The brake drum system consisting drum, wheel brake cylinder (brake center), pistons inside the brake cylinder, shoes, pads, return springs. In addition, the handbrake mechanism is located on the brake plate. Drum: It is a metal part, usually made of cast iron, that rotates with the wheel. It is mounted on the wheel hub with lug studs. The inner surface of the drum forms the friction surface of the pads.
Wheel Brake Cylinder: This is also called the brake center in the industry (not the brake master center), the brake hose is connected to the brake cylinder with a union. By converting the hydraulic pressure into a thrust with the pistons inside, it presses the pads to the drum.
Brake Shoes: It is a half-moon shaped metal piece on which the pads are riveted or glued. The piston brakes by pushing the shoes forward, and the return spring retracts the shoes.
Brake Pads: It is the part on the shoes that opens outward with the shoe when the brake is pressed and rubs the drum, has a high friction coefficient and creates the braking effect.
Return springs: These are the springs that open outwards when the brake pedal is pressed and bring the brake shoes in contact with the drum back to their normal position by pulling back when the brake is released.
The drum brake system is the brake mechanism used on the rear wheels of passenger cars and light commercial vehicles and heavy vehicles. The brake mechanism is fixed, the drum rotates with the Wheel. When the brake pedal is pressed, pressurized hydraulic brake fluid opens the pistons (right-left) in the wheel brake cylinder located on the brake plate, pushing the brake shoes towards the drum. The brake pads on the outer surface of the shoes create the braking effect by rubbing against the inner surface of the drum.
Drum brakes are overheat because operate in the closed area and are difficult to cool, when it warms up, the braking force decreases. In addition, since the drum mass is high, it increases the unsprung mass (except the suspension), which has a negative effect in terms of comfort.
This feature is not available for disc brakes. In addition to the braking force obtained by pressing the brake pedal in the drum brake system; An additional braking effect occurs due to the rotation direction of the drum and the way the pads contact.
While the drum is turning to the left (ie the vehicle is moving forward), the pistons in the wheel brake cylinder open the brake shoes both to the left and to the right when the brake is applied. Since the direction of rotation is to the left, the brake pad on the left tends to rotate together with the drum when pressed against the drum, that is, it creates a pressure in the direction of friction in addition to the brake thrust, thereby creating a self-braking effect and increasing the braking force of the vehicle. Because of this extra braking, the left pads generally wear out more than the right pads.
At the same time, the brake pad on the right is also pressed to the drum, but here, the opposite of the above logic; The drum shows a pushing effect against the lining, which acts in the opposite direction due to the direction of rotation. For this reason, the brake pad on the right side has less braking effect and wears less than the pad on the left.
Various designs are used in drum brakes with double cylinder (one on top and one on the bottom), single cylinder (only on the top), single acting cylinder or depending on the structure of the studs of the shoes. The most used drum brake type: single cylinder and self-adjusting type.
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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.
Here is an explanation of the main components of the drum brakes system in a car:
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.
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 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.
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.
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.
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.
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.
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.
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.
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:
These brakes are equipped with a parking brake lever that can lock the rear wheels, preventing the car from rolling when parked.
Drum brakes, especially those on the rear wheels, help maintain the balance of the car during braking and prevent aquaplaning.
This brake system tends to be more durable and can last longer than disc brakes, especially in everyday driving situations.
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.
Here is an explanation of several common types of drum brakes used in cars:
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.
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.
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.
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.
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.
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.
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