Drum Brakes Vs Disc Brakes: Which is Better?

What are Drum Brakes?

Drum brakes are a type of braking system commonly used in passenger cars and trucks. When the brake is applied, the hydraulic fluid causes the brake shoes to press on a rotating drum attached to the car wheels. The resulting friction causes the vehicle to come to a halt. Drum brakes are generally known for their simplicity, durability, and effectiveness.

 

How do Drum Brakes Work?

Here’s a simple explanation of how drum brakes work.

1. Brake Pedal Pressed: When the driver presses the brake pedal, it activates a master cylinder.

 

2. Hydraulic Pressure: This pushes hydraulic brake fluid through brake lines to the wheel cylinder located in each drum brake assembly.

 

3. Wheel Cylinder Activation: The hydraulic pressure forces the pistons inside the wheel cylinder to move outward.

 

4. Brake Shoes Expand: These outward-moving pistons push the brake shoes against the inner surface of the rotating brake drum, which is attached to the wheel.

 

5. Friction Generated: The contact between the brake shoes and the brake drum generates friction, causing the drum (and thus the wheel) to slow down or stop.

 

6. Return Springs: When the brake pedal is released, return springs pull the brake shoes back to their original position, disengaging them from the drum and allowing the wheel to rotate freely again.

 

Advantages of Drum Brakes

The benefits of drum brakes in cars include the following.

• Low-Cost: Drum brakes cost less because of their simple design and parts. Consequently, the overall price of the vehicle drops.

 

• Durability: They have a longer lifespan due to the larger surface area for wear distribution.

 

• Easy to Use: Engaging the brakes requires less force because of the straightforward design of the drum brakes.

 

• Easy maintenance: Compared to the brake calliper on a disc brake, the wheel cylinder of a drum brake requires less maintenance.

 

Disadvantages of Drum Brakes

The following are some of the disadvantages of drum brakes.

• Reduced Braking Efficiency: Although drum brakes generally have better braking than disc drakes at lower speeds, at higher speeds, they are less effective.

 

• Heat Buildup: A drum brake's enclosed design can lead to greater heat build-up. This can reduce braking performance during continuous or heavy braking.

 

• Moisture Sensitivity: Drum brakes' enclosed design makes them more prone to moisture and water build-up, which can reduce braking performance.

 

• Reduced Cooling: The drum design provides less exposure to airflow, resulting in poorer heat reduction as compared to disc brakes.

 

• Heavier Design: Drum brakes tend to be heavier than disc brakes, which can impact vehicle handling and fuel efficiency.

 

What are Disc Brakes?

Disc brakes are a type of braking system commonly used in modern vehicles. They are known for their efficiency and superior performance. The key components of a disc brake include brake pads, callipers, and hydraulic fluid. Nonetheless, it slows down a vehicle using the same frictional principle as a drum brake.

 

How do Disk Brakes Work?

Here is a simple breakdown of how disc brakes work.

1. Brake Pedal Pressed: When the driver presses the brake pedal, it activates the master cylinder, which is connected to the brake system.

 

2. Hydraulic Pressure: The master cylinder generates hydraulic pressure, which is then transmitted through the brake lines to the brake callipers.

 

3. Caliper Activation: The brake callipers contain pistons that are pushed outward by the hydraulic pressure.

 

4. Brake Pad Engagement: As the pistons move, they push the brake pads against the rotating brake disc on both sides.

 

5. Friction Generation: The friction created between the brake pads and the spinning disc causes the disc to slow down or stop rotating. This, in turn, slows down or stops the wheel.

 

6. Heat Dissipation: The open design of disc brakes allows for efficient heat reduction. Thus helping to maintain consistent braking performance even under heavy or prolonged use.

 

7. Parking Brake: In some disc brake systems, the parking brake mechanism may be integrated into the calliper assembly. Thus providing a separate means of braking the vehicle when parked.

 

Advantages of Disc Brakes

The following are the advantages of Disc Brakes.

• Improved Braking Performance: Disc brakes generally provide better braking power and responsiveness compared to drum brakes, especially at higher speeds.

 

• Faster Cooling: The open design of disc brakes allows for quicker cooling of the braking components, improving overall braking efficiency.

