Disc Brakes Basics: Parts In The Braking System

When you purchase a vehicle, you should take the time to learn about its various systems and components. Doing so can not only help you identify and diagnose various problems before they become costly to fix, and help you perform DIY maintenance and repairs with ease. One system you should get to know intimately is your disc brake system.

Disc Brake Parts: What You Need To Know

When it comes to disc braking systems, there are four parts you need to know: The pads, rotors, calipers, and hardware. The system is responsible for… well, braking. However, as with any other component within your vehicle, each aspect of the braking system serves a different purpose. Knowing what that purpose is can help you ensure your brake system and its parts remain fully functional at all times.

1. Brake Pads

The brake pads are the outermost part of the braking system and true workhorses. The brake pads are one of the brakes components that contact and apply pressure and friction to the brake rotors — the discs that actually slow and stop the vehicle. The pads go under extreme stress every time you slow down and come to a stop, as they control the pace at which your wheels stop turning.

Brake pads are not all created equal. There are two types of brake pads we recommend to vehicle owners:

  • Semi-Metallic: Semi-metallic pads — often called “semi-mets” — provide ultimate stopping power. These pads contain metal fibers used to create the friction with the rotor.
    Semi-metallic brake pads are ideal for towing and heavy duty performance. Semi-mets have a tendency to be noisy and produce a brake dust, and due to their aggressive nature, the rotors generally wear faster.
  • Ceramic: Ceramic brake pads are the most popular option, as they’re durable, provide for significant stopping power and come in ranges of quality. Ceramics use adhesion to provide the stopping power with the rotors, as they leave a layer of sticky transfer on the rotors. These pads are the most common and are used by many auto manufacturers on everything from cars to SUVs.

Ideally, AutoZone recommends that you replace brake pads with the same material that the manufacturer used on your vehicle originally. If your vehicle came equipped with ceramic brake pads but you use your vehicle more for towing or high-heat situations, it may be worth switching to a semi-metallic. If you want to know more about the different kinds of brake pads available to you at AutoZone, read up on the kinds of brake pads to buy guide.

2. Brake Rotors

The brake rotor is the heart of your braking system and therefore should be made of high-quality materials. When performing any type of brake repair, you should always examine your rotors for wear. We recommend replacing rotors with every brake pad change.

Many people try to cut costs on rotor repairs by opting for an economy version. Lower quality metals or lighter rotors do not allow for your braking system to perform at the standards that restores your braking system to that of when it was new, increasing the distance it takes for your vehicle to stop. People also opt for having their rotors turned to save money, taking their rotors below the recommended minimum thickness. This leads to heat being trapped in the brake components, and ultimately leads to premature failure.

If price point is a concern, keep in mind that you will be replacing the same parts at a much shorter interval due to the increased wear and risk of premature failure.

3. Brake Calipers

Calipers have a much longer lifespan than any other part of the braking system parts. Though the lifespan varies based on a number of factors, mechanics and manufacturers generally estimate that calipers can last three to four times longer than brake pads. That said, if your caliper is going out, you want to diagnose the issue early on, before it puts you in harm’s way.

An easy sign to identify that you need to replace the caliper or caliper hardware is if your brake pads show uneven wear. If one end of the pad is thicker than the other, or if one pad has more pad left, then you have an issue. Sometimes uneven wear is simply the result of corroded caliper pins or guide bolts, but if you can freely slide the pins in the caliper bracket, then it points to a caliper issue.

One of the surest signs you’re due for a caliper replacement is a leak. If the presence of brake fluid is visible near the brake line fitting or in the pistons, the caliper has been exposed to the outside elements and needs to be replaced. A torn piston seal creates contaminated brake fluid, which will travel to other parts of the braking system such as other calipers and the master cylinder, and will need to be flushed.

4. Brake Hardware

Aside from the four main brakes components, your brake system contains a few smaller parts. If you’re lucky, your braking problems stems from one of these little guys, which would mean a quick, easy, and affordable fix:

  • Caliper Pins: Most brake calipers contain two pins which help to move the caliper as pressure is applied to the brake pads. Sometimes the pins corrode, which can prevent them from doing their job effectively, and creates uneven wear and early failure of brake pads. Pull the pins and replace contaminated grease to allow them to move freely again. If they are too damaged, replace with new pins.
  • Caliper Pin Boots:The pins mentioned above are installed inside of these rubber boots that allow for movement with protection from the weather and road debris. If torn, they lose their ability to do their job and can cause allow damage to happen in a hurry. Replace all torn or dry rotted boots to keep your system clean and closed.
  • Abutment Clips: Abutment clips are the stainless pieces that the pads slide on within the caliper bracket. You should replace these clips with every brake job, as they are spring loaded and lose their tension and ability to aid the pads over time. We now include these clips in all of our Duralast Gold brake pad boxes.

Once you diagnose your braking issue, head to AutoZone to grab the parts you need to make the repair. If you are having trouble identifying your problem, ask one of our employees to show you which parts are damaged and need to be replaced. If the job is too big for you, seek out one of our Preferred Shops to help you do the job.

Shop Brake Parts

Advice, how-to guides, and car care information featured on and AutoZone Advice & How-To’s are presented as helpful resources for general maintenance and automotive repairs from a general perspective only and should be used at your own risk. Information is accurate and true to the best of AutoZone’s knowledge, however, there may be omissions, errors or mistakes.

Be sure to consult your owner’s manual, a repair guide, an AutoZoner at a store near you, or a licensed, professional mechanic for vehicle-specific repair information. Refer to the service manual for specific diagnostic, repair and tool information for your particular vehicle. Always chock your wheels prior to lifting a vehicle. Always disconnect the negative battery cable before servicing an electrical application on the vehicle to protect its electrical circuits in the event that a wire is accidentally pierced or grounded. Use caution when working with automotive batteries. Sulfuric acid is caustic and can burn clothing and skin or cause blindness. Always wear gloves and safety glasses and other personal protection equipment, and work in a well-ventilated area. Should electrolyte get on your body or clothing, neutralize it immediately with a solution of baking soda and water. Do not wear ties or loose clothing when working on your vehicle.

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