Having a good understanding of the different types of car brakes and how they work is important for all drivers. Knowing what system your vehicle has can help you maintain it properly, troubleshoot issues, and make informed decisions when repairs are needed. In this guide, we’ll cover the 4 primary brake types found in passenger vehicles and what sets them apart.
1. Disc brakes are the most common type of brake today and use brake pads that squeeze a rotor connected to the wheel. They provide strong stopping power.
2. Drum brakes use curved brake shoes that press against the inside of a brake drum attached to the wheel. They are simpler and cheaper than discs.
3. Parking brakes use a cable system to mechanically activate the brakes and hold the car when parked. They provide emergency stopping if hydraulics fail.
4. Anti-lock braking systems (ABS) pulse the brakes many times per second to prevent wheel lockup and maintain steering control during hard braking.
5. Rotors, drums, brake pads, and shoes are wear items that require periodic inspection and replacement.
6. Noises like squealing or grinding indicate worn brake components needing service.
7. Understanding your vehicle’s brake system allows you to maintain it properly for safety and performance.
Disc brakes are the most common type of brake found on modern cars and light trucks. As the name implies, the key component of a disc brake system is a disc or rotor that is connected to the wheel hub and rotates along with the wheel.
How Disc Brakes Work
When the brakes are applied, hydraulic pressure from the master cylinder actuates a caliper containing brake pads on each side of the rotor. The brake pads squeeze against the rotor, creating friction that slows the rotation of the wheels.
- Brake Pads – Friction material mounted in the caliper that squeeze against the rotor. Pads need to be replaced periodically as they wear down.
- Caliper – Houses the brake pads and uses hydraulic pressure to pinch them against the rotor when braking. Calipers slide on guide pins.
- Rotor – A metal disc attached to the wheel hub that rotates with the wheel. Rotors can become warped over time and need resurfacing or replacement.
Types of Disc Brakes:
- Vented – Have vents or slots in the rotor to allow heat to dissipate. Common on front brakes.
- Solid – No vents, making the rotor lighter. Often used on rear brakes.
- Cross Drilled – Have drilled holes in the rotor surface for better heat dissipation and improved braking in wet conditions. An upgrade on some vehicles.
Advantages of Disc Brakes:
- Better stopping power in most conditions
- More resistant to fade during repeated heavy braking
- Self-cleaning action helps sweep away water and debris
- Easier to service brake pads than drum shoes
Disadvantages of Disc Brakes
- Can be more expensive to replace pads and rotors
- No emergency brake on the disc system itself
Drum brakes were once the most common type of car brake, but have been replaced by discs on most modern vehicles. However, many cars still employ rear drum brakes due to their lower cost and adequate performance for the lighter braking done by the rear wheels under normal conditions.
How Drum Brakes Work
Inside each brake drum is a set of curved brake shoes lined with friction material. When the brakes are applied, hydraulic pressure pushes the shoes outward against the inner surface of the drum, creating friction that slows the vehicle.
- Brake Shoes – Curved pads lined with friction material that press against the drum. Require periodic replacement as the lining wears down.
- Brake Drums – The cylindrical metal components attached to the wheel hubs that the shoes press against when braking. Can become out-of-round over time.
- Wheel Cylinder – Contains pistons that push the brake shoes outward when hydraulic pressure is applied. Can leak fluid over time.
Types of Drum Brakes:
- Basic Drum – Single hydraulic wheel cylinder activates both shoes. Common on older vehicles.
- Duo-Servo – Has dual hydraulic cylinders for more even shoe application. Used on newer rear drum brakes.
- Self-Energizing – Helps the shoes spread wider under braking force for more stopping power. Seen on larger rear drum brakes.
Advantages of Drum Brakes:
- Lower replacement part costs compared to discs
- Integrated emergency/parking brake
- Protected from mud and water inside the drum
Disadvantages of Drum Brakes:
- Not as effective in wet conditions due to moisture buildup inside drum
- More prone to brake fade under repeated heavy braking
- Shoes and drums require periodic adjustment to compensate for wear
- Drum/shoes replacement is more labor intensive than pads/rotors
While disc brakes now dominate, drum brakes are still economical and get the job done for the rear brakes of many vehicles.