 

• Compact Design: Disc brake assemblies are generally more compact and take up less space within the wheel well.

 

• Improved Wet Weather Performance: Disc brakes are less affected by water and debris buildup compared to drum brakes. Thus, maintaining better braking performance in wet conditions.

 

• Widespread Adoption: Disc brakes have become the industry standard for modern vehicles, particularly on the front wheels.

 

Disadvantages of Disc Brakes

The following are some of the disadvantages of disc brakes.

• Costlier: Disc brakes typically cost more to produce and repair than drum brakes.

 

• More Wear: The disc brakes' exposed design can lead to faster wear of the brake pads, requiring more frequent replacements.

 

• Complexity: Disc brake systems can be more complex and may require more specialised tools and knowledge for maintenance and repair.

 

• Less Effective Parking Brake: The parking brake mechanisms in disc brake systems can be less effective compared to those in drum brakes.

 

• Potential for Warping: The brake rotors can get overheated, leading to issues like vibration and reduced braking efficiency.

 

• Weight: High-performance disc brake systems with larger rotors can add weight to the vehicle.

 

• Hydraulic Issues: Leaks in the hydraulic system can cause a loss of braking power. However, this is true of drum brakes as well.

 

Difference Between Disc Brake and Drum Brake

The below table outlines some of the key differences between disc and drum brakes.

Characteristic	Disc Brakes	Drum Brakes
Braking Mechanism	Brake pads clamp onto a rotating disc (rotor)	Brake shoes expand outwards to press against the inner surface of a rotating drum
Braking Performance	Superior braking power, especially at high speeds	Adequate braking power, but less effective at high speeds
Heat Dissipation	Efficient heat dissipation due to open design	Less effective heat dissipation due to the enclosed design
Maintenance	Simpler maintenance, such as pad replacement	More complex maintenance, including drum resurfacing or replacement
Exposure to water and debris	More exposed to environmental factors like water and debris	Less exposed to environmental factors but more susceptible to moisture buildup
Parking Brake Mechanism	A separate parking brake system required	Integrated parking brake mechanism
Cost	Generally more expensive	Generally less expensive
Weight	Lighter weight components	Heavier weight components
Common Application	Front wheels of most modern vehicles	The rear wheels of many vehicles, especially in budget-oriented models

Which Is Better–Disc Brake or Drum Brake?

The choice between a disc and drum brake depends on your personal preferences and the vehicle model. To recap, a disc brake provides better braking performance, heat elimination, and consistency. On the other hand, drum brakes are more cost-effective, simpler to install, and offer better braking at low speeds. That being said, many modern cars combine both brakes—disc brakes in the front and drum brakes in the back. To sum up, the best choice depends on the specific requirements and intended use of the vehicle.

 

Road Safety and Insurance

While an effective braking system can increase safety on the road, it cannot eliminate the possibility of accidents altogether. Fortunately, Car Insurance offers financial protection against accident-related expenses like damages to your car and injuries or death to a third party and/or damage to their property. If you are looking for a reliable insurance provider for your car, we suggest getting insured with Shriram General Insurance. Our Comprehensive Car Policy offers extensive coverage for four-wheelers, with the option to increase coverage using Add-Ons.

 

FAQs

1. What are the main differences between drum brakes and disc brakes?

Drum brakes use an enclosed drum mechanism, while disc brakes use exposed brake discs and callipers. Also, compared to drum brakes, disc brakes generally offer better braking performance, heat dissipation, and consistency.

 

2. Which type of brake is more effective?

Disc brakes are generally considered the better option between disc and drum brakes.   They provide stronger and more reliable braking power, especially at higher speeds and under heavy use.

 

3. Do drum brakes have any advantages over disc brakes?

Yes, drum brakes are more affordable and provide good braking force at lower speeds. They are often used on vehicles' rear wheels, complementing the disc brakes in front.

 

4. Can drum brakes be upgraded to disc brakes?

Yes, in some cases, it is possible to upgrade from drum brakes to disc brakes. However, the car model has to be compatible with disc brake installation. Alternatively, you may be able to install a disc brake in a car by making significant modifications to the braking system and suspension.