How to Change Bike Brake Pads: A Step-by-Step Guide to Safe, Smooth Braking

If your bike’s brakes feel mushy, make squealing noises, or take longer to stop than they used to, it’s likely time to replace the brake pads. Worn brake pads don’t just compromise your ride—they put you at risk. Changing them yourself is straightforward if you follow the right steps, and doing so saves you money while keeping your bike in top condition. In this guide, I’ll walk you through everything you need to know: when to replace brake pads, the tools you’ll need, how to handle different brake types (V-brakes, mechanical disc brakes, hydraulic disc brakes), and pro tips to ensure your new pads perform reliably. By the end, you’ll be equipped to tackle this repair confidently and get back to riding safely.

Step 1: Know When It’s Time to Replace Your Brake Pads

Brake pads wear down over time, but the exact timeline depends on how often you ride, the terrain (e.g., mountainous vs. flat), and the type of pads you use. Here are the key signs it’s time for a replacement:

  • Visible wear indicators: Most brake pads have a small metal “wear line” or groove molded into the friction material. If this line is nearly gone or the material looks thin (less than 1–2mm thick), replace them immediately. For resin (organic) pads, the wear indicator might be a dimple; once it’s flush with the surface, it’s time.
  • Reduced stopping power: If you have to squeeze the brake lever harder than usual to slow down, or if your bike doesn’t come to a stop as quickly as it should, worn pads are often the culprit.
  • Squealing or grinding noises: Squealing usually means the brake pads are glazed (hardened from heat) or dirty. Grinding, however, is a red flag—it could indicate that the metal backing of the pad is rubbing against the rotor (for disc brakes) or rim (for rim brakes), which damages components permanently.
  • Rim or rotor damage: For rim brakes, if the brake pads have worn through the friction material and are scraping the metal rim, you’ve waited too long. Similarly, for disc brakes, deep grooves or cracks in the rotor mean you need new pads and possibly a rotor resurfacing or replacement.

Step 2: Gather the Right Tools and Materials

Before you start, make sure you have everything you need. Having the correct tools prevents frustration and ensures you don’t strip bolts or damage your bike.

Essential tools:

  • Allen wrenches (hex keys): Most brake pads are held in place with 4mm, 5mm, or 6mm hex bolts. A multi-tool or a set of hex keys will work.
  • New brake pads: Match the type (V-brake, mechanical disc, hydraulic disc) and size to your bike. Check your old pads for part numbers or measure the width/length to confirm.
  • Rubbing alcohol or brake cleaner: To clean dirt, grease, or oil off the brake rotor (disc brakes) or rim (rim brakes).
  • Sandpaper (optional): If your new pads are resin-coated and sticky, lightly sanding the friction surface with 120-grit sandpaper removes the coating, improving bite.
  • Gloves: Brake pads contain chemicals (like resin or metal shavings) that can irritate skin, and grease from your hands can contaminate new pads.

Additional tools (depending on brake type):

  • For hydraulic disc brakes: A bleed kit (if you need to replace old fluid) and possibly a torque wrench to avoid over-tightening bolts.
  • For mechanical disc brakes: A cable tension adjuster (if your lever feels loose) or a fourth-hand tool to help align the caliper.

Step 3: Prepare Your Workspace

Safety first. Start by parking your bike on a stable surface. Use a bike stand, or flip it upside down (seat and handlebars down) so it rests securely on the tires. If flipping it, make sure the wheels are straight to avoid damaging the brakes during removal.

Next, clean the brake area. For rim brakes, wipe down the rims with rubbing alcohol to remove dirt, oil, or debris—this prevents new pads from grabbing unevenly. For disc brakes, use a brake cleaner on the rotor to eliminate grease (oil on rotors causes braking issues and can ruin pads). Let everything dry completely before moving on.

Step 4: Replace V-Brake Pads (Common on Mountain and Hybrid Bikes)

V-brakes are popular because they’re simple and effective. Here’s how to swap their pads:

  1. Loosen the brake arm bolts: Locate the two small bolts that hold each brake pad in place (one on the top of the brake arm, one below). Use a 4mm or 5mm hex key to loosen them just enough so you can slide the old pad out. Don’t remove the bolts completely—you’ll need them to secure the new pad.

