The two-sided, open design of disc braking systems creates several advantages over drum systems: Better cooling action, better wet performance, less prone to locking—and, for the DIYer, easier to service.
Parts of a Disc Brake System: Brake Rotors
Disc-shaped rotors spin with the wheel and provide the braking surface. Usually made from cast iron (or a few other high-performance materials), they absorb and dissipate the heat generated from the friction used to slow the vehicle. Vented rotors cycle air through the rotor to speed the release of heat and keep the brake pads cooler. Optional cross-drilling accentuates the cooling action, while slotting vents gas and debris away from the rotor surface, where they can hinder friction between the brake pad surface and the rotor.
Parts of a Disc Brake System: Brake Pads
As you brake, the pads grip the surface of the rotors, creating friction that converts the vehicle’s kinetic energy to heat and slows the vehicle. Here are some causes and diy fixes for smoking brakes.
Parts of a Disc Brake System: Brake Calipers
Brake calipers straddle the edge of each rotor, holding a pad on either side. They are connected to the brake lines, and convert the hydraulic pressure created by the master cylinder to movement, using a piston. The piston squeezes the pads against the rotor, slowing it and generating heat.