removed. With this in
place pump the brake lever until all the pistons come out and press up
against your bar like so:

At this point, use your favourite cleaning agent to give the whole
lot a good scrubbing - paying particular attention to cleaning the
areas of piston that were exposed before. I like to use the "Wizzo
Wheels" stuff to clean brakes, not its intended use but it works very
well.


Note: Make sure the stuff you use isn't corrosive, or you could damage the pistons.

Now that the caliper is relatively clean you can start on the
pistons. Use a small pot of brake fluid to dip cotton wool buds into
and then use the buds to clean the pistons and around the seals.

Next take the cap off the master cylinder and very slowly
push each piston back into the caliper. If you push too quickly, the
fluid won't have time to drain back up into the master cylinder and
you'll cause one of the other pistons to push out instead. So remember,
do it slowly.

Once the pistons are pushed back into the caliper the level of
fluid in the master cylinder will have risen, and depending on when it
was last changed it might look rather grotty:

You can take this opportunity to suck some out using a syringe and replace it with fresh fluid.

Once again insert your length of bar into the caliper and pump the
lever to bring out the pistons. They should move more easily this time.
Depending on how long you have you can repeat the cotton wool bud &
brake fluid routine a couple of times, I usually do it twice for each
caliper. Once you're happy with the condition of the pistons it's time
to move on.

If you're going to replace brake pads give the backs of them a
slight smearing with copper grease before inserting them. This stops
the pistons sticking to them.

At this point if you want to go the whole hog you can replace your
standard rubber hoses with braided steel ones to give the brakes a
firmer feel. See Stew's excellent guide for details on how to do this.

Finally try this trick: Leaving the cap off the master cylinder pull the brake lever in and secure it in place.

Leave the bike to stand overnight then in the morning give the
calipers and brake lines a good tapping/twising, starting from the
bottom and working your way up to the master cylinder. Once you're done
release the lever and replace the master cylinder cover.


Note: Cover
the top of the master cylinder with a piece of paper or something
similar to prevent the brake fluid absorbing moisture from the air.

Voila! Better brakes

All thanks for this guide goes to:
User: Korn, from bikechatforums.com