Brake pads, also known as brake bands, play a vital role in the disc brake system of vehicles. They feature strong steel backing plates with specially formulated friction material securely attached to one side. When the driver steps on the brake pedal, the advanced hydraulic system springs into action, prompting the brake pads to apply precise pressure against the brake rotor or disc. This process creates optimal friction, allowing your vehicle to slow down or come to a smooth and safe stop. The brake pads seamlessly integrate with the brake caliper on each wheel, working in harmony with the brake disc to establish a highly efficient and responsive braking system.

 

Function

Brake pads have essential functions in generating friction, dissipating heat, providing smooth and controlled braking, reducing noise, ensuring wear resistance, delivering compatibility and performance, as well as prioritizing safety, reliability, and environmental considerations.

 

  • Friction Generation: Brake pads create friction against the brake rotor or disc when the brakes are applied. This friction converts the moving vehicle's kinetic energy into thermal energy, ultimately slowing down or stopping the vehicle.

  • Heat Dissipation: The heat produced during braking is efficiently dissipated by brake pads. The materials and design of the brake pad aid in dissipating the heat produced by the friction between the brake pad and rotor, preventing overheating and maintaining ideal braking performance.

  • Smooth Braking: Brake pads have a key function in providing smooth and controlled braking that is designed to deliver consistent and progressive friction, allowing the driver to modulate the braking force according to the desired deceleration.

  • Noise Reduction: The noise generated by braking is reduced by the design of brake pads. To lessen or eliminate brake squeals, vibration, and other unwelcome noises that may occur while braking, manufacturers use a variety of techniques including chamfers, slots, shims, and noise-dampening materials.

  • Wear Resistance: Brake pads are built to withstand the high friction and heat generated during braking while maintaining their effectiveness over an extended period. They are formulated with materials that offer good wear resistance, minimizing the need for frequent replacement.

  • Compatibility and Performance: Brake pads are designed to be compatible with specific brake systems and vehicle models. They are engineered to provide optimal performance and braking efficiency, considering factors such as vehicle weight, driving conditions, and temperature ranges.

 

Components

Brake pads have key components for friction, heat dissipation, and vibration reduction. While designs vary, it's important to choose recommended pads.Original equipment parts can be pricey,but aftermarket options offer comparable quality and better prices. This article helps you choose the right brake pads for your needs.

  • Friction Materials: Friction materials are essential components of brake pads, substances used to create friction between surfaces for controlled motion. They can be made from various materials like ceramics, metals, and fibers, playing a crucial role in safe braking and power transfer in transportation.

  • Backing Plates: Backing plates are metal components in the brake pads that provide a solid foundation. In disc brakes, they form the friction surface within the brake shoes. Backing plates securely attach brake components, protect against heat, and are vital for functionality and safety in vehicles.
     

  • Shims: Shims are the main components of brake pads, thin pads placed between the brake pad and caliper to reduce noise and absorb vibrations. They act as a barrier, minimizing heat transfer and improving braking performance. Shims are commonly used in newer cars and can be made of various materials. Replacing shims with brake pad replacement is recommended for continued effectiveness.

  • Adhesive: An adhesive used in brake pads is a bonding agent that securely attaches the friction material to the backing plate. It forms a strong and durable bond capable of withstanding the high forces and temperatures generated during braking. By ensuring a reliable attachment, the adhesive enables consistent and effective braking performance.

 

  • Wear Indicator: A wear indicator, also called a squealer, is a part of brake pads that produces a squeaking sound when the pads are worn out. It alerts drivers that the brake pads need to be replaced by making contact with the metal rotor. This helps maintain safe braking and is used in various vehicles and industrial applications.




Types

Here are some commonly used types of brake pads – semi-metallic, ceramic, low-metallic (NAO), and non-asbestos organic.

