What is the difference between drum brakes and disc brakes in cars?
2 Answers
Differences between disc brakes and drum brakes: 1. Different braking principles: Drum brakes involve installing two semi-circular brake shoes inside the wheel hub, using the "lever principle" to make the brake shoes contact and rub against the inner surface of the drum for braking. Disc brakes use a brake caliper to control two brake pads that clamp onto the brake rotor attached to the wheel. When the brake pads grip the rotor, friction is generated between them. 2. Different heat dissipation performance: Drum brake systems can operate with lower hydraulic pressure. However, when heated, the drum's diameter expands, which may lead to less responsive braking than expected. Disc brakes have superior heat dissipation compared to drum brakes, preventing brake fade and failure during continuous braking.
I've been driving for many years and have used quite a few vehicles with drum brakes and disc brakes. Drum brakes are shaped like a large drum, slowing the vehicle by pressing the brake shoes against the drum wall. They are simple in structure, inexpensive, and easy to maintain and replace parts. However, their biggest drawback is poor heat dissipation. During prolonged braking, such as on downhill roads, they are prone to heat fade, leading to weakened or even failed braking performance. Disc brakes are completely different. They use calipers to clamp onto disc-shaped brake pads, acting like a clip. They dissipate heat quickly, are highly efficient, don’t accumulate water in rainy conditions, and offer much more responsive braking. Most new cars nowadays use front disc and rear drum brakes or all-disc brakes. When I drive an SUV, disc brakes provide safer and more reliable performance during high-speed emergency stops. However, disc brakes come with slightly higher costs and maintenance, with lower part replacement frequency but higher labor costs. From personal experience, disc brakes better meet modern driving demands.
