Brake systems come in two forms: disc and drum, and they both work using friction and resistance.
Drum brakes:
- The brake system is in a round drum
that rotates with the wheel.
- Inside the drum are a set of shoes.
- The shoes forced against the drum when the brake pedal is pressed.
- The shoes are made of a heat resistant friction material.
Disc brakes:
- The brakes are setup with a rotor connected to the wheel.
- Brake pads squeeze the rotor and cause friction, which stops the wheel from spinning.
In the course of time the friction will wear down the brake pad, which is why they must be checked or replaced on a regular basis.

Calipers apply pressure to the brake and are powered by a hydraulic system:
- The hydraulic system consists of a master cylinder, hoses filled with brake fluid, and calipers a.k.a wheel cylinders.
- Brake pads can be 8, 10 or 12 mm thick.
- When the pad wears down to 3 mm it needs to be replaced.
- Rotors will also wear down over time, and when the thickness is too low to consume the heat, they will have to be replaced.