 

  • Semi-Metallic: Semi-metallic brake pads blend metallic fibers like steel or copper with organic materials for increased braking performance and heat dissipation. They are popular for being budget-friendly, efficient, and suitable for high-performance vehicles. While they may produce more noise, brake dust, and cause slightly faster rotor wear, their advantages make them ideal for demanding situations.
  • Ceramic: Ceramic brake pads provide excellent braking, generate minimal noise and minimal dust, and absorb heat generated from even the harshest stops. They tend to be more expensive than other brake pad types, but they stand out as the cleanest and quietest option among various materials. Also, they have a longer lifespan compared to semi-metallic pads.
  • Low-Metallic (NAO): Low-metallic brake pads consist of a small amount of metal, typically steel or copper. They certainly offer advantages in heat transfer and braking performance. However, they are known for being noisy and producing a significant amount of brake dust when compared to ceramic pads.
  • Non-Asbestos Organic: Non-asbestos organic brake pads, generally made from organic materials such as fiber, glass, rubber, and Kevlar, offer a quiet braking experience. However, they have a tendency to wear faster and generate significant brake dust. They are best suited for everyday road driving and rather than frequent or intense braking situations.

 

Failures of Brake Pad

Brake pads are able to experience various failures that affect their functionality and reliability. These failures range from wear-related problems to issues caused by external factors. Understanding common brake pad failures is crucial for maintaining a vehicle's braking system's safety and performance. Some factors like these can cause poor functioning:

  1. Uneven Brake pads: Brake pads can of course be worn off because of aging, but sometimes one can be more worn out than the others. If a component called brake calipers malfunction, the balance between one and another brake pad can collapse and thus make it wear off faster. When it happens, the imbalance force sent to the brake pads might reduce brake performance.

  2. Overheating: When you descend from a steep hill or haul an overweight load, the brake pads will be extremely stressed. That can cause excessive heat and thus cause brakes to wear away, and in the worst scenario, even create glaze over the surface and make the performance fall.

  3. Surface Glazing: Extension from the above, when the brakes get overheated, the friction material can get smoothen and hardened into the level of creating a thin layer over the brake pad. The friction required can be lost, and the effectiveness of the part will drop.

 

Symptoms of Failure

  • Noisy Brakes: 
    Noisy brakes are a prevalent indication of brake pad failure. As brake pads wear down, they can accumulate dust, leading to vibrations and squealing when the brakes are applied. It's crucial to address noisy brakes promptly to avoid further damage and ensure safety.

    i) Squeaking Noise(or Squealing Noise:
    These noises can also result from worn pads that have reached the point of contact between the wear sensor and the rotor.

    ii) Grinding Noise: 
    These noises during braking indicate significant wear, potentially resulting in metal-on-metal contact and damage to the rotors.

 

  • Brake Light on:
    If the brake light indicator appears on your dashboard, it indicates either the need for regular brake maintenance or a potential problem with the brakes. This light typically signifies low brake fluid in the master cylinder, possibly due to a leak, or it may indicate that the emergency/parking brake is engaged, especially in older vehicles. Release the parking brake first and check if the warning light disappears. If it persists, there may be an issue with your brakes. Refer to your vehicle owner's manual for more information on dashboard indicators and warnings. The brake light illuminating can be a clear signal of faulty brake pads, prompting the driver to consult a mechanic to confirm the need for replacement.

  • Spongy Brakes:
    Spongy brakes are characterized by a soft or mushy sensation in the brake pedal, indicative of diminished brake system performance. While worn brake pads can be a contributing factor, sponginess is commonly associated with issues such as a faulty brake master cylinder, brake fluid leaks, or the presence of air or moisture within the braking system. Timely inspection and repair of the brake pads are imperative to restore optimal functionality.

 

  • Vibration When Braking
    Vibrations when braking can occur due to issues with brake pads, brake rotors, calipers, or suspension components. Uneven wear of brake pads, warped rotors, or contaminated pads can cause these vibrations. Timely inspection resolving the underlying issue is important for restoring proper braking performance and eliminating vibrations by qualified mechanic inspection.

 

 

Tests

CTR offers a comprehensive range of verification tests for brake pad - chase friction material test and compressibility test.