Types of Car Brakes and Brake Pads: How They Work, Their Uses and Their History

A powerful engine makes a car fast, but a properly engineered braking system makes that performance usable. From traditional drum brakes and cast-iron discs to carbon-ceramic rotors, racing pads and regenerative braking, every system has been designed for a particular operating environment. This guide explains the main types of car brakes, brake discs, calipers and brake-pad compounds, including their advantages, disadvantages and correct applications.

What Does a Braking System Do?

A vehicle’s brakes convert kinetic energy into heat. When the driver presses the brake pedal, hydraulic pressure is generated and transmitted to the wheel brakes. The resulting friction slows the rotating wheels and, through the tyres, reduces the speed of the vehicle.

This last point is important: the brakes do not stop the car directly—the tyres transfer the braking force to the road. A larger brake system can improve heat capacity, consistency, pedal feel and resistance to fade, but it cannot overcome the available grip between the tyre and the road.

Modern braking systems may also incorporate a vacuum or electronic brake booster, ABS, electronic brake-force distribution, stability control, automatic emergency braking and regenerative braking. These are control or assistance systems rather than separate types of wheel brake.

A Brief History of Automotive Brakes

The earliest cars used mechanically operated blocks or bands acting on the wheels or drivetrain. These systems were acceptable at very low speeds but quickly became inadequate as vehicles became heavier and faster.

Drum and disc brake concepts both emerged around the beginning of the twentieth century. Frederick William Lanchester patented an early caliper-type automotive disc brake in 1902, while an internal expanding drum-brake design associated with Louis Renault also appeared during the same period. Early disc systems were limited by the friction materials and metallurgy available at the time, allowing drum brakes to dominate road-car production for several decades.

Disc brakes became far more important during the 1950s. Jaguar and Dunlop developed disc brakes for the Jaguar C-Type, achieving the first victory for a disc-braked car at Reims in 1952. The disc-braked C-Type then won the 24 Hours of Le Mans in 1953, demonstrating the system’s consistency and heat resistance under endurance-racing conditions.

Electronic control became the next major development. Bosch began intensive ABS development in 1969 and introduced its first production-ready electronically controlled ABS system in 1978. ABS helps prevent the wheels from locking under heavy braking, preserving steering control and vehicle stability.

Today, braking systems combine hydraulic, mechanical and electronic technologies. Hybrid and electric vehicles also recover part of their kinetic energy through regenerative braking, while increasingly advanced vehicles use electro-hydraulic and brake-by-wire architectures.

Disc Brakes

Disc brakes are now the main braking system used on the front axle of modern passenger cars and on all four wheels of most performance vehicles.

A disc-brake system consists of a rotor, commonly called the brake disc, a caliper and a pair of brake pads. Hydraulic pressure moves the caliper pistons, pressing the pads against both sides of the rotating disc.

The friction between the pads and the disc converts the vehicle’s movement into heat. That heat must then be absorbed and released without allowing the pad, disc, caliper or brake fluid to exceed its intended operating range.

Advantages of Disc Brakes

Disc brakes are exposed to airflow and generally dissipate heat more efficiently than enclosed drum brakes. They also recover more quickly after driving through water and provide consistent braking during repeated high-energy stops.

Their open construction makes inspection and pad replacement relatively straightforward. This is one reason disc brakes are preferred for performance cars, heavy vehicles and motorsport.

Disadvantages of Disc Brakes

Disc systems can cost more to manufacture than basic drum brakes. Exposed discs are also susceptible to surface corrosion, and large performance systems may produce more brake dust, noise and replacement cost.

A badly matched combination of pad and disc can cause squeal, judder, accelerated wear, cracking or inconsistent pedal feel.

Types of Brake Discs

Solid Brake Discs

A solid disc is manufactured as a single friction ring without internal cooling channels.

Solid discs are relatively light, inexpensive and suitable for rear axles or lower-powered vehicles where braking temperatures remain moderate. Their main limitation is reduced thermal capacity compared with a ventilated disc of similar dimensions.

Ventilated Brake Discs

A ventilated disc consists of two friction faces separated by internal vanes. As the disc rotates, the vanes move air through the rotor, improving heat dissipation.

Ventilated discs are commonly used on front axles and high-performance vehicles because the front brakes normally handle the greatest proportion of braking energy.

Ventilation should not be confused with drilling. A ventilated disc has internal air passages, while a drilled disc has holes passing through its friction surface.

Plain Brake Discs

A plain or smooth disc has an uninterrupted braking surface. A high-quality plain disc is often the best option for normal road use because it offers good pad contact, low noise and predictable wear.

