How to Change Brake Pads on a 1999 Yamaha PW50

Shop parts for a 1999 Yamaha PW50 Dirt Bike.

Brake system overview & why it matters

The 1999 Yamaha PW50 is a light youth dirt bike, and like most modern dirt bikes including the PW50 it uses a hydraulic disc brake system on at least one wheel with a brake caliper squeezing pads against a steel rotor. Key components you'll interact with are the brake lever or pedal, master cylinder, hydraulic line, caliper, brake pads, and the rotor. When you pull the lever or press the pedal hydraulic pressure forces the caliper pistons to push the pads against the rotor to slow the bike. Maintaining proper pad thickness and clean components keeps braking predictable, preserves control, and prevents rotor damage.

When to replace brake pads & symptoms of wear

  • Reduced braking power or longer stopping distances
  • Squealing, scraping or grinding noises from the caliper area
  • Excessive lever or pedal travel before braking engages
  • Visible pad material worn thin – backing plate close to the rotor
  • Blue or discolored rotor surfaces from overheating

Inspect pads after muddy rides, long trail days, or if you notice any of the signs above. Youth bikes like the PW50 have lighter braking demands, but worn pads still reduce safety and control.

Tools & parts you'll need

  • New brake pads specific to a 1999 Yamaha PW50
  • Socket set or spanner for axle and caliper bolts
  • Screwdriver or punch for retaining pin/clip
  • Pliers (for cotter pins or clips)
  • Clean shop rags and brake cleaner
  • Small flat tool to compress piston (plastic or wood pad recommended)
  • Torque wrench (recommended for axle and fasteners)

Step-by-step – changing the pads

The order here assumes basic garage setup and common caliper layout on small dirt bikes. Adjust slightly if your PW50 has a different caliper mount or if you're working front versus rear.

  1. Prepare the bike and workspace. Park on level ground, shut off the engine, and remove the key. Gather tools and new pads. Work in a clean, well-lit area.
  2. Support the bike safely. Use a small stand or block under the frame so the wheel you'll work on is off the ground and stable. The PW50 is light & easy to support with a low stand.
  3. Remove the wheel if needed. On some setups you can change pads with the wheel in place; on others removing the wheel gives better access. Loosen axle nut, slide axle out, and remove wheel following the bike's familiar pattern.
  4. Access the caliper retaining hardware. Locate the retaining pin, bolt or clip that secures the pads. On many youth dirt bike calipers this is a simple clip or cotter pin. Remove the retaining clip or pin with pliers or a screwdriver.
  5. Slide old pads out. Pull the pads straight out of the caliper bracket. Note pad orientation and any shims for correct reassembly. If pads are stuck, gently pry using a flat tool while protecting the caliper finish.
  6. Inspect rotor and caliper. Check rotor surface for scoring, warping or excessive thickness loss. Look around the caliper for leaks, dirt, or seized slide pins. Clean dirt and brake dust with brake cleaner and a rag.
  7. Compress the caliper piston(s). Before installing new thicker pads you must push the pistons back into their bores to make room. Use a clean flat tool or pad spreader and press evenly on the piston face until fully seated. Keep brake fluid reservoir cap loosely in place to avoid spills but not sealed to allow fluid return.
  8. Install new pads. Slide new pads into the caliper in the same orientation as the originals. Ensure any anti-rattle clips or shims sit correctly and the pad backing plates contact the caliper properly.
  9. Reinstall retaining hardware. Fit the retaining pin, bolt or clip and secure it to factory tightness. Make sure clips are fully seated and pins are retained so pads cannot shift.
  10. Reinstall wheel & axle hardware (if removed). Refit the wheel, align spacers, and torque the axle nut to a sensible spec for a small bike. Spin the wheel to verify it clears the caliper and rotor without rubbing.
  11. Restore hydraulic pressure. Pump the brake lever or pedal several times until you feel firm resistance. This moves the pads into correct contact with the rotor. Check fluid level in the master cylinder and top if necessary.
  12. Final check. With the bike supported, spin the wheel and apply the brake to ensure consistent engagement and no dragging. Re-torque fasteners after a short test ride.

Helpful inspection tips while you're in there

  • Measure rotor surface condition – deep grooves or a lip at the rotor edge suggest rotor service.
  • Check for brake fluid wetness around the caliper seals – any visible leak requires attention.
  • Ensure caliper slide pins move freely; clean and lightly grease if they're sticky.
  • Remove packed mud or debris from the caliper bracket to prevent pinching new pads.
  • Confirm retaining pin and clips are secure and not bent or worn.

Bedding in new pads

Bedding new pads helps them transfer an even layer of friction material to the rotor for consistent braking. From low speed, perform 8–12 controlled stops from about 10–15 mph to moderate slowing without locking the wheel. Allow the brakes to cool for a few minutes between series of stops. Avoid hard emergency stops until the pads are bedded.

Notes on PW50 braking setups

The PW50 is a small-displacement youth trail/motocross-style bike with lighter braking demands than full-size motocross or enduro machines. That said, the same hydraulic disc principles apply: consistent pad contact and clean components equal reliable stopping. If your model uses a different caliper design for a given generation, the mechanical steps above still apply – removing retaining hardware, compressing pistons, installing pads, and restoring pressure.

Keeping pads inspected and replaced when thin is an easy maintenance task that keeps your 1999 Yamaha PW50 safe and fun to ride.

Related Shopping Categories

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Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your motorcycle's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.