Brake pads and brake discs

Just like that of a pedal bike, a modern car’s braking system is made up of three main components; calipers, pads and discs. The caliper is the part you can see first and foremost and is the part of the system that creates friction and acts as a clamp around the disc. These calipers are often painted in bright colours on sportier cars to emphasize the theme of performance.

Brake pads are the part of the whole system that usually need replacing first since they are made of a softer material than the discs, and therefore wear much quicker as they are essentially eroded away by the metal discs.

What are brake pads and brake discs for in a car?

When you step on a brake pedal, the brake pads and discs come to gather and causes friction. By converting the friction energy to heat energy, the car is able to safely slow down. This is how braking works.

Attached to either side of a caliper are the brake pads; the materials that make contact with the discs under braking. The discs themselves are fitted to the inside of your car’s wheels. As you apply pressure to the brake pedal, brake fluid pushes a piston against the caliper, causing it to squeeze the pads against the disc. This in turn slows the turning wheel and therefore, the car down.

A brake disc is usually an iron (or carbon composite) disc that is attached to the suspension of a car, motorcycle or even bicycle and is gripped by brake pads held in a brake caliper.

The friction between the brake disc and the pads is what brings the car to a halt.

The brake disc has numerous advantages over the brake drum, because it dissipates heat quickly, giving strong and consistent braking performance.

Disc brakes also give the driver more ‘feel’ at the pedal, allowing him or her to more easily modulate the pressure for a smooth stop.

In higher-performance applications, a brake disc will actually comprise two discs attached side by side by various rotors.

This, in effect, makes the disc ‘ventilated’ further helping cooling and performance.

Types and characteristics of brake pads

Semi-Metallic. Perhaps the most commonly found brake pads, semi-metallic models consist of between 30% and 65% metal... Ceramic... Low-Metallic NAO... Non-Asbestos Organic...

They are mainly composed of a relatively large amount of iron powder and steel fibers, some graphite, rubber, organic fibers, ceramic materials, abrasives, lubricant and filler. The mixture is bonded together by a thermosetting phenolic resin.

Key varieties of brake pads

There are three main types of brake pads that you'll find on passenger vehicles: non-asbestos organic, ceramic and semi-metallic.

Non-asbestos fibers include aramid, Kevlar and fiberglass. Aramid is often used for its excellent heat resistance and strength. The natural material is up to five times stronger than steel and twice the strength of glass fiber or nylon.

Semi-metallic brake pads can be noisier than ceramic brake pads and their price point normally falls between that of organic and ceramic brake pads. Ceramic brake pads, while quieter, are also able to handle extremely high temperatures with quick recovery, causing less damage to the brake rotors.

With paint correction completed prior to application, it can improve the shine of the vehicle's paint, block UV rays, and provide a protective coating that can last years.

The nuances of maintaining and operating brake pads

To avoid rough and harsh operation of brake we maintain the serviceability of brake pads. Over time the use of your brakes causes normal wear and tear, which can render them ineffective or useless. It’s important to have regular maintenance performed on your braking system to keep it in tip top shape, and provide safe driving conditions for you and your family.

Brake discs: construction and characteristics

The characteristic of a brake system includes peak force, continuous power dissipation, fade, smoothness, power, pedal feel, drag, durability, weight, and noise. Some other factors that are listed may be considered as the characteristic of a brake system.

The brake rotor (disc) which rotates with the wheel, is clamped by brake pads (friction material) fitted to the caliper from both sides with pressure from the piston(s) (pressure mechanism) and decelerates the disc rotation, thereby slowing down and stopping the vehicle.

Classification of brake discs

Based on the working principle used brakes can be classified as mechanical brakes, hydraulic brakes, electrical (eddy current) magnetic and electro-magnet Brake discs are classified into carbon fiber ceramic brake discs and metal brake discs according to different materials. However, due to the high manufacturing cost of carbon fiber ceramic brake discs and the poor braking force at low temperatures, although they have excellent heat decay resistance, they still have excellent heat resistance. Not used by most vehicles. In order to increase the resistance to heat decay, some manufacturers also use carbon fiber brake discs for carbon fiber treatment to improve their ability in this area, while avoiding the problem of poor low temperature performance of carbon fiber ceramic materials.

When should I change my brake discs and brake pads?

On average, brake pads should be replaced every 25,000 to 65,000 miles, while rotors typically should be changed anywhere from 30,000 to 70,000 miles. However, the exact number can differ depending on driving conditions and styles.

It might not always seem necessary to replace brake pads when you're getting brake discs changed, but it tends to work out for the best. As a general rule, it's recommended that if your brake pads are half worn down, get them changed at the same time as the discs.

Sources of information