Plain discs should not automatically be considered inferior to drilled or slotted designs. Material quality, vane design, disc mass, pad compatibility and cooling airflow can be more important than the appearance of the braking surface.

Drilled Brake Discs

Drilled discs contain holes in the friction ring. The holes can help clear water, gases and surface contamination while improving initial response under certain conditions.

They are popular on road-going performance and luxury cars because of their appearance and responsive pedal feel. However, each hole creates an area of increased local stress. A properly engineered drilled disc can be reliable, but lower-quality or incorrectly drilled discs may develop heat cracks under repeated circuit use.

Brembo notes that drilled discs can provide strong heat dissipation, while slotted discs generally offer greater mechanical resistance to cracking under extreme competition conditions.

Slotted Brake Discs

Slotted discs have machined channels across the braking surface. The slots help clean the pad face, remove water and gases and maintain a fresh friction surface.

They are commonly used in performance and track applications. The trade-offs can include increased pad wear, additional noise and a more aggressive pedal sensation.

For serious track use, a properly engineered slotted disc is often preferred to an aftermarket disc that has simply been drilled without the necessary material, stress analysis or heat treatment.

Grooved and J-Hook Discs

J-hook and curved-groove patterns are variations of the slotted-disc principle. They are designed to improve initial bite and clean the pad surface while managing stress concentration and noise.

The pattern alone does not determine performance. The disc material, thickness, ventilation, manufacturing process and pad combination remain critical.

One-Piece and Two-Piece Discs

A one-piece disc has the friction ring and mounting section manufactured as one component, normally from cast iron.

A two-piece disc uses a separate friction ring connected to a central bell, often made from aluminium. This arrangement can reduce unsprung mass and allow more controlled thermal expansion of the friction ring.

Floating two-piece discs permit a small amount of controlled movement between the ring and bell, reducing thermal stress and helping the disc remain correctly aligned under high temperatures. Brembo uses this principle in performance systems to manage heat while reducing weight.

Carbon-Ceramic Brakes

Carbon-ceramic brake discs are used on many high-performance road cars and supercars.

A carbon-ceramic disc is normally manufactured from a composite containing carbon fibres, silicon carbide and silicon. It is not simply a conventional cast-iron disc covered in ceramic paint.

Carbon-ceramic discs offer excellent resistance to corrosion and high temperatures while significantly reducing rotating and unsprung mass. They can also provide long service life when used correctly on the road. Brembo describes the material as a carbon-fibre-reinforced silicon-carbide composite engineered for mechanical strength and high-temperature stability.

Their main disadvantage is cost. The discs can also be damaged by impact, incorrect handling or unsuitable pad compounds. Replacement prices are considerably higher than for cast-iron systems.

A road-car carbon-ceramic system should not be confused with a carbon-carbon racing brake. Carbon-carbon discs are used in specialised motorsport environments and are engineered around very different operating conditions.

Drum Brakes

A drum brake uses curved brake shoes mounted inside a rotating drum. When the brake pedal is pressed, a hydraulic wheel cylinder pushes the shoes outwards against the internal surface of the drum.

Some drum designs create a self-energising or servo effect. The rotation of the drum helps pull a leading shoe into contact, reducing the hydraulic pressure required to generate braking force.

Advantages of Drum Brakes

Drum brakes are compact, relatively inexpensive and well protected from external contamination. They can also integrate an effective mechanical parking-brake mechanism.

For this reason, drum brakes remain suitable for the rear axle of some smaller cars, commercial vehicles and electric vehicles where regenerative braking reduces the workload placed on the rear friction brakes.

Disadvantages of Drum Brakes

The enclosed design retains heat. During repeated heavy braking, rising temperature can reduce friction and cause brake fade.

Drum brakes can also be more complicated to inspect and service because of their internal springs, adjusters, retainers and wheel cylinders.

They remain effective for appropriate applications, but they are generally less suitable than ventilated disc brakes for sustained high-performance use.

Fixed and Floating Brake Calipers

Floating or Sliding Calipers

A floating caliper normally has one or more pistons on the inboard side of the disc. When hydraulic pressure is applied, the piston pushes the inner pad against the disc while the caliper body slides across its guide pins, pulling the outer pad into contact.

Floating calipers are compact, cost-effective and widely used on road cars.

The guide pins and sliding surfaces must remain clean and correctly lubricated. A seized slider can cause uneven pad wear, overheating and the vehicle pulling during braking.

Fixed Calipers

A fixed caliper is rigidly mounted and normally has pistons on both sides of the disc. The caliper body does not slide.

Fixed calipers can offer improved stiffness, pressure distribution and pedal consistency. They are commonly found on performance vehicles, supercars and racing cars.

