When it comes to maintaining your car, understanding the brake system is crucial, and knowing the difference between drum brakes and disc brakes can help you make better decisions about your vehicle’s upkeep.
These two styles of brakes might have a few things in common, but they’re quite different in most ways. Learn the key differences, pros and cons of each brake type, and advice on which system might be best for your needs.
Drum Brake vs. Disc Brake
There are several additional components that are involved to ensure the car brakes operate smoothly in different road conditions.
A car accident often happens due to a poor braking system. The more you know about this crucial system, the better you understand your vehicle. So, firstly we have to know how this braking system works.
Friction and heat are the basic principles applied in the braking system. These are generated during braking by reducing the speed.
The major brakes currently available are drum brakes and disc brakes. Both have benefits and drawbacks. Today we are comparing them to see which is the better option for your driving conditions.
So, now let’s discuss both the drum and disc braking system and their function.
Drum Brake
It is an ancient and traditional brake system. It is a drum designed like a component where being used for braking purposes. Inside a drum brake, there is a set of brake shoes.
The brake shoe pushes the drum towards itself when the pedal is pressed and helps reduce vehicle speed. Eventually, the drum brake generates a lot of heat. Due to that heat, the plate may often lose its stopping power, especially in certain braking conditions.
Frequently applying the brakes will lead to increased heat in the braking system. In this condition, the drum brake loses its efficiency due to overheating.
How Do Drum Brakes Work?
- As with disc brakes, pressing the brake pedal generates hydraulic pressure in the master cylinder, which contains brake fluid.
- The pressurized fluid passes through the brake lines, causing — and here’s where the drum differs from disc operation — wheel cylinder pistons to press the brake shoes against the inner surface of the brake drum, generating friction and causing the vehicle to slow.
Drum brakes are often on the rear wheel of new entry-level vehicles. Since most of the braking is handled by the front wheels, using drum brakes in the rear can help keep the price of a new car more affordable.
Parts of a Drum Brake
The following are the main parts of a drum brake:
- Brake plate
- Brake drum
- Wheel cylinder
- Brake shoe
#1. Brake Plate.
The brake plate is a base component. This increases the rigidity of the entire system, supports the housing, and protects it from foreign materials such as dust, dirt, and other road debris.
The brake plate receives torque from the braking action, and therefore the backplate is also known as the torque plate.
#2. Brake Drum.
It is made of a particular type of cast iron that is heat-conductive and wear-resistant. When the brake is applied, the lining pushes against the internal surface of the drum. Hence, the friction goes down, and it stops the rotation of the wheel and axle.
#3. Wheel Cylinder.
The wheel cylinder consists of two pistons that operate the shoes on each wheel of the brake. Hydraulic pressure from the master cylinder acts on the piston, pushing the piston against the shoe, and forcing it against the drum.
When the driver presses the brake, the brake shoe springs return the shoes to their original position.
#4. Brake Shoe.
The brake shoe is made of steel that is welded together. They are used to slow down or stop the car. They are pushed into the drum to generate friction. The backing is secured to the plate, but the wheel is able to slide when pressure is applied from the wheel cylinder.
Each brake has two shoes. The primary shoe is closer to the front wheel of the vehicle. The secondary shoe is closer to the rear wheel of the vehicle.
Advantages of Drum Brakes
- Lower Cost: Drum brake manufacturing is cheaper, holding the price of the car down. This is partly the reason that the drum brake price is more affordable when compared to other braking systems.
- Well-suited to city driving: They’re great in typical stop-and-go traffic with gentle braking.
- Good parking brake: Drum brakes offer better holding power and can be beneficial when the car is parked in an inclined position.
- Longer life in light use: If the car is driven gently, the brake shoes can last longer and may not need frequent replacement.
Disadvantages of Drum Brakes
- Heat accumulation: As the system is closed, heat remains inside, and this can make brakes less effective after a while.
- Weak under heavy use: Their performance can weaken after several uses or over heavy braking, for example, on the highway or a downhill road.
- Not as effective in rain: As water can compromise them, it may slightly hinder braking in wet weather.
- More complicated structure: Drum brakes could have more components in the structure, making them slightly harder to fix or service.
Disc Brake
Motor vehicles are being fitted with disc brakes. Rather than the conventional type of drum brakes, which are commonly used on some cars.
A disc brake usually has a rotating disc and two friction pads. Those are actuated by four hydraulic wheel pistons contained in two halves of an assembly called a caliper.
To apply the brake, hydraulic pressure is applied to the fluid inlet tube, which causes the wheel cylinder pistons to press the friction pads against the rotating disc.
In the released position, the spring holds the piston pads so that they maintain contact with the disc surface. Because the brakes are not self-energizing, more force is needed to apply them for the same brake requirement.
How Disc Brakes Work
- Pressing the brake pedal generates hydraulic pressure in the master cylinder, which contains brake fluid.
- The pressurized fluid passes through the brake lines to the caliper pistons.
- The caliper pistons press the brake pads against the disc or rotor.
- Applying the brake pads against the disc or rotor generates friction, causing the vehicle to slow.
Disc brakes are now standard on the front wheels and are available on all four wheels of many models.
