How to: Change brake pads on a bicycle

First, the wheels are removed.

Next, you should check all connections and line transitions for oil leakage. Also look under the dust caps of the bleed nipple on the brake caliper and under the rubber boot at the transition from the line to the brake lever.

Finally, lift the protective caps to locate any possible oil leakage.

Now the wear condition of the disc is checked. This must be done with a vernier caliper – anything else is too inaccurate. First measure the thickness of the disc. It must not be at or below the wear limit, which is marked on the disc. Then you should also check the wear pattern. Is the friction ring (the effective braking surface) worn evenly and free of obvious damage? If so, the disc will be fine.

Finally, check whether the brake disc is properly tightened. For this you’ll need a torque wrench. Center Lock discs normally require 40 Nm, while 6-bolt discs usually need 6–7 Nm. In any case, check the exact torque specification given by the manufacturer on the brake disc itself or on the Center Lock ring.

The wear on the brake disc can be measured this easily.

To remove the old pads, the retaining clip must first be removed from the pad retaining screw.

Then the pad retaining screw is unscrewed.

Now you can squeeze the brake pads together and pull them out of the brake caliper.

Before you push the pistons back, their sliding surfaces need to be cleaned. Use an old toothbrush or some cotton swabs and brake cleaner. To loosen the brake dust, simply spray a bit of brake cleaner into the brake calliper. Then remove the brake dust with the toothbrush or cotton swabs.

You can then spray away the loosened dust again with brake cleaner and run a clean cloth through the brake calliper once more.

The pistons of the brake calliper can be pushed back with any tool that has a straight outer edge. Here we use a hex key – to be completely safe, use something made of wood or plastic, a softer material, as the pistons are not very resistant. The most important thing is that the piston is pushed straight back into its guide. Do not tilt it!
After pushing them back, the pistons must be flush or almost flush with the inner edge of the brake calliper.

Take a close look at the pads before installing them. Some brake pads are the same for left and right, while others are designed specifically for each side. In such cases, this is marked on the pad.

Important: Make sure your fingers are completely free of oil and grease, otherwise the new pads may end up in the bin straight away.

Before inserting the pads, you should “assemble” them together with the return spring.

The brake pads together with the spring are then inserted into the brake calliper.

Then the pad retaining screw is screwed back in…

…and the retaining pin is inserted.

After installing the new pads, pull the brake lever a few times, as the brake fluid first needs to “settle”. After several pulls, the pressure point should be noticeable again. Hold the brake lever firmly pulled for a few seconds. The pressure point must not move but stay in place. This ensures that the system is sealed.
You may need to realign the brake calliper so that the new pads are positioned optimally in relation to the brake rotor. If your brake runs without rubbing directly after the replacement, you can skip this step.