What are disc brakes?
Disc brakes are braking systems in which brake pads are pressed against a rotating brake disc to slow down the vehicle. The brake disc is attached to the wheel hub and rotates together with the wheel. When the driver applies the brakes, the brake calipers press the brake pads against the disc, creating friction and slowing down the truck.
Nowadays, disc brakes are increasingly used on modern trucks, especially on the front axle and in international transport.
How do disc brakes work on a truck?
The system consists of:
When the driver presses the brake pedal, the air pressure activates the brake caliper. The brake pads are then pressed against the disc, slowing down the wheel.
Advantages and disadvantages of disc brakes
Disc brakes provide strong braking performance and respond quickly, making them particularly suitable for trucks that travel long distances or carry heavy loads. Because the brake disc is exposed, heat can dissipate more effectively than with drum brakes. This reduces the risk of overheating and brake fade during intensive braking. Disc brakes also perform better in wet conditions, as water and dirt are removed more quickly. In addition, maintenance is often easier because brake pads can be replaced faster and wear is easier to inspect.
However, there are also some disadvantages. Disc brakes are generally more expensive to purchase, and parts often wear out faster, especially in heavy city traffic or intensive use. Furthermore, the open system is more sensitive to dirt, road salt, and stone chips from outside influences.
Where are disc brakes commonly used?
Disc brakes are mainly used in:
- International transport
- Long-haul trucks
- Modern tractor units
More and more manufacturers now choose disc brakes as standard on new trucks due to stricter safety requirements and improved performance.
What are drum brakes?
Drum brakes work differently from disc brakes. In this system, brake shoes press against the inside of a closed brake drum to slow down the vehicle.
The brake drum rotates together with the wheel. When braking, the brake shoes move outward against the inner wall of the drum. The resulting friction slows down the wheel.
Drum brakes have been used in the transport industry for many years and are still popular for certain types of trucks and trailers.
How do drum brakes work on a truck?
The system consists of:
When the driver presses the brake pedal, the air pressure activates the braking mechanism inside the drum. The brake shoes then move outward and press against the inside of the rotating brake drum. The friction slows down the wheel and reduces the truck’s speed.
Advantages and disadvantages of drum brakes
Drum brakes are known for their long service life and low maintenance costs. Because the braking system is largely enclosed, the components are better protected against dirt, mud, water, and stone chips. As a result, parts often wear out less quickly than with disc brakes. Drum brake components are also generally cheaper to purchase and maintain. In addition, drum brakes have a strong parking brake function because they can hold a large amount of braking force. This is why they are still widely used on trailers, semi-trailers, and vehicles operating under heavy-duty conditions.
However, drum brakes also have some disadvantages. Because the system is enclosed, heat cannot dissipate as effectively, increasing the risk of overheating during prolonged or heavy braking. Maintenance is also often more complex, as replacing brake shoes and springs takes more time than replacing brake pads on disc brakes. Drum brakes also generally respond slightly less directly than disc brakes.
Where are drum brakes commonly used?
Drum brakes are widely used on:
Due to their robust construction, drum brakes remain popular in harsh working environments with a lot of dirt and dust.
What is the biggest difference between disc brakes and drum brakes?
The biggest difference lies in how braking force is generated and how heat is dissipated.
| Disc Brakes |
Drum Brakes |
| Open system |
Closed system |
| Fast heat dissipation |
Heat remains longer |
| Faster braking response |
Slightly slower braking response |
| Higher purchase costs |
Lower costs |
| Easier maintenance |
More complex maintenance |
| Often used on modern trucks |
Commonly used on trailers |
How can you recognize wear on truck brakes?
Worn brakes can cause dangerous situations. Pay attention to the following warning signs:
- Squealing or grinding noises
- Reduced braking power
- Vibrations while braking
- Overheated brakes
- Uneven tire wear
- Warning lights on the dashboard
Regular inspection of brake discs, brake pads, brake drums, and brake shoes helps prevent high repair costs and downtime.
Conclusion
Both disc brakes and drum brakes have their own advantages and applications within the transport industry. Disc brakes offer powerful performance, better cooling, and fast response, making them ideal for modern long-haul trucks. Drum brakes, on the other hand, are durable, cost-effective, and highly resistant to harsh working conditions.
The best braking system depends entirely on the type of truck, its application, and the requirements regarding maintenance, safety, and costs.
Are you looking to replace parts or searching for truck brakes from brands such as DAF, Scania, Volvo, Mercedes, or MAN? Then it is important to choose high-quality parts that match your application and type of transport.