All vehicles come equipped with a parking or emergency brake system that allows the car to be held stationary when parked, even without the hydraulic service brakes applied.
While specific designs vary, most parking brakes work by mechanically activating the brakes using cables and levers rather than hydraulic pressure.
Common Types of Parking Brakes:
- Foot Pedal – A third pedal in the driver’s footwell. Pressing it pulls a cable running to the rear brakes.
- Hand Lever – A manual lever between the seats, on the console, or near the door. Pulling the lever activates the parking brake cable.
- Electric Button/Switch – An electric switch that trigger’s the vehicle’s electric parking brake system.
How Parking Brakes Work
Regardless of the type, pulling the lever, pressing the pedal, or hitting the switch tensions a steel cable running to hardware that mechanically actuates either the rear disc calipers or drum brake shoes. This friction holds the rear wheels and keeps the car from rolling.
Releasing the parking brake relieves the tension on the cable and releases the brakes. The parking brake system must be periodically adjusted as the cables stretch over time.
Advantages of Parking Brakes:
- Allow confidently parking on inclines without roll away
- Provide emergency stopping if hydraulic brakes lose pressure
- Low maintenance design
While not intended for regular braking, parking brakes are an essential backup that can get you stopped in an emergency.
Anti-Lock Braking Systems (ABS)
ABS is an advanced braking technology that helps prevent wheel lockup under hard braking, allowing the driver to maintain steering control. It’s a safety feature found on most modern vehicles.
How ABS Works
Sensors at each wheel monitor rotational speed. If sensors detect a wheel is about to lock up under hard braking, ABS will rapidly pulse that wheel’s caliper or drum brake to prevent lockup. This pulsing sensation can be felt through the pedal.
Meanwhile, wheels that aren’t locking up will experience normal hydraulic brake pressure. ABS cycles many times per second to maximize braking force without lockup before coming to a complete stop.
Benefits of ABS:
- Allows steering control to be maintained during emergency stops
- Helps prevent skids caused by locked wheels
- Shorter stopping distances on slick surfaces like gravel or snow
- Computerized self-testing for trouble codes
ABS has saved countless lives by giving drivers much greater vehicle control during abrupt braking maneuvers. It’s one of the most important brake technologies to debut in the last 50 years.
Brake System FAQ
Still have questions about types of vehicle brakes and how they work? Here are answers to some frequently asked questions:
What are the main types of car brakes?
The 4 major types are disc brakes, drum brakes, parking brakes, and anti-lock braking systems (ABS). Most vehicles have disc brakes in front and either discs or drums in back.
Are disc or drum brakes better?
Disc brakes have superior performance under hard braking and in wet conditions. But drums still work well for rear brakes at a lower cost.
Can a mix of discs and drums be used?
Yes, having discs up front for most of the stopping power and drums in back is still a common brake setup.
Do all cars have parking brakes?
Yes, all passenger vehicles are required to have a parking brake system to hold the car when parked. It’s usually a mechanical cable system.
What are the benefits of anti-lock brakes?
ABS helps maintain steering control in hard braking situations by preventing the wheels from locking up and skidding.
Do brakes require periodic maintenance?
Yes, brake pads wear over time and need replacement. Rotors and drums may need resurfacing or replacement. Brake fluid should also be flushed every couple years.
What causes brake squealing or grinding noises?
Common causes are worn-out brake pads/shoes, sticking calipers that aren’t retracting, and glazed/warped rotors or drums.
How long should brakes last?
Brake pad and rotor life is heavily dependent on driving habits and conditions. Generally, expect 20,000-70,000 miles between pad changes and up to 100,000 miles for rotors.
The Bottom Line
Understanding disc, drum, parking, and ABS brakes is helpful knowledge for all drivers. Knowing the basics of how your vehicle’s brake system operates allows you to inspect it routinely and make educated repair decisions. Properly maintaining your brakes helps ensure the safety of you, your passengers, and everyone else on the road.