However, the number of pistons does not automatically determine braking performance. Piston area, caliper stiffness, master-cylinder sizing, disc diameter, pad area, hydraulic balance and tyre grip must all be considered as one system.

What Are Brake Pads Made From?

A brake pad consists of a steel backing plate with a friction compound bonded or mechanically secured to it. The formulation may contain fibres, metals, abrasives, lubricants, fillers and binding resins.

There is no single best brake-pad material. Continental states that its ATE range alone uses more than 150 formulations because the friction material must be matched to the requirements of the individual vehicle.

The main brake-pad categories are organic or NAO, low-metallic, semi-metallic, ceramic-composite and specialist racing compounds.

Organic and NAO Brake Pads

NAO means non-asbestos organic. These pads use organic fibres and other reinforcing materials held together by resin.

They are generally designed to provide quiet operation, progressive pedal feel and relatively low disc wear. This makes them suitable for normal passenger cars and urban driving.

Their limitations can include greater wear, increased dust and reduced resistance to sustained high temperatures compared with more aggressive metallic or racing formulations.

The exact behaviour depends on the compound. “Organic” should not automatically be interpreted as low quality.

Low-Metallic Brake Pads

Low-metallic pads are based on an organic formulation with a controlled quantity of metallic material added to improve heat transfer, friction and pedal response.

They are common on European vehicles and can provide strong initial bite and consistent road performance.

Possible disadvantages include increased brake dust, noise and disc wear compared with a comfort-oriented ceramic compound.

Semi-Metallic Brake Pads

Semi-metallic pads contain a greater proportion of metallic fibres or particles.

They generally offer good heat resistance, strong bite and consistent friction under demanding conditions. They are often used on heavier vehicles, powerful road cars and performance applications.

They can produce more noise and dark brake dust, and some compounds may be more abrasive towards the discs.

The term “semi-metallic” covers a large range of formulations. Two pads carrying the same general description may behave very differently.

Ceramic Brake Pads

Ceramic-composite pads use ceramic fibres and other materials within the friction compound.

Road-oriented ceramic pads are often developed to reduce visible dust and noise while providing stable everyday braking. They can be a good option for luxury vehicles where cleanliness and refinement are important.

However, “ceramic pad” does not mean “racing pad,” and it does not mean that the pad is automatically suitable for a carbon-ceramic disc.

A ceramic-composite pad for an iron road disc and a pad engineered for a carbon-ceramic braking system are different products. The pad must always be approved for the specific disc material and application.

Sintered Metallic Pads

Sintered pads are produced by compressing and heating metallic powders until they bond together.

They are particularly common in motorcycles and specialist competition applications because they can provide strong friction, durability and resistance to demanding conditions.

They may generate more noise and disc wear, and they should only be used with compatible disc materials.

Racing Brake Pads

A racing pad is not defined by one single material. Racing compounds are developed around specific requirements such as temperature range, initial bite, modulation, fade resistance, wear rate and disc compatibility.

A sprint-racing pad may prioritise high bite and maximum friction. An endurance compound may sacrifice some initial aggression to improve pad and disc life. A rally pad may need useful friction from relatively low temperatures while still tolerating repeated high-energy stops.

AP Racing specifically warns that friction coefficient is not an absolute value. It changes with temperature, speed, hydraulic pressure and braking energy. Effective temperature ranges should therefore be treated as compound-specific guidance rather than a universal rule.

This is why statements such as “all racing pads work from 300°C to 800°C” are inaccurate. The correct operating range must come from the technical data for the exact compound.

Road Pads Versus Track Pads

A road pad must work from cold, operate quietly, produce manageable dust and remain predictable during rain, traffic and emergency braking.

A track pad must survive repeated high-energy stops without losing friction. It may produce noise, dust and increased disc wear, and some compounds may not provide their intended performance when cold.

A road-performance pad can be an effective compromise for fast road driving and occasional light track use. However, a genuine race compound is not automatically an upgrade for a road car.

The correct pad depends on the vehicle weight, tyre, brake cooling, disc material, circuit, driver, session length and expected temperature.

What Is Brake Fade?

Brake fade is a reduction in braking performance during repeated or prolonged use.

Pad Fade

Pad fade occurs when excessive temperature changes the friction behaviour of the pad. The driver may press the pedal with normal firmness but receive less braking force.

Brake-Fluid Fade

Brake-fluid fade occurs when the fluid becomes hot enough to boil. Vapour is compressible, so the pedal can become long or spongy.

This is different from pad fade and cannot be corrected simply by fitting a more aggressive pad.

