Technopedia

Brake System: Comparison Between Disc Brakes and Drum Brakes
This overview compares the two main types of braking systems—disc brakes and drum brakes—highlighting their key components and how they function.

Disc Brake System

Disc brakes are widely used on modern vehicles due to their strong stopping power and resistance to heat.
Key Components:

Caliper: The hydraulic device that houses the brake pads and clamps them against the rotor to create friction.

Brake Pads: Friction material that presses against the disc (rotor) to slow down the vehicle.

Rotor (Disc): The metal disc that rotates with the wheel and is squeezed by the brake pads to stop the vehicle.

Drum Brake System

Drum brakes are often used on rear wheels of economy cars and many heavy-duty vehicles because they are durable and cost-effective.
Key Components:

Brake Shoes: Curved friction elements that expand outward to press against the inside of the brake drum.

Wheel Cylinder: A hydraulic piston that pushes the brake shoes outward when the brake pedal is pressed.

Brake Drum: The rotating cylindrical housing that the shoes press against to produce stopping power.

Automatic Adjuster: A mechanism that maintains the correct distance between the shoes and the drum as the shoes wear down.

Disc brakes generally offer better cooling, performance, and consistency, while drum brakes provide strong braking force at a lower cost and remain common in many rear-wheel applications.

Leaf Spring – Exploded View
A leaf spring is a suspension component widely used in many vehicles—especially older cars, trucks, trailers, and off-road machines. It consists of multiple flat steel strips, called leaves, stacked together and clamped into a single unit. This assembly is mounted to the vehicle’s axle and works to absorb shocks and vibrations from the road, helping deliver a smoother and more stable ride.
Key Points About Leaf Springs:

Structure:
A leaf spring is made up of several flat steel leaves of different lengths, arranged in a semi-elliptical shape. The longest leaf is the main leaf, which includes eyelets at both ends for mounting.

Function:
Leaf springs serve as both a spring and a linkage. They support the vehicle’s weight while allowing controlled suspension movement. By absorbing bumps and road irregularities, they reduce stress on the chassis and improve ride comfort.

Applications:
These springs are widely used in heavy-duty vehicles—such as trucks, buses, and some 4x4s—due to their strength and ability to handle large loads. Although many modern vehicles now use coil springs, leaf springs remain popular where durability and load capacity are essential.

Maintenance:
Regular inspection is important. Wear, cracks, rust, or broken leaves can reduce performance and may lead to a harsh ride or even suspension failure.

In summary, leaf springs are a crucial part of many suspension systems, providing stability, durability, and strong load-carrying capability—especially in vehicles built for heavy work or rough terrain.

Understanding Car Suspension System: Key Parts & How They Work