Brake pads are flat friction components housed inside the brake caliper. When you press the brake pedal, hydraulic pressure forces the caliper pistons to squeeze the brake pads against the rotor (disc). This friction is responsible for slowing the wheel to stop the vehicle.
Think of them as the shoes that grip the spinning disc.
⚙️ How Brake Pads Work
- Press the brake pedal → master cylinder sends hydraulic fluid pressure.
- Caliper pistons push brake pads toward the spinning rotor.
- Pads clamp the rotor on both sides.
- Friction converts kinetic energy → heat → slowing the vehicle.
🛠️ Types of Brake Pads
- Organic (Non-Asbestos Organic / NAO)
- Made from rubber, glass, resins, and fibers.
- Quiet, affordable, gentle on rotors.
- Wear faster, less effective under extreme heat.
- Semi-Metallic
- Contain 30–65% metal (steel, iron, copper).
- Excellent braking power, durable, good heat dissipation.
- Louder, harder on rotors, produce more dust.
- Ceramic
- Made from ceramic fibers, nonferrous fillers, bonding agents.
- Long-lasting, quiet, low dust, high performance.
- Expensive, not ideal for very cold climates.
- Low-Metallic NAO
- Organic pads with small amounts of copper/steel.
- Good braking and heat transfer.
- Can be noisy and dusty.
🧩 Structure of a Brake Pad
- Friction Material – The part that contacts the rotor.
- Backing Plate – Steel plate that supports the friction material.
- Shims & Insulators – Reduce noise and vibration.
- Wear Indicator – Metal tab that squeals when pads are worn.
⚠️ Common Brake Pad Problems
- Worn Pads – Reduced thickness = weak braking & rotor damage.
- Glazing – Overheating causes pads to harden, reducing friction.
- Uneven Wear – From seized calipers or misalignment.
- Noise (squealing/grinding) – Signals worn pads or rotor damage.
⏱️ Brake Pad Lifespan
- Average: 30,000–70,000 miles (48,000–112,000 km).
- Depends on driving style, vehicle type, road conditions, and pad material.v