Parts of a Disc Brake
- Brake pads
- Brake rotor
- Caliper
#1. Brake Pads.
Each brake caliper consists of two braking pads, one on each side of the brake rotor. The brake pad has heat-absorbing properties. There is excessive heat generated due to friction between the brake pads and the rotor. It causes the brake pads to wear over time.
#2. Brake Rotor.
When the brake pads come in contact with the brake rotor, the friction force is generated between them. This force works against the wheel rotation. Actually, it works to slow down or even to stop the moving vehicle.
#3. Brake Caliper.
It is the main part of the disc brake that helps to move the brake pad to and from the brake rotor.
When you apply the brake, the caliper will push the pads to the rotor, hence reducing the speed or stopping the vehicle. When you release the brake, the caliper will pull the pads away from the brake rotor.
Advantages of Disc Brakes
- Strong stopping power: Disc brakes offer superior and more consistent braking, and can really save the day in an emergency.
- Improved cooling: They are open, which allows heat to escape quickly, which helps prevent overheating and keeps performance stable.
- Great in the rain: Even in rainy conditions or muddy roads, these clear water off like anything.
- Quick response: Disc brakes respond quickly to the push of a brake pedal, providing improved handling.
- Easy to check and service: The open, simple design makes inspection and cleaning easier, as well as part replacement when needed.
Disadvantages of Disc Brakes
- Increased vehicle cost: Compared to drum brakes, Disc brakes are extremely expensive and may increase the vehicle cost.
- Quicker degeneration: Brake pads have a shorter lifespan and will need frequent replacements.
- Higher maintenance cost: Servicing and replacements, such as pads and discs, can be a bit more expensive in the long run.
- Exposed design: They are more prone to dirt and dust as they are open, and will most probably have to be cleaned whenever you notice some dust on them.
The Main Difference Between Drum and Disc Brake
The following are the differences between drum and disc brake according to their construction, performance, and cost:
#1. Construction.
In a drum brake, it uses a cylindrical drum. When compared to the disc brake, it has a disc-shaped rotor. The drum brake system is a slow braking system. Whereas the disc brake is an instant and fast braking system.
In the case of a drum brake system, it has slower heat dissipation. But in the case of a disc brake, it has faster heat dissipation. In the case of a drum brake, replacing frictional pads is difficult. When compared to a disc brake, the replacement of frictional pads is very easy.
The drum brake uses a hydraulic cylinder to pressurize the friction material against the rotating drum. But the disc brake uses calipers to hold the friction pad against the rotor disc.
#2. Performance.
At high temperatures, the performance of the drum brake will be reduced. When compared to the disc brake, in high-temperature conditions, the performance will not be affected. Hence, better braking will happen.
The design of the drum brake is complex and is used in trucks, buses, and scooters. Whereas the design of a disc brake is simple, and it is used in modern bikes or cars.
The drum brake is operated mechanically and has a self-locking system. Whereas the disc brake is either operated mechanically or uses ABS technology and doesn’t have a self-locking system.
In drum brakes, when we stop the vehicle, it takes more time, which means less efficiency. Whereas in disc brakes, when we stop the vehicle, it takes less time, hence is more efficient.
The torque transmission time in drum brakes is less. When compared to a disc brake, the torque transmission time is high.
#3. Cost.
Drum brake available with low ventilation power and a lower cost. But in the disc brake, better ventilation power and a higher cost.
In the drum brake system, its weight is more, and maintenance cost remains less. But the disc brake is light in weight, and maintenance cost remains high.
Drum brakes use many different fluids in the braking system, so there is no need for maintenance. But disc brakes use fluid in the braking system, so maintenance is required.
Drum Brake vs Disc Brake – Key Differences
Let’s compare drum brake and disc brake:
| Feature | Drum Brake | Disc Brake |
| Design | Closed: Shoes press outward against a drum. | Open: Calipers squeeze pads against a rotor. |
| Heat Handling | Poor: Heat gets trapped inside the drum, leading to “brake fade.” | Excellent: Open design allows air to cool the rotor quickly. |
| Performance (Wet) | Lower: Water can get trapped inside, reducing friction. | Reliable: Centrifugal force flings water off the disc. |
| Braking Power | Moderate (Good for rear wheels/heavy loads). | Strong and consistent (Better for high speeds). |
| Maintenance | Complex: Multiple springs and clips; harder to access. | Simple: Easy to swap pads; visual inspection is instant. |
| Lifespan | Generally longer-lasting pads/shoes. | Pads wear faster but are easier to replace. |
Which is Better – Drum or Disc Brake?
It depends, of course, on where and how you drive. Drum brakes are still sufficient for most scenarios if you do mainly around-town driving in non-extreme conditions (i.e., do not normally brake heavily). This makes them reliable for daily use, and they also help keep the car’s ownership cost in check.
On the flip side, if you go fast, drive on the highway a lot, or want to retain better control of the vehicle in the event of an emergency stop, disc brakes are clearly the better option. They provide much better response and similar performance.
Which is precisely why disc brakes are chosen on the front axle by manufacturers. They are more powerful in front, as the vast majority of braking force goes through the front of the car.