  2. Remove the old pad: Gently pull the pad away from the rim. If it’s stuck, wiggle it slightly or use a flathead screwdriver to pry it loose (be careful not to scratch the rim).

  3. Inspect the brake shoe: The brake shoe is the metal holder for the pad. Check for rust, cracks, or debris. Wipe it clean with a rag—if there’s old glue or residue, use sandpaper to scuff it smooth. This helps the new pad adhere better.

  4. Install the new pad: Align the new pad with the brake shoe. Most pads have a “direction” marker (an arrow or notch) indicating which way they should face (usually toward the front of the bike). Press the pad into place until it’s seated flush with the shoe.

  5. Tighten the bolts: Snug the top and bottom bolts with your hex key. Be careful not to overtighten—one common mistake is stripping the threads. Tighten just enough so the pad doesn’t move when you wiggle it, but leave a tiny bit of play (you’ll adjust this later).

  6. Adjust the brake alignment: Squeeze the brake lever to bring the pads into contact with the rim. If the pads rub unevenly (one side touches first) or the lever feels loose, use the barrel adjuster on the brake lever to fine-tune. Turn the adjuster counterclockwise to move the pads closer to the rim; clockwise to move them away. Repeat until the pads center evenly on the rim and the lever feels firm but responsive.

Step 5: Replace Mechanical Disc Brake Pads

Mechanical disc brakes use a cable to activate the caliper, similar to V-brakes but with a rotor instead of rims. They’re common on hybrid and some mountain bikes.

  1. Release the brake lever: Squeeze the brake lever fully to engage the caliper, then loosen the caliper bolts (usually two 5mm hex bolts) with an Allen wrench. This makes it easier to remove the old pads.

  2. Remove the old pads: Slide the pads out of the caliper. Some calipers have a spring clip holding the pads in place—gently lift this clip off before removing the pads. Set the old pads aside.

  3. Inspect the caliper and rotor: Wipe the rotor with rubbing alcohol to remove dirt or oil. Check the caliper piston(s)—if they’re stuck or corroded, use a piston tool or a flathead screwdriver to gently push them back into the caliper. Corroded pistons can cause uneven braking, so take time here.

  4. Prepare the new pads: If your new pads are “pre-bedded” (coated with a material to improve initial bite), you may need to remove the coating by lightly sanding the friction surface with 120-grit sandpaper. This step isn’t necessary for all pads, so check the manufacturer’s instructions.

  5. Install the new pads: Insert the pads into the caliper, making sure they’re seated correctly. The pad with the spring clip (if applicable) should go back into its original position. Gently press the pads together to compress the springs, then slide them fully into the caliper.

  6. Reinstall the caliper: Align the caliper over the rotor so it’s centered. Tighten the caliper bolts in a crisscross pattern (top then bottom, or vice versa) to ensure even pressure. Start with a loose turn, then tighten to the manufacturer’s torque spec (usually around 6–8 Nm). Overtightening can warp the rotor or crack the caliper.

  7. Bleed the brakes (if needed): If your brakes feel spongy after installation, air may have gotten into the hydraulic line. Bleeding removes air bubbles and ensures consistent pressure. This step requires a bleed kit and some practice—if you’re unsure, take your bike to a professional.

Step 6: Replace Hydraulic Disc Brake Pads

Hydraulic disc brakes are common on high-end mountain bikes. They use fluid (not cables) to activate the caliper, offering stronger, more consistent braking. While they’re low-maintenance, replacing the pads is a bit more involved.

  1. Remove the wheel: Hydraulic disc brakes require the wheel to be removed to access the pads. Flip the quick-release lever (or unscrew the thru-axle) and slide the wheel out.

