Car Brake Parts 101

Your car’s brake system is the most important safety system in your car. It gives you control of the vehicle and lets you stop gradually or suddenly, keeping everyone safe.

There are a few different kinds of brake systems, each containing many working parts, but the main principle in each system is using friction against the wheels to slow down.

What are these different car brake system components? We go over each one, and things to look out for when maintaining them (such as in a regular service).

An overview of brake system components

Your car’s brakes are made up of a mechanical ecosystem, where all moving parts need to rely on each other to function as one. There are many components to this that work together to stop your car, including:

Below we’ll go into a bit more detail about how some of these parts work.

What are rotors in a car?

Rotors, otherwise known as brake discs, are the last part of the braking process where all the hydraulic power of the braking system is directed. They’re located on each wheel hub that uses a disc braking system.

When you brake, this results in callipers with brake pads attached squeezing down on the edge of these rotating discs to slow the car through friction. There are a few different types of rotors: drilled, slotted, drilled and slotted, and smooth.

Each type suited for different driving conditions.

What are brake pads?

Brake pads are parts of the disc braking system providing the friction needed to stop your car. They come in a variety of different materials like ceramic, organic, semi-metallic, and full metallic, which are all safety rated. They differ in how quiet they are, how long they last, and how much dust they produce.

What are brake pistons?

The piston sits inside the calliper, pushing against the brake pad to make it grip the spinning rotor to slow down your car. They can be made from metal or high strength phenolic resin, the advantage of resin being that the piston will transfer less heat to the brake fluid while being more resistant to corrosion and is lighter.

What is a car brake caliper?

The brake caliper, or calliper, is part of the disc brake system and is what carries the brake pads, to press down on your rotor to slow your car. It’s a bracket on the edge of the rotor, which helps to create the friction needed to stop the rotor spinning, housing the inner and outer brake pad.

What part does brake fluid play in the brake system?

Brake fluid is an essential component in the brake system. It’s a non-compressible hydraulic fluid that is used to increase the braking force applied to the pedal, as well as lubricating parts of the braking system. It needs to withstand high temperatures and comes in different grades depending on your vehicle's needs and should be changed every 2 years regardless of the amount of driving that you do.

Different car brake types

Cars today use one of two kinds of brake systems: drum brakes or disc brakes. Both styles have been around for over 100 years, and each have their own benefits. Let’s take a look at how they differ.

What is a drum brake?

Drum brakes work by creating friction between an internal brake shoe and a rotating outer drum to slow the car down. They’re an older system than disc brakes, and are mainly used on the rear wheels of modern cars, as they’re cheaper to make.

Although disc brakes give better performance, the front wheels do 90% of the braking, with the rear brakes mainly providing stability, so this is often considered a good trade-off between performance and cost.

What is a brake disc?

Also known as a rotor, the brake disc is one of the main disc brake components. They work on similar principles as drum brakes, using friction to slow the car, however it’s the brake pads that cause friction, with callipers that grip the brake disc.

This system has several advantages. Firstly, if you drive through water and it can get into your drum brake, it tends to make the brakes slip because the water pools inside the drum. With disc brakes however, the squeezing action of the callipers and being an open system means that the water quickly drains away. Another advantage is disc brakes are better at dissipating heat, which makes them more reliable long-term for more consistent braking performance.

How to know if you need brake replacements

How long your brakes last depends on a lot of factors including driving style, pad material, and the type of brake system you have - as well as overall vehicle condition, type and weight. But if you’re wondering if replacing brakes is something you need to budget for soon, come down to your local mycar if you notice:

Need a brake? Call one of our trusted mycar mechanics and we’ll happily talk you through any issues you have, and book you in for brake replacement.