Brake Maintenance

Brake Maintenance

Your road bike’s braking system is vital to both safety and control. Responsive brakes help you descend with confidence, stop quickly in emergencies, and maintain smooth handling in all conditions. Whether you're running rim brakes or disc brakes, regular maintenance ensures consistent performance and prevents costly wear.

Here, we’ll look at what to check during regular inspection, and then walk through key maintenance tasks for both brake types with tools and step-by-step guidance.

a. Why Brake Maintenance Matters

  • Safety
    • Efficient brakes reduce stopping distance and help avoid accidents.
  • Control
    • Responsive braking lets you ride more confidently in descents, corners, and traffic.
  • Component Longevity
    • Clean pads and brake surfaces prevent excessive wear to rims or rotors.

Pro tip: Perform a quick brake check before every ride, and do a full brake system service every 3–6 months or if performance changes.

b. What to Look Out For

During cleaning, before rides or during routine checks, inspect for:

  • Brake functionality: Do not ride if brakes don't work.
  • Brake stopping time: Brakes should engage quickly & stop wheel with even force.
  • Pad wear: Pads should not be worn past indicators or below 1mm.
  • Brake track or rotor condition: No deep grooves, glazing, or contamination.
  • Rubbing: Wheels should spin freely without pad contact.
  • Cable or hose condition: No fraying, cracking, or visible damage.

1. Rim Brakes: Maintenance & Adjustment

a. What You'll Need:

  • 4mm or 5mm hex key (for pad and caliper bolts)
  • Isopropyl alcohol and clean cloth
  • Brake pad wear guide or ruler
  • Sandpaper or file (optional)
  • Replacement brake pads (cartridge or block)

b. Check and Replace Pads: Step-by-Step

  1. Inspect pad grooves or wear indicators.
  2. Slightly smoothed or glazed pads can be roughened with sand paper.
  3. Worn-down, hardened or completely glazed should be replaced:
    1. Use hex key to loosen bolts and remove pads.
    2. Insert new pads, align to rim surface, and torque bolts (typically 5–7 Nm).

c. Align Pads: Step-by-Step

  1. Pads should contact the braking surface only, not the tyre or below the track.
  2. Slightly toe-in the front edge (1–2mm) to reduce squealing:
    1. Angle the front of the brake pad slightly closer to the rim than the rear.
    2. This helps reduce vibration and brake squeal by allowing the pad to engage the rim more smoothly and gradually.

d. Center the Caliper: Step-by-Step

  1. Spin the wheel and check for rubbing.
  2. Use centering screw or adjust caliper bolt so pads clear the rim evenly.

e. Clean Pads and Rims: Step-by-Step

  1. Wipe rim and pads with isopropyl alcohol.
  2. Remove metal debris from pads using a pick.
  3. Lightly sand pads if glazed:
    1. Roughing-up pads improves contact and braking.

2. Disc Brakes: Maintenance & Adjustment

a. What You'll Need

  • T25 Torx key (for rotor bolts)
  • 5mm Hex key (for caliper bolts)
  • 2.5mm Hex key (for pad retaining bolts)
  • Pad spacer or tyre lever
  • Threadlock (if required for changing rotor)
  • Isopropyl alcohol or disc brake cleaner
  • Replacement pads (resin or metallic)
  • Bleed kit + mineral oil or DOT fluid (hydraulic only)
  • Replacement pads (resin or metallic)

b. Clean & Inspect Rotors & Pads: Step-by-Step

  1. Wipe rotors with isopropyl alcohol and avoid touching with fingers:
    1. Clean pads if slightly contaminated.
    2. If heavily soaked in oil: replace.
  2. Remove the wheel to inspect:
    1. Rotor wear (minimum thickness ~1.5mm)
    2. Scoring, warping, or discolouration
    3. Pad thickness (replace if below 1mm)

c. Replace Pads: Step-by-Step

  1. Remove the wheel to access the caliper.
  2. Use a pad spacer or tyre lever to gently push pistons back into the caliper.
  3. Remove the retaining pin or bolt using a 2.5mm hex key.
  4. Slide out the worn pads.
  5. Insert new pads, ensuring correct orientation.
  6. Reinsert and secure the retaining pin or bolt.
  7. Reinstall the wheel and check alignment.

d. Replace Rotors: Step-by-Step

Note: You can usually change a rotor without removing the caliper, although you might need to on bike-set-ups with tight clearances.

  1. Use a T25 Torx key to loosen and remove rotor bolts (for 6-bolt rotors) or a cassette lockring tool (for centerlock rotors).
  2. Remove the old rotor.
  3. Install the new rotor in the same orientation (marked "rotation").
    1. Make sure the rotation arrow on rotor goes with forward wheel spin. 
    2. Apply a small amount of threadlock to bolts (if required by manufacturer).
    3. Torque rotor bolts to spec (typically 4–6 Nm for 6-bolt systems).
  4. Spin the wheel to confirm rotor runs true and doesn’t rub.

IMPORTANT: Avoid over-tightening rotor bolts as this may warp rotors and lead to rubbing, squealing or insufficient performance.

e. Center the Caliper: Step-by-Step

  1. Loosen caliper bolts.
  2. Squeeze the brake lever firmly.
  3. While holding the lever, re-tighten bolts evenly.
  4. Spin the wheel and check for rubbing.

3. Replace Brake Cables

Over time, brake cables can become stretched, frayed, corroded, or sticky, especially in wet or dirty conditions. Replacing your cables restores braking performance and lever feel.

