All about Braking System and Its Components

By | September 17, 2014

Brakes are important components in automobiles to control the speed of vehicles. In this article, we will discuss the braking system and their components. Brakes are essential for safety.

About brakes and braking system

  • A brake is a mechanical device that controls motion of an automobile/vehicle by slowing or stopping the moving parts.
  • Braking of a vehicle depends on static function of brakes between tires and road
  • surface.
  • In braking system “The kinetic energy is dissipated in the form of heat energy”.
  • Most brakes use friction between moving parts (wheel or wheel drum) and stationary parts of vehicle (brake shoes).
  • The heat energy generated due to application of brakes is dissipated into air.

Components of braking system in a vehicle
Brake pedal

  • The brake pedal acts as a lever.
  • It’s used to increase the force applied by the driver on the brake pedal pad.
  • It uses a lever to transfer the force from the driver’s foot to the master cylinder.

Brake pads

  • These are the steel plates that are bound with a frictional material facing the rotor. These are mostly used in disc brakes.

Brake lines

  • Brake lines carry the braking fluid from the master cylinder to the brakes.
  • The brake lines transmit a considerable amount of hydraulic pressure to stop the vehicle.
  • These are mostly made of steel and they are attached to the vehicle body with clips to prevent damage from vibration.

Brake shoes

  • These are a pair of steel pieces welded together.
  • A compression spring is placed attached to this shoes so that whenever the brake is applied, the compression spring compresses causing the brake shoes to expand to the brake drum to stop the wheel.

Brake drum

  • It’s a rotating drum-shaped component mounted on the wheel.
  • It is mostly used in drum brakes.
  • The friction between the brake drum and the brake shoes causes the wheel to reduce the speed or stop.

Rotor/brake disc

  • It’s a cast iron material disc which is connected to wheel or axle.
  • With the friction between the brake pads and the brake wheel the motion of the wheel is reduced or stopped.
  • These are also made of reinforced carbon-carbon, and ceramics composite.


  • It’s a moving component which is connected to the master cylinder.
  • It is used to pressurize the braking fluid.


  • The main purpose of the caliper is to slow the vehicles speed by creating friction on the brake disc.
  • The brake caliper fits over the rotor like a clamp.
  • Inside the caliper are a pair of metal plates bonded with friction material called as brake pads.

These caliper are of two types they are as follows

  • Floating caliper
    • It moves relative to the brake disc.
    • It consists of a piston on one side of disc to push inner brake pad into braking surface before pulling caliper body to apply pressure on opposite side of disc.
    • These are also known as a sliding calipers.
  • Fixed caliper
    • It does not move relative to rotor.
    • It uses one or more single pairs of opposing pistons to clamp from each side of the brake disc.

Master cylinder

  • Master cylinder is device which converts the non-hydraulic pressure from your foot into hydraulic pressure.
  • It also controls “slave cylinders” which is at the opposite end of the hydraulic system.
  • It is the most important device pressurizing the braking fluid.

Vacuum servo/brake booster

  • It’s used to enhance the master cylinder and to increases the pressure by driver’s foot by using vacuum in the engine intake.
  • These are effective only when the vehicle’s engine is running.

These are some of the components of the braking system in a vehicle. Proper maintenance of the braking components can prevent brake failure. If you ignore the maintenance of the braking components, it may lead to dangerous accidents.