Green Fade

New pads can release gases as their resins experience their first high-temperature cycles. Incorrectly subjecting new pads to extreme heat can produce temporary loss of friction or damage the compound.

Correct bedding reduces this risk and prepares the disc and pad surfaces to work together.

Why Brake-Pad Bedding Matters

Bedding creates stable contact between the pad and disc and establishes the correct friction surface or transfer layer.

There is no single bedding procedure suitable for every pad. AP Racing advises following the instructions provided by the friction-material manufacturer because racing and road compounds require different heat cycles.

Incorrect bedding can cause uneven pad deposits, vibration, judder, reduced bite and localised overheating.

A common mistake is to come to a complete stop with extremely hot brakes and keep the pedal firmly applied. This can leave an uneven deposit on the disc beneath the stationary pad.

Regenerative Braking

Hybrid and electric vehicles can use the electric motor as a generator during deceleration. Instead of converting all kinetic energy into heat at the friction brakes, part of the energy is converted into electricity and returned to the battery.

Regenerative braking reduces energy consumption and can extend driving range. Bosch describes regenerative systems as combining generator braking with the conventional foundation brakes.

Regeneration does not eliminate the need for discs, pads and hydraulic brakes. Friction braking is still required during emergency stops, at very low speeds, when the battery cannot accept more energy and whenever the requested deceleration exceeds the available regenerative capacity.

Because friction brakes may be used less frequently on an electric vehicle, corrosion and restricted caliper movement can become significant maintenance concerns.

Brake-by-Wire

In a brake-by-wire architecture, the driver’s request is measured electronically rather than being transmitted only through a conventional mechanical pedal connection.

Electronic actuators then generate and control hydraulic pressure. Redundant circuits and control systems are required because braking is a safety-critical function.

Brake-by-wire is an actuation and control architecture, not a replacement for the disc or drum at the wheel. Bosch’s current system uses redundant hydraulic actuators and electronic signal paths to control the four wheel brakes.

Parking Brakes

A parking brake is designed to hold the vehicle stationary rather than repeatedly slow it from speed.

It may use a mechanical cable, an electric motor acting on the rear caliper, or a separate small drum brake located inside the centre of the rear disc. This last arrangement is commonly called a drum-in-hat parking brake.

An electronic parking brake is not the same as brake-by-wire, although both use electronic control.

Choosing the Correct Brake Pad

For a normal road car, the safest choice is a high-quality pad matched to the original equipment specification.

For a high-performance road car, the pad should provide strong cold response, predictable modulation and improved temperature resistance without excessive noise or disc wear.

For occasional track use, a genuine road-and-track compound may be appropriate, although the vehicle’s weight and braking energy must be considered carefully.

For regular track use or competition, pad choice should be based on measured temperatures, driver feedback, wear data, circuit demands and compatibility with the disc.

Selecting pads by advertising claims or maximum temperature alone is poor practice.

Do Bigger Brakes Always Stop a Car Faster?

Not necessarily.

During one emergency stop, braking distance is often limited mainly by tyre grip, road surface, suspension control and ABS calibration.

A larger brake system becomes valuable when the brakes are used repeatedly. Increased disc diameter and mass can improve braking torque and thermal capacity, while a stiffer caliper can improve pedal consistency and modulation.

A correctly engineered upgrade helps the vehicle repeat the same braking performance without overheating. An oversized system that is badly balanced, incorrectly installed or paired with unsuitable pads can make the car worse rather than better.

Brake Maintenance

Brake pads should be inspected for remaining friction material, uneven wear, cracking, contamination and overheating.

Discs should be checked for minimum thickness, excessive run-out, heat cracks, corrosion and uneven deposits.

Caliper sliders, pistons, seals and dust boots must operate correctly. Flexible hoses should be inspected for deterioration, while brake fluid should be changed according to the vehicle and fluid manufacturer’s requirements.

Track use, mountain driving, towing, increased vehicle power and repeated high-speed braking may justify shorter inspection and service intervals.

Never use a universal minimum pad or disc thickness. The correct wear limit must come from the vehicle, caliper or disc manufacturer.

Final Thoughts

The best braking system is not necessarily the largest, most expensive or most aggressive.

Drum brakes remain effective for low-load rear-axle and parking-brake applications. Conventional iron disc brakes provide excellent performance for most vehicles. Carbon-ceramic systems reduce weight and tolerate demanding temperatures, while racing brakes are engineered around very specific operating conditions.

Brake pads must also be chosen as part of the complete system. Friction level, temperature range, pedal feel, noise, dust, wear, disc material, tyres and vehicle use all matter.

For road, performance and motorsport applications, the correct approach is to select and calibrate the entire braking system—not simply fit the most aggressive pad available.