Look for a suitable kit that matches the performance desired, lengths needed and if cables are externally or internally routed.

a. What You'll Need

  • Cable replacement kit (compatible with your brake system)
    • Cables (with sufficient length)
    • Cable Housing (with sufficient length)
    • End caps for cable
    • Ferrules (i.e. end caps for housing)
  • Cable cutters
  • For internally routed cables: Quality string (or similiar)
  • 5mm hex key (for brake anchor bolts)
  • Pick (or fine-point tool)
  • Light grease or PTFE lube

b. Replace Brake Cables: Step-by-Step

  1. Remove old cable:
    1. Shift to release cable tension.
    2. Loosen the anchor bolt on the brake caliper.
    3. Cut off the crimped end and pull the cable out from the lever.
  2. Remove housing from frame:
    1. If internally routed, tape string to old cable before removing.
    2. Pull through old cable leaving string in place as guide to route new cable.
    3. Tape ends of string to frame to stop it falling into frame.
  3. Inspect or replace housing:
    1. Check housing for cracks, rust, or kinks.
    2. Replace if damaged, or if shifting/braking felt stiff.
      1. Cut new housing to match the old housing length.
      2. File end of housing smooth with slight rounded edges for ferrules.
      3. Use a pick to open the ends cleanly.
  4. Install new cable
    1. Apply a light coat of grease or PTFE lube to the cable if required.
    2. Thread through the housing and into the brake lever.
    3. Route through frame guides (external) or frame via stops (internal).
  5. Anchor and adjust
    1. Pull the cable taut by hand and clamp under the brake caliper bolt.
    2. Fine-tune with the barrel adjuster at the caliper or lever.
  6. Test and Trim
    1. Pull the brake lever to test tension.
    2. Trim the excess cable and install a cable end cap.
    3. Re-check for even pad contact and lever feel.

Pro Tip: If you do not have a barrel adjuster on shifter or brake caliper, you may wish to add an inline barrel adjuster whilst changing cable for fine-tuning. You will need to make sure you get one for brake cables (rather than shifter cables). See section 6.c. of Derailleur & Drivetrain Maintenance post for details of how to do this.

4. Bleed Hydraulic Brakes

Bleeding removes air bubbles from the hydraulic brake system, restoring firmness and stopping power. If your brakes feel spongy, inconsistent or weaker than usual, it is recommended to perform a bleed.

Look for a brand-specific bleed kit and check which fluid is required. Usually Shimano and Campagnolo systems use different types of mineral oil, SRAM and TRP use DOT brake fluid. Always check what fluid is used in your system. Fluids cannot be mixed and are not interchangeable.

Pro tip: Bleed hydraulic brakes at least once annually, or more often in wet or hilly conditions when temperatures change and brakes used more.

a. What You'll Need

  • Bike stand (optional but recommended)
  • Bleed kit (compatible with your brake system):
    • Fluid
    • Fluid insertion tool:
      • Shimano: usually funnel for lever
      • SRAM: usually two-syringes (push-pull) for lever & caliper
      • Campagnolo: uses specific bleed tools / syringes
    • Fittings (screw-on or snug-fit)
    • Spare seals
    • Additional tools:
      • Bleed block
      • Hose clamps
  • Fluid (if not included in kit):
    • Always double check what fluid is needed 
    • Shimano: usually mineral oil
    • SRAM/TRP: usually DOT brake fluid
    • Campagnolo: usually mineral oil (but different type than Shimano)
  • Bleed block or pad spacer
  • 7mm or 8mm open-ended spanner
  • Catch bottle and clear tubing
  • Clean rags or paper towels
  • Isopropyl alcohol
  • Allen keys (to remove caliper if needed)

b. Bleed Hydraulic Brakes: Step-by-Step

  1. Prep the bike:
    1. Clamp bike securely in a stand.
    2. Remove the wheel and brake pads.
    3. Insert a bleed block or pad spacer into the caliper.
  2. Attach the syringe or funnel, follow your kit's instructions:
    1. For Shimano: screw funnel into lever bleed port.
    2. For SRAM: attach syringe to lever and caliper ports with tubing.
    3. For Campagnolo: method varies between models.
  3. Open Bleed Nipples
    1. At the caliper, attach tubing and catch bottle.
    2. Use a 7mm (or 8mm) spanner to open the bleed port slightly.
  4. Push/Pull Fluid Through
    1. Gently push clean brake fluid from the lever or top port.
    2. At the same time, pull fluid from the caliper syringe to remove air bubbles.
    3. Tap the caliper and hose to dislodge trapped bubbles.
  5. Close System and Clean
    1. Once no bubbles remain, close the bleed nipples tightly.
    2. Remove bleed blocks and reinstall pads.
    3. Wipe down with isopropyl alcohol to clean any residue.
  6. Reinstall Wheel and Test
    1. Spin the wheel and test brake lever.
    2. Lever should feel firm with quick engagement.
    3. If still spongy, repeat the process or check for leaks.

IMPORTANT: Never spray lubricant near rotors or pads. Keep all fluids away from braking surfaces.

5. Top Tips Round-Up

  • Always clean braking surfaces with isopropyl alcohol, not degreaser.
  • Try toe-in adjustment or sanding glazed pads if rim brakes squeal.
  • Replace disc brake pads if they’re contaminated or below 1mm thickness.
  • Bleed hydraulic brakes once a year or if lever feels spongy.
  • Use a pad spacer when transporting or working on bikes with hydraulic brakes.
  • Never touch brake rotors with bare fingers as natural oils can contaminate braking surfaces.
  • When replacing rim brake pads, always check alignment to avoid rim damage.
  • Test brake feel before every ride and address any change immediately.

Continue reading with Wheel & Frame Maintenance

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