Everything You Need To Know About Brake Pads

Your Guide To Understanding Brake Pads

With great engine power, comes great braking responsibility! As our engines get progressively more powerful, it becomes imperative to have sufficiently powerful brakes that can help you stop your car safely. This is why most modern cars since the early 1970s have disc brakes on at least 2 wheels of the vehicle. Disc brakes have many advantages over drum brake systems making them common in modern automobiles. The most important part of the disc brake system is the brake pads. This article aims to give you an insight into everything brake pad related so you can appreciate the brake system in your vehicle and make a better buying decision the next time you are shopping for brake pads. 

In this article:

What Are Brake Pads?

Brake pads are part of a disc brake system and are essentially a flat piece of metal with friction lining on one side. The friction lining is responsible for creating friction between the pad and the rotor which helps slow down and stop the wheels. 

How Do Brake Pads Work?

The Brakes in your cars are resilient and hardworking systems that work towards countering the forward energy of the car and bringing you to a stop, safely. Brake pads are an important part of the modern disc brake system. Brake pads functioning is fairly simple to understand - they clamp the brake rotors or discs which are mounted to the rotating wheels, and this stops the wheel and ultimately the car. The disc comes to a stop due to the effect of friction between the brake pad surface and the brake rotor. Brake pads are integrated into the brake callipers that are part of a hydraulic system that transfers the brake pedal movement to the brake pads. Here’s a brief on how the disc brake system works:
  • When the brake pedal is depressed, the brake master cylinder is actuated usually through the brake power booster that pressurizes brake fluid. 

  • This hydraulic pressure within the brake lines is transferred to the brake calliper which houses a piston. The piston expands within the calliper. 

  • The brake pads are connected to the pistons either directly or indirectly depending on the type of calliper assembly. There are two pads surrounding the brake rotor, clamping on it from both ends. 

  • As the piston moves, the brake pads are forced against the brake rotors, 

  • The friction between the brake pad and rotor slows down the wheel and brings the car to a stop.

  • The harder you push the pedal, the more force is applied at the brake pads, and greater is the friction. This increases the rate at which the vehicle slows down but also generates more heat. However, the ABS system plays an important role in modulating the brake force to maximize stability and safety while braking. Learn more about the ABS system's functioning in this article.

Friction is detrimental for any mechanical system, however, effective use can help us in many ways but at a premium price. What that means is although we are able to use the force of friction to stop the vehicle, we need to compromise or compensate by sacrificing brake pads in order to effectively brake every time. When a vehicle is brought to a stop all the energy of the moving vehicle is almost completely converted into heat energy. This heat energy is felt at the rotor and the brake pads and can reach upwards of 450℃. This amount of heat is able to melt most materials and so brake pads need to be made of hardwearing elements that can withstand heavy stresses and temperatures and also last long. This is why there are many types of brake pads materials used today like metallic, ceramic and organic.

Which Brake Pads Material Should I Choose?

Being able to stop your automobile quickly is more essential than acceleration. That's why choosing the right brake pad for your vehicle is important. There are various types of brake pads materials used, mainly organic, ceramic and metallic. If you want to know which brake pad is best suited for your vehicle then refer to the “Which Brake Pads Is Right For My Vehicle” section in our brake pad buying guide.

How To Choose The Right Brake Pads?

What Are The Signs Of Worn-Out Brake Pads?

The brake pads are essential to every disc brake system and their failure can indicate many different signs before the vehicle is at risk of complete brake disability. Always make sure to take immediate action when it comes to brake system failure in your vehicle. Here are a few most significant symptoms experienced when brake pads fail:

  1. Reduced Braking Effect: The most prominent sign indicating bad brake pads is the slow or reduced braking effect. The brake pads are responsible for stopping the rotor and if the brake pads are worn out then you can expect reduced braking effect and increased braking distance. 

  2. Soft Or Spongy Brake Pedal: Uneven or severely worn-out brake pads have the tendency to cause a spongy response on brake pedal operation. Severely worn-out brake pads will also require you to press the brake pedal harder and further to effectively brake which is indicated by a soft brake pedal. 

  3. Annoying Sounds from the Brakes: Some brake pads come with a brake pad wear indicator in which once the brake pads are completely worn out, a metal disc comes in contact with the rotor causing a squealing noise due to metal-on-metal contact. Grinding noise is another sound that may emanate from the brakes when there is the presence of dirt, gravel or rocks on the calliper or disc causing grinding noises when brake pads come in contact. 

  4. Vibrations While Braking: If the brake pedal, steering wheel or tires seem to wobble or vibrate when the brakes are applied then there may be a problem with the brake pads or rotors. The brake pads can wear unevenly or chunks of brake pad material can break off or get deposited on the rotor surface permanently and when the brakes are applied this uneven surface of the rotor comes in contact with the brake pads causing vibrations. This can also be caused by warped rotors. 

  5. Vehicle Pulling to One Side: The brakes are applied with even pressures to both corresponding wheels and the distribution of the braking force is equivalent. When the vehicle pulls to one side or causes uneven braking, it indicates that the brake pads may be worn out unevenly in adjacent wheels.

  6. Pungent Or Burning Smells: Burning or pungent smells may be a result of overuse of the brakes which push them to their limits causing extreme heat in the brake pads. This can be particularly dangerous since avoiding to stop and allowing time to vent and cool off the brakes can cause the brake fluid to heat up to its boiling point and result in complete brake failure. 

  7. Brake Warning Light: If the brakes are worn out, a brake light is illuminated in the dashboard indicating potential brake failure. Previously mentioned squealing noise is due to a mechanical brake wear indicator. Electronic brake wear indicators sense the amount of brake material left and send a signal which alerts the driver to the brake pad condition. Some less advanced systems simply show a warning light when the brake pads need replacement. There may also be an electronic noise generated if the brake pads are worn completely and urgently need to be replaced.  

In case you are experiencing one or more of the above symptoms then take a look at your brake pads and have them replaced immediately. 

How Often Should My Brake Pads Be Inspected?

General wisdom says to have your brakes (including your brake pads) should be inspected every 5 months or 5,000 miles, but your manufacturer guidelines would provide you better guidance for your particular automobile. If you are hearing noises like grinding, squeaking, or squealing, your steering wheel feels shaky, or there is an illumination of brake warning light, then you should get it inspected. 

If you are willing to know more about how can you inspect your brake pads, then make sure you visit our “How To Inspect Your Brake Pads?” section. 

How To Replace Brake Pads?

The replacement process for brake pads can be a little complicated for a newbie or someone with less experience working on cars. However, with the right set of tools and a detailed guide you can try changing your brake pads. Here is a step-by-step guide on replacing brake pads yourself. Make sure you refer to your service manual for vehicle-specific replacement procedures.

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John Framigllia
Technical Writer
Our technical writer is known for simplifying automotive parts and services. Intuitive with various vehicles and manufacturers, he knows how to simplify complicated problems.