Drum brakes are a type of brake system, which has a drum (brake drum) that rotates with the wheels of your vehicle. The brake drum encompasses several elements like brake shoes with brake linings and pistons, which work together to produce friction and stop your vehicle.
Components of a drum brake
A drum brake system consists of several components. They include the following:
Backing Plate
This is a metal band often made of steel. It provides a firm grip and protection to the drum brake components. The braking plate protects the drum brake system from debris and dirt.
Master cylinder
A wheel cylinder is a component of the drum brake system that contains pistons. When hydraulic pressure is exerted from the master cylinder, it causes the pistons to push the brake shoes towards the brake drum.
Wheel cylinder
A wheel cylinder is a component of the drum brake system that contains pistons. When hydraulic pressure is exerted from the master cylinder, it causes the pistons to push the brake shoes towards the brake drum.
Brake shoes
These components of a drum brake system contain a frictional material known as brake linings. Pistons push brake shoes, which causes the brake lining to press against the brake drum and stop the vehicle. The brake lining is often made of semi-metallic, ceramic, and non-asbestos materials.
If you have a heavy vehicle, such as a trailer, you should consider getting high-quality brake linings material to improve your drum brake system.
Return spring
The return spring is the component responsible for restoring the brake shoes to their position. After you release the pedal, the spring pulls back the brake shoes, releasing your wheels.
How drum brakes work
When you press your pedal, the master cylinder exerts hydraulic pressure, which pushes the wheel cylinder containing pistons towards the brake shoes. The brake shoes contain a frictional material called brake lining. The pistons push the brake shoes outwards towards the brake drum. The brake lining presses against the rotating brake drum, which decelerates the wheels due to friction.
The drum brake system also has return springs that pull back the brake shoes to release the wheel and restore them to their position when you release the pedal.
Types of drum brakes
There are different types of drum brakes. They include:
Hydraulic drum brakes
These are the most common type. They use hydraulic pressure exerted by the master cylinder to bring your wheels to a halt.
Mechanical drum brakes
These types of brakes use mechanical force to push the brake shoes against the brake drum, which brings your wheels to a stop
Pneumatic assisted drum brakes
This type of brake is also known as the S-Cam brake system. This type of brake uses compressed air to exert pressure on the brake shoes to stop your vehicle. Heavy commercial vehicles commonly use these types of brakes.
How long does a brake drum system last?
If you have a heavy commercial vehicle like a bus, you could be wondering how long your drum brakes can last. A typical drum brake can last for up to 150,000 to 200,000 miles when properly maintained.
You can ensure proper maintenance by inspecting the brake fluid level and readjusting the brake shoes to enhance contact with the brake drum. However, this depends also on the conditions that your truck experiences. You can also regularly inspect your brake linings to ensure they are effective.
For instance, if you drive your bus on rough terrain regularly, your drum brakes are likely to wear out in a shorter period.
Brake shoes can take longer to be replaced. You will need to replace them after about 30,000 to 40,000 miles.
Drum brakes are one of the effective braking systems that you can use on your commercial vehicle. All the components of these brakes are essential to promote the drum brakes’ functionality. The pneumatic assisted drum brakes are most likely the better option for your trailer. If you require assistance with your drum brakes and commercial brake linings, call us today!
