Drum Brake Assembly

A drum brake assembly is a braking system used in vehicles. It consists of a hollow drum attached to the wheel and brake shoes fitted inside the drum. When the brake pedal is pressed, the shoes expand against the drum's inner surface, generating friction to slow down or stop the vehicle.

Types of Drum Brake Assembly

Operation Principles of Drum Brake Hub Assembly

Brake Pedal Activation:

Pressing the brake pedal initiates hydraulic pressure, transmitted to the drum wheel cylinder via brake lines.

Wheel Cylinder Expansion:

Hydraulic pressure forces the pistons in the wheel cylinder to expand, pushing the brake shoes outward.

Brake Shoe Contact

The brake shoes, as one of the drum brake assembly parts, equipped with friction material, press against the inner surface of the brake drum.

Friction Generation:

The friction between the brake shoes and drum converts kinetic energy into heat, slowing down the vehicle.

Reverse Movement:

When the brake pedal is released, springs retract the brake shoes, allowing the vehicle to move freely.

Emergency Brake Activation:

Mechanisms separate from hydraulic system engage the automatic parking brake function, locking the brake shoes in place for parking.

Heat Dissipation:

Drum brake's design aids heat dissipation via ventilation holes in the drum, preventing overheating during prolonged use.

Self-Adjustment Mechanism:

Automatic adjusters maintain optimal shoe-to-drum clearance, ensuring consistent braking performance as the linings wear down.

Advantages of Drum Brake Caliper Assembly


Car drum brake assemblies are generally more economical to manufacture, making them a popular choice for vehicles where cost is a significant factor.

Protection from Elements:

Enclosed design of drum brakes provides better protection against water, dirt, and debris, extending their longevity in certain conditions.

Parking Brake Function:

Drum brakes often serve as an integrated parking brake, simplifying the braking system and enhancing vehicle safety during parking.

Simple Design:

The simplicity of electric brake drum assembly makes them easy to install, maintain, and repair, reducing complexity in vehicle maintenance procedures.