Understanding the Components, Functions, and Types of Drum Brakes!

The drum brakes system in a car is one type of braking system used to stop the movement of the vehicle. This system consists of components such as brake drum, brake shoes, wheel cylinder, springs, and a pull mechanism. When the brake pedal is pressed, the brake fluid will activate the wheel cylinder, which in turn forces the brake shoes to press against the inner surface of the brake drum, slowing down the movement of the car.

drum brake systems are more commonly used in older cars or on the rear wheels, while disc brakes are more frequently used in modern cars or on the front wheels. However, some car manufacturers still utilize this brake system because it is simple, reliable, and less expensive to produce.

Components of the drum brakes System in a Car

Here is an explanation of the main components of the drum brakes system in a car:

Backing Plate

The backing plate serves as a housing for these brake components. It is usually made of cast iron or other metal materials and is located inside the brake drum.

Wheel Cylinder

The wheel cylinder is responsible for moving the brake shoes towards the brake drum. When the brake pedal is pressed, brake fluid flows through the brake hose and enters the wheel cylinder, thus moving the brake shoes to press against the drum brakes.

Brake Shoes & Pads

Brake shoes are the components that directly interact with the drum brakes. They are typically made of friction materials, such as asbestos, and coated with substances that generate friction against the brake drum. Brake pads are located inside the brake shoes and are usually made of metal or materials that create friction with the brake drum.

Return Spring

The return spring is responsible for returning the brake shoes to their initial position after the brake pedal is released. This spring is located between the two brake shoes and connected to both the brake shoes and the backing plate.

Brake Shoe Holder

The brake shoe holder ensures that the brake shoes are held in the correct position. It is located on the top of the brake shoes and connected to the backing plate.

Brake Shoe Adjuster

The brake shoe adjuster is used to adjust the distance between the brake shoes and the drum brakes. This adjuster is located between the two brake shoes and connected to the backing plate. When the brake shoes wear out, the adjuster can be used to reposition them and maintain the proper distance from the brake drum.

Parking Brake Lever

The parking brake lever is used to lock the rear wheels and prevent movement when the car is parked. This lever is usually located in the middle of the car’s cabin and connected to the parking brake cable.

Drum

The drum serves as the surface for the brake shoes to generate friction. It is made of metal and positioned at the rear of the car’s wheels.

Parking Brake Cable

The parking brake cable connects the parking brake lever to the brake shoes. It is made of strong steel wire and runs along the car’s frame to the rear wheels. When the parking brake lever is engaged, the cable pulls the brake shoes towards the brake drum, locking the rear wheels in place.

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What is the Function of Drum Brakes?

The primary function of the drum brakes system in a car is to stop the vehicle’s movement and keep it stationary. When the brake pedal is pressed, the brake fluid activates the wheel cylinder, which in turn forces the brake shoes to press against the inner surface of the brake drum, slowing down the movement of the car.

In addition to this primary function, brake drum also have several additional functions, which include:

Preventing the car from rolling when parked

These brakes are equipped with a parking brake lever that can lock the rear wheels, preventing the car from rolling when parked.

Maintaining vehicle balance

Drum brakes, especially those on the rear wheels, help maintain the balance of the car during braking and prevent aquaplaning.

Longer lifespan

This brake system tends to be more durable and can last longer than disc brakes, especially in everyday driving situations.

More effective at low speeds

Drum brakes are generally more effective at low speeds. At higher speeds, the friction generated between the brake shoes and the drum brakes may not be sufficient to stop the car quickly.

In some cases, brake drum can also be used on the front wheels of a car, although this is less common and more frequently seen in older vehicles or cars with rear-wheel drive configurations.

Types of Drum Brakes

Here is an explanation of several common types of drum brakes used in cars:

Leading and Trailing Shoes

This type of drum brakes has different-sized and shaped brake shoes, with a larger curved shoe in the front and a smaller one in the rear. When the brake pedal is pressed, the front shoe presses against the inner surface of the brake drum first, followed by the rear shoe.

Single Leading Shoe

As the name suggests, this type of brake has only one shoe at the front of the drum brakes, while the rear portion is empty. The front shoe is designed to press against the inner surface of the brake drum and slow down the movement of the car.

Two Leading Shoes

This type of brake has two equally sized and shaped shoes at the front of the drum brakes. Both shoes press against the inner surface of the brake drum simultaneously when the brake pedal is pressed.

Dual Fixed Cylinder

This type of drum brakes system uses two wheel cylinders to press the brake shoes against the inner surface of the brake drum. The wheel cylinders are connected to two fixed shoes mounted on the backing plate.

Uni Servo

This type of brake drum utilizes a single wheel cylinder connected to both the front and rear shoes. The rear shoe is larger and curved to provide stronger braking effect.

Dual Servo

This type of drum brakes system uses two wheel cylinders, each connected to the front and rear shoes respectively. The front shoe is smaller and flat, while the rear shoe is larger and curved to provide stronger braking. This type of drum brakes is more effective and commonly used in modern cars.

To maintain the performance of the drum brakes system in your car, it is essential to perform routine maintenance. One way to ensure good maintenance is by using the Vehicle Maintenance System from TransTRACK.

With TransTRACK, you can monitor the maintenance schedule for the drum brakes system and other components of your car. You will also receive notifications when it’s time for maintenance, allowing you to take prompt action to prevent damage or failure in the drum brakes system.

So, make sure to use the Vehicle Maintenance System from TransTRACK to help monitor and maintain the performance of the drum brakes system in your car. By performing routine maintenance and utilizing TransTRACK, you can ensure that your car is always safe and comfortable to use.