When was the last time you had your brake drums inspected? Like other brake components, drum brakes are vital in ensuring your braking system functions correctly. The key to a healthy braking system lies in discovering how the components work.
In this article, we will address several aspects of brake drums, including how they work, their types, maintenance tips, and much more. We will equip you with the knowledge you need to understand and maintain your brake drums. Learn more below.
Brake drums are cylindrical metal casings attached to your vehicle’s wheels. The brake drums rotate with the wheels when your car is in motion. The brake drum encircles a set of brake shoes with frictional materials called brake linings.
These materials press against the inner surface of the brake drum, generating friction, ultimately slowing down or stopping your car. Brake drums are common in the rear wheels of most vehicles.
When you press the brake pedal, hydraulic pressure is transmitted to the brake cylinder through the brake lines. The cylinder then forces the piston to press the brake shoes against the inner surface of the brake drum. This frictional contact causes the vehicle to slow down or stop.
The brake linings attached to the brake shoes enhance braking efficiency and reduce wear on the shoes and the drum.
The brake drum consists of several components. They include:
The drum shell is the outer cylindrical component of the brake drum. It houses the other brake components and is attached to the wheel of your vehicle. The drum shell is typically made from durable materials like cast iron, steel, or aluminum.
This is the interior part of a brake drum that the brake shoes come into contact with during braking. The friction surface is typically smooth and flat to ensure proper contact with the brake shoes
The flange is the outer part of the brake drum that keeps the braking components in place. The flange also provides additional support to the drum structure.
Brake drums are available in different types, each designed to suit various driving conditions and vehicle applications. We will explore different types of brake drums based on various aspects.
Below are types of drum brakes based on their material.
These are the most common type of brake drums. Cast iron brake drums are popular for their durability and excellent heat resistance. They are suitable for regular vehicle applications and standard driving conditions.
Composite brake drums are made from several materials, including reinforced carbon or aluminum. These brake drums are lighter and ideal for high-performance vehicles.
Brake drums have different designs. Below are some drum brake designs you can consider.
Solid brake drums are the traditional type of brake drums. These drums have a solid, continuous structure without ventilation or cooling openings. They are typically made from cast iron, steel, or other durable materials.
Solid brake drums are common in older vehicles or heavy-duty applications. These brake drums can be prone to heat buildup during prolonged or heavy braking.
These drums feature openings or fins on the exterior surface. The vents allow air to flow through the drum, which helps dissipate heat more efficiently. Vented brake drums can handle higher brake loads and provide better braking performance during demanding driving conditions or heavy braking.
Here are different types of drum brakes based on their operation.
In a single-leading shoe brake drum, the primary brake shoe is located at the front of the brake drum during rotation. When you apply the brakes, the leading shoe presses harder against the drum due to its position, generating braking force.
The trailing shoe, located at the rear of the drum, provides additional support but does not contribute significantly to the braking effect. Leading shoe brake drums are common in older vehicles.
A twin-leading brake drum features two leading shoes, one on each side of the drum’s interior surface. Both leading shoes actively generate braking force. This design provides a greater braking force than the single-leading shoe brake drum.
In a duo-servo brake drum setup, both the leading and the trailing shoes move outward when you apply the brakes. This system works in contrast to a standard leading-shoe brake drum, where only the leading shoe generates braking force.
Duo-servo brake drums are popular for their powerful braking capabilities. They are common in heavy-duty vehicle applications.
Brake drums and brake discs are two different braking systems used in vehicles. Let us compare the two types of braking systems.
Brake discs offer better performance and quicker stopping power compared to brake drums. They are less likely to experience brake fade and provide consistent braking in various conditions.
Brake drums are relatively easier to maintain than brake discs. However, they require more frequent inspection and adjustments compared to brake discs.
While brake drums provide reliable braking power, they are also prone to developing problems over time. Recognizing the warning signs earlier can help you prevent worse issues. Here are the signs you should watch out for.
Do you notice vibrations every time you step on your brake pedal? If so, your brake drums might need attention. Warped brake drums can cause an inconsistent friction surface for the brake shoes, resulting in vibrations.
If your vehicle takes longer than usual to slow down or stop, your brake drums could be damaged. Consider calling a professional to inspect your brakes and address any issues immediately.
If you notice brake fluid around your vehicle’s wheels, it could indicate issues with your brake drum or other brake components.
If you notice strange screeching or scraping sounds when you apply the brakes, you should consider getting your brake drums checked. When the brake lining on the brake shoe wears out, the metal backing contacts the brake drum directly, causing scraping or grinding noises.
You can extend the life of your brake drums by following these tips.
Regular Cleaning and Lubrication – Keep the brake drums clean and free from debris and apply suitable lubricants to moving parts for smooth operation.
Brake Fluid Inspection – Maintain the correct brake fluid level to ensure consistent hydraulic pressure for effective braking.
Regular Inspections – Frequently examine the brake drums for signs of wear, damage, or uneven surfaces. Look for grooves, scoring, or any abnormalities that might affect brake performance.
Here are some common brake drum issues.
Yes, brake drums can be repaired in some cases. However, if the brake drum is severely worn, you should replace it with a new drum to maintain safe and effective braking.
Brake drums can break due to various reasons, including:
If you don’t replace worn or damaged brake drums, braking performance reduces, leading to longer stopping distances and reduced control. You also put your safety at risk by driving with damaged brake drums.