Brakes are critical in ensuring the safety of motor vehicles. After all, cars don't only need to go fast but also to stop just as quickly when needed. In that regard, drum brakes and disc brakes are two of the most common types, but which is better?
Drum brakes have their components in a drum attached to the wheel. Those components push outwards to generate friction and slow the vehicle, while disc brakes clamp on a turning rotor to create the same effect.
Both are excellent, but disc brakes have better stopping power, particularly at high speeds. Drum brakes are contained, making them better for off-roading to keep the mud out of the system.
There’s more to both drum and disc brakes than meets the eye. So, check out this guide to learn how each one works and their pros and cons.
What Are Drum Brakes, and How Do They Work?
Firstly, let’s take a closer look at drum brakes. This kind of brake system has been around for a very long time. Disc brakes replaced them, but you’ll still find drum brakes being used in many vehicles alongside the newer type of brakes.
As the name suggests, this brake system consists of a drum that rotates with the wheel to which it's attached. Inside the drum, you'll find brake shoes that expand outward when you press down on the brake pedal.
As that happens, the brake shoes push up against the brake lining to produce friction, reducing the wheel's speed until it comes to a complete halt.
The outward expansion of the brake shoes happens thanks to the piston sitting inside the brake drum. The piston reacts to the pressure you apply on the brake pedal, causing the brake shoes to create friction and slow the wheel down.
Drum brakes aren't the primary kind of brakes used in cars these days, but they haven't disappeared completely. They are often used in conjunction with disc brakes and installed to the rear wheels. Meanwhile, most front wheels use disc brakes, which we will explore later in this article.
What Are the Pros and Cons of Drum Brakes?
Drum brakes, like any other components in your car, come with their fair share of benefits and drawbacks.
Some of the benefits or pros of drum brakes are the following:
- Lower manufacturing costs: Firstly, drum brakes are much more affordable for manufacturers to produce, reducing the overall cost of the vehicle.
- Recondition potential: Damaged drum brakes are much easier to recondition or repair to full functionality, which is not the case with disc brakes, as you’ll see later in this guide.
- Less force required: By design, drum brakes produce much more friction, meaning, they require less braking force to bring your car to a halt.
- Parking brake: Drum brakes make it much easier to accommodate your car’s parking brake. It doesn’t take much space, and that’s why many car models use drum brakes as their parking brakes, to begin with.
Naturally, drum brakes have downsides that include:
- Heat dissipation: Drum brakes get their name from the drum design, which also keeps heat trapped inside the system, making it difficult to dissipate heat. As you can imagine, too much heat in any mechanical part is not a good thing.
- Rust and buildups: The drum design also causes another issue - it allows moisture, dirt, and debris to remain trapped inside. Despite how the wheel turns, those things can’t fall out naturally.
- Faster wear: Drum brakes also have a shorter lifespan than disc brakes, partially because of the issues above but also because they generate a lot of friction.
- More points of failure: Despite the lower manufacturing costs, drum brakes consist of more different components. Unfortunately, that means they have more points of failure. In simpler terms, it can fail in more ways because it has many other parts.
How Do Disc Brakes Work?
Disc brakes are much more common in today’s vehicles, whether we’re talking about cars, trucks, or even motorcycles. They work using a mechanism that’s different from drum brakes.
Disc brakes have three main parts: the brake rotor, brake pads, and brake callipers.
While drum brakes components push outwards to generate friction and reduce the wheel’s speed, disc brakes work externally.
First, the brake rotor turns along with the wheel. When you apply pressure on the brake pedal, the callipers squeeze the brake pads against the rotor, generating the friction necessary to slow the wheel down and bring your vehicle to a complete stop.
Unlike drum brakes, the main components in a disc brake system are exposed, a design that affords the system plenty of important benefits.
What Are the Pros and Cons of Disc Brakes?
Disc brakes are popular for several reasons, including these advantages:
- Better braking power: The design of disc brakes creates much more stopping power, even with smaller-sized units. They’re more effective at braking from high speeds, making them suitable for high-performance vehicles.
- Heat dissipation: The open design also means disc brake systems can release heat into the surrounding atmosphere efficiently, thereby preventing overheating.
- No buildups: Also owed to the open design is the benefit that dirt, debris, and moisture don't build up around the brake. Everything falls to the ground thanks to gravity.
Disc brakes do fall behind due to their disadvantages, which include:
- Higher Costs: The benefits of disc brakes come at a cost, which increases the overall price tag for vehicles with them.
- Brake Fluid Changes: Disc brakes also require relatively more frequent brake fluid replacements, as the fluid tends to get less viscous (i.e., thicker) relatively sooner.
- Air in the Master Cylinder: Air penetrating the master cylinder can cause the system to fail, which means it’s necessary to bleed the brake system.
Drum Brakes Vs Disc Brakes: Which Is Better?
As with many things in the automotive world, the answer to whether disc or drum brakes are better is “it depends”.
Remember that despite the prevalence of disc brakes, drum brakes are still used in many cars, often together with disc brakes.
Still, drum brakes are better for off-roading because they’re contained and therefore protected from the loose mud and other debris kicked up by the tyres. However, vehicles requiring powerful, high-speed braking, like race cars and commercial trucks, are much better off using disc brakes.
For most regular drivers, whatever brakes come with the car are more than sufficient. However, off-roaders and racers can consider brake conversion kits if the stock brakes aren’t good enough for their needs.
Regardless of the brake type you have in your car, you can find all the necessary replacement parts through CarpartAU. Check out the Part Finder for the best deals on new parts, or browse the Marketplace for excellent offerings on used ones instead!
By Ray Hasbollah