  2. Push the caliper pistons back: Use a piston tool or a flathead screwdriver wrapped in a cloth (to protect the piston face) to push both pistons fully into the caliper. This creates space for the new, thicker pads. If the pistons are stuck, apply a small amount of brake fluid to the edge of the piston to lubricate it—never use WD-40 or other solvents, as they can damage seals.

  3. Remove the old pads: Most hydraulic calipers have a retention clip or spring holding the pads in place. Use a flathead screwdriver to lift the clip off, then slide the old pads out. Set them aside.

  4. Clean the caliper: Wipe the inside of the caliper with rubbing alcohol to remove dirt, oil, or old fluid. Check the brake fluid level in the reservoir (located on the handlebar). If it’s low, top it up with the manufacturer-recommended fluid—low fluid can cause piston damage.

  5. Install the new pads: Insert the new pads into the caliper, aligning them with the piston faces. The pad with the metal tab (if present) should face the outside of the caliper. Gently press the pads together to compress the pistons slightly, then slide them fully into place.

  6. Reinstall the retention clip: Snap the clip back into position to secure the pads. Make sure it’s seated evenly—if it’s crooked, the pads may rub against the rotor.

  7. Reinstall the wheel: Slide the wheel back into the dropouts, ensuring it’s straight. Tighten the quick-release or thru-axle to the recommended torque (usually 10–15 Nm for quick-releases, 40–50 Nm for thru-axles).

  8. Bed in the brakes: New hydraulic pads need to be “bedded” to transfer friction material to the rotor, which improves braking performance. To bed them in: Ride slowly, then squeeze the brake lever firmly (without locking the wheel) for 5–10 seconds. Repeat 5–10 times, gradually increasing pressure. This process heats the pads and rotor, bonding them together.

Step 7: Test and Adjust After Installation

No matter which brake type you’re working on, testing is critical. Here’s what to do:

  1. Check pad alignment: Spin the wheel and squeeze the brake lever. The pads should make contact with the rotor or rim evenly—no rubbing on one side only. If they rub unevenly, adjust the caliper position (for disc brakes) or the brake arm tension (for V-brakes).

  2. Test stopping power: Ride in a safe, open area (like an empty parking lot). Start with light presses on the brake lever and gradually increase pressure. The bike should stop smoothly without pulling to one side. If it pulls, check for uneven pad wear or a contaminated rotor/rim.

  3. Listen for noises: Squealing can be caused by dirty pads/rotors, loose bolts, or misalignment. If the noise persists after cleaning and adjusting, sand the pads lightly or replace them (if they’re glazed). Grinding means metal-on-metal contact—stop riding immediately and inspect for damage.

Common Problems and How to Fix Them

Even with careful installation, issues can arise. Here’s how to troubleshoot:

  • Brakes feel spongy: For hydraulic systems, this usually means air is in the lines—bleed the brakes. For mechanical systems, check the cable tension (adjust with the barrel adjuster) or lubricate the cable with silicone spray.
  • Pad rubs constantly: The caliper isn’t centered. Loosen the caliper bolts slightly, squeeze the brake lever to align the pads with the rotor, then retighten the bolts.
  • Pads wear out too quickly: This could be due to riding in wet/muddy conditions (which accelerates wear), using the wrong pad material (e.g., resin pads on rough terrain), or misaligned pads (which cause uneven friction). Switch to a more durable pad (like metal) if you ride off-road often.

Final Tips for Long-Lasting Brake Pads

  • Clean your brakes regularly: Wipe down rims/rotors with rubbing alcohol after wet or muddy rides to prevent dirt buildup.
  • Avoid contaminating pads: Never touch the friction surface of new pads with your bare hands—oil from your skin reduces braking power.
  • Replace pads in pairs: Always change both front and rear pads at the same time—even if one set looks newer. Uneven wear causes imbalanced braking.

Changing your bike brake pads is a skill every rider should master. By following these steps, you’ll save money, improve your bike’s performance, and most importantly, stay safe on the road or trail. Remember, if you’re ever unsure about a step (especially with hydraulic brakes), don’t hesitate to consult a professional mechanic—your safety is worth it.

Back to blog