4.1 brakes

Disc Brake Pad Replacement

Disc Brake Pad Replacement. Step-by-step procedure for bike maintenance — tools, time, and what to watch out for.

Difficulty ★★☆ moderate
Time ~15 min
Applies to Bikes with hydraulic disc brakes (most modern Gravel, MTB; many Road and E-bike)

Tools

  • Hex or Torx for pad retaining pin (varies — often 3mm hex or Torx T10)
  • pad spreader / piston press
  • new pads
  • optionally a paper towel and isopropyl alcohol

Procedure

  1. Remove the wheel

    from the side you're servicing.

  2. Locate the pad retaining mechanism:

    - Most calipers use a small pin held by a hex bolt or threaded pin, sometimes secured with a cotter pin/clip. - On Shimano: usually a threaded pin with a cotter pin (split pin) through the end. Bend the cotter straight, pull out, then unscrew the pin. - On SRAM: usually a Torx T10 bolt at the top of the caliper. - On Magura: a screw-in pin with hex head.

  3. Remove the cotter pin and retaining pin

    entirely.

  4. Pull the old pads out

    . They typically pull straight up out of the caliper (the slot they sit in is open at the top). The spring (a small stainless wishbone) usually stays clipped between them — note its orientation.

  5. Inspect the pads.

    Replace if the friction material is at or below **1 mm** thick as a conservative app threshold; some manufacturers allow less, such as 0.5 mm, so always confirm the brake manufacturer's minimum. Inspect for contamination — if oily or shiny, the rotor or pads are contaminated and just replacing pads won't fix it (clean rotor with isopropyl, replace pads).

  6. Push the pistons back into the caliper

    using the pad spreader tool (or a clean plastic tire lever): - Insert the spreader between the pistons. - Pry gently and evenly to push both pistons back fully into their bores. - This creates space for the new (thicker) pads. If you skip this step, the new pads won't fit between the rotor and caliper.

  7. Wipe the inside of the caliper

    clean with a dry rag.

  8. Insert the new pads

    with the spring clipped between them. Slide them up into the caliper from below until they sit fully seated.

  9. Insert the retaining pin

    through the caliper, through the holes in the pads (and through the spring).

  10. Secure the pin

    — tighten the threaded portion or reinsert and bend the cotter pin.

  11. Reinstall the wheel.

  12. Squeeze the brake lever several times slowly.

    This advances the pistons until the pads contact the rotor. The first squeeze will feel limp, then progressively firmer.

  13. Bed in the new pads

    (4.2). ---

Procedure #

  1. Remove the wheel from the side you’re servicing.
  2. Locate the pad retaining mechanism:
    • Most calipers use a small pin held by a hex bolt or threaded pin, sometimes secured with a cotter pin/clip.
    • On Shimano: usually a threaded pin with a cotter pin (split pin) through the end. Bend the cotter straight, pull out, then unscrew the pin.
    • On SRAM: usually a Torx T10 bolt at the top of the caliper.
    • On Magura: a screw-in pin with hex head.
  3. Remove the cotter pin and retaining pin entirely.
  4. Pull the old pads out. They typically pull straight up out of the caliper (the slot they sit in is open at the top). The spring (a small stainless wishbone) usually stays clipped between them — note its orientation.
  5. Inspect the pads. Replace if the friction material is at or below 1 mm thick as a conservative app threshold; some manufacturers allow less, such as 0.5 mm, so always confirm the brake manufacturer’s minimum. Inspect for contamination — if oily or shiny, the rotor or pads are contaminated and just replacing pads won’t fix it (clean rotor with isopropyl, replace pads).
  6. Push the pistons back into the caliper using the pad spreader tool (or a clean plastic tire lever):
    • Insert the spreader between the pistons.
    • Pry gently and evenly to push both pistons back fully into their bores.
    • This creates space for the new (thicker) pads. If you skip this step, the new pads won’t fit between the rotor and caliper.
  7. Wipe the inside of the caliper clean with a dry rag.
  8. Insert the new pads with the spring clipped between them. Slide them up into the caliper from below until they sit fully seated.
  9. Insert the retaining pin through the caliper, through the holes in the pads (and through the spring).
  10. Secure the pin — tighten the threaded portion or reinsert and bend the cotter pin.
  11. Reinstall the wheel.
  12. Squeeze the brake lever several times slowly. This advances the pistons until the pads contact the rotor. The first squeeze will feel limp, then progressively firmer.
  13. Bed in the new pads (4.2).