What are Brake Pads and Why are They Important?

All cars with disc brakes have brake pads. (Drum brakes have shoes, not pads.) A rotor has one brake pad on each side. The brake pads’ purpose is to create friction to stop the car.

How Brake Pads Work

All brake pads have two main parts:

  1. A steel backing plate that provides a way to mount the pad in the caliper.
  2. A 12 mm (or half an inch) thick friction material.

Additionally many OEM brake pads are provided with additional components.

  • Shims - The inside shim goes between the inside pad backing plate and the caliper piston. The outside shim goes between the outside pad and the caliper body. Shims are there to help prevent noise when braking.
  • Mounting clips - Many brake pads use spring steel mounting clips to help position the pad correctly within the caliper.

The size and shape of shims and mounting clips will vary a lot from vehicle to vehicle. They should be replaced when the pads are replaced.

Mazda brake pads

Brake pads are made from a variety of materials. Some materials are best for spirited driving, others are suited for stopping heavy loads, and others are designed to be quiet and smooth in everyday use. Car manufacturers chose the material based on the intended use of the vehicle. The most common friction materials for brake pads are:

  • Organic: Natural materials like rubber and glass mixed with resin to create resistance to high heat
  • Ceramic: Ceramic fibers, filler material, and bonding agents that are designed to withstand and dissipate heat effectively
  • Metallic (the most common type): Iron, copper, steel, and graphite all bonded together

Two brake pads are mounted in a caliper, one one each side of the rotor. When you hit the brakes, the caliper squeezes the pads against the rotor to provide enough friction to stop the car.

What Happens When Your Brake Pads Wear Out

Brake pads typically last about 50,000 miles. When they start to wear out, you’ll know. All modern brake pads have a wear indicator that makes a high pitched squeal when the pad is getting worn down. DO NOT IGNORE THIS. If the pad wears completely away, the steel backing plate will rub on the rotor and ruin it very quickly. There are other symptoms of worn pads:

  • A grinding noise when braking
  • Vibration coming from the affected wheel when braking
  • The car pulling to one side when braking
  • A spongy feeling when you hit the brake pedal

When your brake pads are almost worn out, they won’t be able to grip the rotor as much as needed and this drastically reduces your car’s stopping power. Most of the time, the pads on the front wheels will wear out before those on the rear wheels, as the front wheels provide most of the stopping power. Also, the pads on the one side of the car usually wear out at the same rate as those on the other side. If you see one set of pads wearing much faster than those on the other side of the car, you might have another problem. A seized brake piston or corroded guide pins can cause uneven wear.

Luckily, brake pads are affordable and easy to replace, which is something you can do without a lift (although it’s much easier with a lift).

How to Replace Your Brake Pads

Protege brake pad change

Image Credit: Johnnysshop

The process involves removing the wheel, loosening the calipers, and then replacing the worn brake pads with new ones. This project should take the average person about 20 or 30 minutes per brake to complete. You should always replace brake pads in pairs. For example, both front wheels or both rear wheels. If you don't, the vehicle will pull in one direction when braking.

Of course, you’ll need replacement brake pads before starting the project. You can order a pair online at a reasonable price. OEM brake pads are highly recommended because they come with the correct pad material that was chosen to suit the needs of you and your vehicle.

Many aftermarket brake pads come with a cheap generic brake pad material. This can lead to the brake pads not performing as well as OEM pads and wearing out faster than normal. Also, many aftermarket pads either come with no shims at all, or generic shims. Many times the spring clips are not included at all. New spring clips and shims should be installed whenever new pads are installed. Reusing old shims and clips, or generic parts, can lead to noisy brakes from the first stop.

Here are a few quick links to some of our most popular OEM brake pads:

  • Part No. L2Y6-33-28ZA: For 2007-2015 Mazda CX-7 and CX-9 front pads
  • Part No. B6YS-33-28ZA: For 2014-2018 Mazda 3 and CX-3 front pads
  • Part No. C2Y3-26-48ZB: For 2004-2015 Mazda 3 and 5 rear pads
  • Part No. G4YA-33-28ZA: For 2014-2017 Mazda 6 front pads
  • Part No. GHY9-26-48ZC: For 2014-2017 Mazda 6 rear pads