Disc brake pads are a consumable component of your bike, and it goes without saying that it’s important to keep them in good condition.
Low power braking, a high-pitched howl when braking in the dry (it’s normal for them to make noise in the wet) or excessive lever travel can all be symptoms of worn out or contaminated disc brake pads.
Thankfully, renewing them is a five-minute job and they’re cheap and light enough that you can – and should – always carry a spare set when out riding because it’s not unheard of to wear through a set on a particularly long and muddy ride.
This guide applies to disc brakes on both road and mountain bikes and, though the guide specifically shows a Shimano brake, the process is almost identical for brakes from SRAM, Tektro and other large manufacturers.
How to change disc brake pads on a bike
Tools you need to replace disc brake pads
- Pad pusher tool or ‘fat’/wide flathead screwdriver
- Needle-nose pliers, flat head screwdriver or appropriately sized hex key
- Paper cloth
- Disc brake cleaner
- Replacement pads
Step 1. Inspect for wear
Remove the wheel from the bike and check the brake pads for wear.
It’s important to check the pads regularly – if they wear out right down to the backing plate, metal-on-metal contact will destroy brake rotors very quickly.
Be careful not to actuate the brakes at this stage. Squeezing the brake lever after you’ve removed the disc rotors can force the pistons beyond their limits and compromise the hydraulic system, forcing you to bleed the brake unit.
You should replace your pads when there’s 1.5mm or less of braking material remaining. If the pads are okay, replace the wheel and keep riding. If not, follow these steps.
Step 2: Remove and clean
Start by pushing the old pads into the caliper with a pad pusher tool or a large flat head screwdriver. You must do this at this stage because pushing on new pads directly onto the pistons can cause damage.
Remove the pad retention system – some brakes use a split pin that can be removed with a pair of pliers, whereas others will have a hex- or flat-head screw-in pin. Either way, you need to remove this.
Remove the pads and springs using needle-nose pliers. At this point it’s a good idea to clean the inside of the caliper and rotor with a little degreaser and paper cloth, to remove any brake dust or dirt build-up.
Pay particular attention to the rotor – if it is at all contaminated with oil or grease, this will quickly transfer to your pads, and you’ll have to start the process over again.
Step 3: Replace and adjust
Install the new pads along with the retention pins and clips and return the wheel to the bike. Try to avoid squeezing the brake lever at this point.
Closely examine the caliper position relative to the rotor. The rotor should be running parallel and central to the caliper body. If it isn’t, undo the mounting bolts and adjust so the disc is centred.
Unsure how to centre a caliper? Check out our walkthrough video on how to do this here.
When you’re absolutely sure that the disc is running straight, spin the wheel and squeeze the brake lever. It might take a few pumps before the pads bite. If they don’t grip the rotor after repeated pumps then you will need to bleed the brakes.
When you’re happy that the pads are stopping the wheels properly, you will need to ‘bed them in’.
This can be done by riding in a safe car-free area. Bring the bike up to speed and brake hard. Repeat the process a few times and the bike will be ready to ride.