Replace your brake pads
1 Don’t use the force
With the caliper on the bike, undo brake pad retaining pins and fasteners holding anti-rattle plates (where applicable). These often seize thanks to heat, dirt and moisture, so decent tools and a careful approach are essential. An impact driver may be required for stubborn bolts. Don’t force anything – get it wrong and the caliper is scrap. With everything loose, you can then remove the caliper.
2 Now it’s time to come clean
Now remove the brake pad retaining pins, clips and anti-rattle/ squeal plates – thin slivers of metal or wire fitted to the pad backing, bolted to the caliper or wedged in under the pad. Clean them up with brake cleaner and a light abrasive on heavy deposits and corrosion. Replace any missing or damaged fittings, especially any with chewed heads, which may not come out at all next time you try to remove them.
3 What are the pads trying to tell you?
Inspect the old pads. They should wear more or less evenly – slightly thinner at the rear edge is normal, but a large difference between pads or leading/trailing edges signifies a problem with the caliper or discs. Clean the caliper and pistons up – your normal bike wash or soapy water and a toothbrush should be fine for regular dirt. Thick dirt or corrosion warrants a full caliper strip.
4 Prep your pistons
On twin-disc front ends, loosely refit the old pads to one caliper and wedge something solid between them. Gently pump the lever to push pistons out on the other caliper until 10-15mm is protruding. Clean the piston that’s showing, apply a thin smear of red rubber grease or silicone lubricant to the pistons, and push them home. Repeat the process on the other caliper.
5 Avoid disc damage
If you are changing brand or type of brake pads, you must clean the disc of ‘transfer film’. Brake pads function in part by depositing a film or material on the disc surface, so old material must be removed before using a new pad. Use a Scotchbrite pad and brake cleaner to clean the swept area. Wipe the disc with a clean cloth to remove residue and debris.
6 Fit pads and plates
If you have anti-squeal plates fitted to the pads, ensure they are clean. Some like putting copper grease on the back of brake pads to reduce squeal, but a correctly-assembled and cared-for brake should not require this and it can attract dirt. Refit pad-retaining pins – if they screw in to the caliper, use copper grease sparingly on the thread, removing excess. Fit any security pins.
7 Refit caliper
Clean the caliper bolts and threads. Refit the caliper. Ensure one pad fits either side of the disc, and thread the retaining bolts in with your fingers. Don’t use grease or threadlocks – they affect torque wrench settings. Use a torque wrench to tighten fully. If you have removed any hose retainers or clips, refit them and ensure hoses are correctly routed with no twists or kinks.
8 Get pumped up
Repeatedly squeeze the lever until you have firm pressure. If you can raise the wheel off the floor, spin it and feel/listen for brake dragging. New pads often drag a little more, but it should spin at least half a turn with a firm hand if all is well. Opposing pads should have similar clearance from the disc. Excess or uneven pad contact warrants further investigation.
9 Scrubbing in
A little patience will ensure longer, stronger and more consistent performance. Go for a ride, allowing extra space to traffic. Moderate – not light or heavy – brake use, with reasonable regularity is a good way to transfer material. If you have to brake heavily, move away shortly afterwards to allow the brakes to cool. The brakes will come up to full strength in 50-100 miles.