The braking system in a car is essential for safety, as it allows us to slow down the vehicle and come to a complete stop, or avoid an accident or collision. Modern-day drum brakes vs disc brakes are several times more sophisticated than older generation brakes which were basically made from wood.
Today’s cars have drum and disc brakes in common usage and it is not unusual to find cars with a combination of the two types of braking systems. Since the front end of the vehicle has to bear the greater braking force, they are usually fitted with disc brakes, while the rear has drum brakes to safely slow down and stop the vehicle.
Let’s take a closer look at the two types of braking systems and discover the pros and cons of each.
Drum brakes – working and principles
Drum brakes were the first proper brakes on cars that provided vehicles with decent stopping power at the beginning of the century. The components of a drum brake include brake shoes, brake cylinder, pull-off springs, and a housing that is attached to the wheel.
When the brake pedal is pressed, the brake cylinder pushes the brake shoes against the inside of the rotating drum, causing friction and bringing the car to a stop.
Pros of drum brakes
· Drum brakes are more durable than other types due to their increased friction contact area
· They are inexpensive to manufacture and are widely used in vehicles
· The brakes do not require much pressure to work and are well suited to hydraulic systems
· Drum brakes require less maintenance because they are enclosed and kept away from dirt and corrosion.
Cons of drum brakes
· Drum brakes easily overheat in situations like going downhill or during high-speed braking. They do not have adequate cooling mechanisms and the brakes get worn out in these conditions
· With hard braking, the drum expands due to thermal expansion and requires a greater pressure to work, inducing the driver to push on the brake pedal further
· If the brake shoe gets wet or dirty, there is a tendency for it to stick or grab. This may lead to tyres skidding and the driver losing control of the vehicle
· Drum brakes consist of complex components and require a skilled technician for repairs
Advantages of disc brakes
· Disc brakes employ hydraulic systems which require less force to be activated and can apply greater braking force for the vehicle while stopping or slowing down
· There is efficient heat dissipation from the brake pads on the brake discs due to the large surface area of the rotors. Overheating is eliminated and braking is improved even with frequent application of the brakes
· Superior performance in wet conditions. The disc brakes do not grab or stick like drum brakes
· Disc brakes have simple components that are easy to install. Brake pads can be changed at home with simple tools
Disc brakes – how do they work?
Disc brakes are advanced technology that provides superior stopping power and long life for the brakes. First used on racing cars and then adopted in passenger vehicles, disc brakes are the preferred choice for high-performance cars but we are seeing them more often in mass-produced vehicles as well.
Disc brakes consist of a disc rotor, brake calliper, brake pads and a piston. When the brake pedal is applied, hydraulic forces push the piston in the calliper and cause the brake pad to make contact with the disc rotor. The squeezing motion creates friction which slows down the wheel and helps stop the vehicle.
Disadvantages of disc brakes
· Disc brakes are expensive and the costs restrict manufacturers from installing them on all four wheels. They opt to install cheaper drum brakes at the rear
· There is a chance of the brake rotors warping due to heavy braking at high speeds which results in high temperatures followed by immediate cooling. Disc rotor warping can also occur due to improper installation
· Brake pads wear out quite often, much faster than brake shoes on drum brakes. The brake pads exert a powerful squeezing motion on the disc rotors that provide good stopping power, however, they get worn out easily
· They are not useful as parking brakes. When brake pads get hot, they expand and when it is cold, they contract. Parked in one position doesn’t create much heat, so the disc brake won’t hold the wheels in place for a long time period. Some sports cars have a drum brake exclusively for parking despite having all four disc brakes.
If you have a sports car with great amounts of speed and performance, then you probably need disc brakes to slow you down. For regular passenger cars, drum brakes will suffice because they provide decent stopping power and are relatively inexpensive compared to disc brakes.
Disc brakes are expensive due to the machined parts such as polished aluminium and steel and the advanced hydraulic systems that are used to exert enough braking force on the wheels.
Modern manufacturers generally use disc brakes at the front of the car and drum brakes at the rear to keep costs down and to offer a safe braking system for the car.
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