What is the Advantage and Disadvantage of Truck Brake Disc

When driving a trailer through Kentucky, you want to be sure you have ample braking force. While most small trailers rely on the braking force of the towing vehicle, larger trailers should have their own braking system. Let’s compare the trailer braking systems, Disc vs Drum brakes. Whether you’re adding brakes to your trailer, fixing existing ones, or upgrading for better stopping-power, we’ll walk you through everything you need to know to get the job done well with the following disc vs drum brakes information.

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Disc Vs Drum Brakes

What Are Disc Brakes? 

Disc brakes are braking system that is used in various vehicles such as cars, bicycles, and motorcycles. They work using a disc that rotates with the wheel and a caliper with two or more brake pads. 

Are Disc Brakes Better Than Drum Brakes On A Trailer?

The significant advantage of disk brakes is the shorter stopping distance. Depending on the speed, disk brakes can be anywhere from 17% to 33% quicker than drum brakes. Reduced fading is another advantage, especially for vehicles that stop frequently. 

Furthermore, disc brake service and maintenance are often easier and faster than drum brake service and maintenance. Despite all of the advantages of disc brakes, drum brakes also offer certain benefits.

On the other hand, drum brakes are less expensive to install and maintain in comparison to disc brakes. Drum brakes are resistant to water damage and can still function even when the brake lining is worn down.

Disc vs Drum Brakes: Advantages And Disadvantages Of Disc Brakes

Pros

• Easier to maintain: Disc brakes are easier to repair and maintain compared to other types of brakes. 
• Better stopping power: They boost the spotting power substantially. They can generate more friction than other types of brakes, which provides more consistent braking performance. 
• Consistent performance: They are less prone to fading, and they can still work even during an extended period of heavy braking. 
• Less weight: Disc brakes are normally lighter compared to other types of brakes, which helps improve fuel efficiency and reduces wear and tear on the vehicle.

Cons

• Complex: Because of its more complex components than other types of brakes, disc brakes can be more complex to install and repair. 
• More Expensive: They are normally more expensive to replace and install than other types of brakes. 
• Require more force: Disc brakes require more force to operate, which can make them less suitable for certain applications. 

Disc brakes are the go-to choice for many vehicles, especially for vehicles that require reliable and consistent stopping power. They are essential for heavy-duty and high-speed applications. Disc brake performance can make a significant difference in efficiency and safety. 

Disc vs Drum Brakes: How Long Do Disc Brakes Last On A Trailer? 

With proper maintenance generally, disc brakes on a trailer can last anywhere from 30,000 to 50,000 miles or more with proper maintenance and care. These numbers can change depending on several factors. The quality of the components, frequency of use, and conditions in which they are used can affect the lifespan of disc brakes. Harses Services also mentions that disc brakes last about 50,000.

Factors such as load weight, the terrain on which the trailer is driven, and driving styles can also affect the lifespan of the disc brakes. Frequent braking and heavy weight can add strain to the brake system, which can affect the lifespan. 

It is important to maintain the brakes regularly to ensure the longevity of the brakes on the trailer. 

• Keep your disc brakes clean and free of debris.
• Regular inspection for signs of wear.
• Replace brake pads and rotors as needed. 
• Have a professional check the brake system at least once a year. 

What Are Drum Brakes?

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Drum brakes are a type of braking system that uses brake shoes to press against the inside surface of a drum attached to the wheel hub. Hydraulic pressure is applied to the brake shoes, causing them to expand and press against the drum, generating friction and slowing down the trailer wheels and tires when the brake pedal is pressed. 

Disc vs Drum Brakes: Advantages And Disadvantages Of Drum Brakes

Pros

• Good for low-speed driving: Drum brakes generate more braking force at a lower speed.
• Cost-effective: Drum brakes are less expensive in comparison to disc brakes. They’re suitable for lower-cost vehicles. 
• Good for parking: They can be designed to function as parking brakes. 
• Simple design: Drum brakes have a simple design; they are easy to manufacture and repair.

Cons:

• Heat dissipation: Drum brakes are vulnerable to overheating because of their smaller surface area for heat dissipation in comparison to disc brakes. Overheating can cause brake fade and reduce braking performance. 
• Longer stopping distance: Compared to disc brakes, drum brakes have a longer stopping distance. This can be a safety concern, especially in emergency situations. 
• More maintenance: Drum brakes need more maintenance than disc brakes. They tend to gather dirt and debris inside the drum, which can affect braking performance. 
• Heavy: they are typically heavier compared to disc brakes, which can affect a vehicle’s fuel economy and overall performance. 

Disc vs Drum Brakes: How Long Do Drum Brakes Last On A Trailer?

Normally drum brakes on a trailer can last anywhere from 20,000 to 40,000 miles or more with proper maintenance and care. But depending on several factors, these numbers can change.  The quality of the components, the conditions in which they are used, and the frequency of use. With all of that stated, a “typical” situation with a trailer whose brakes start in good working order may provide two to three years of use, depending on whether those miles are highway miles (far less brake usage) or local road miles.

A decent rule of thumb is to check your brakes every time you leave the house and change them no less frequently than replace your tires. I recommend up to 12 months or 12,000 miles between replacements of wearable brake parts.

With proper maintenance, these types of brakes can provide reliable and long-lasting braking performance. However, it is recommended that disc brakes be a better option for trailers carrying heavier loads because of their superior heat dissipation and their strength under harsh conditions. 

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Disc vs Drum Brakes: How do Drum Brakes Work on A Trailer?

When the driver presses the brake pedal, the brake booster (servo system) amplifies the power, and the master cylinder converts it to hydraulic pressure (oil pressure). The pressure is sent to the brakes on the wheels via brake oil-filled tubing (brake fluid). The supplied pressure compresses the pistons on the four-wheel brakes. 

The pistons force the friction materials, known as brake linings, against the inside surfaces of the brake drums, which revolve around the wheels. The linings are forced against the revolving drums, which decelerate the wheels, slowing and halting the vehicle.

Both disc brakes and drum brakes have their own advantages and disadvantages. Whether one is better than the other depends on your trailer and the purpose or uses of your trailer. It is important to weigh the pros and cons of each brake system to determine which type of brake is best for your specific needs.

Disc vs Drum Brakes For Trailers: Effectiveness

There are various factors to consider when comparing disc vs drum brakes. Each kind has advantages and disadvantages that affect multiple users in different situations. 

The planned use of the trailer will have the most impact on the type of brake to use. Disc vs drum brakes, Disc brakes are more suited to vocational vehicles that must negotiate job sites due to their fade resistance. Drum brakes, however, are suitable for long-haul vehicles that benefit from extended service intervals due to their higher longevity.

Disc vs drum brakes both have their own advantages and disadvantages when used on a trailer, so whether one is better than the either all depends on the specific circumstances and requirements of the trailer.

 Disc vs Drum Brakes: Four Winds Trailer

Did you know that the braking system is one of the most important components to decide on when spec’ing a commercial truck? Because heavy-duty vehicles have longer stopping distances — more than the length of two football fields when traveling at 65 mph — the brakes play a vital role in ensuring the safety of the driver and those around them.

Commercial vehicles have air brake systems equipped with drum brakes or air disc brakes (also referred to as ADBs or just disc brakes), or sometimes a combination of the two. Drum brakes have historically come standard on commercial trucks and are the most widely used braking system in the truck industry due to their lower cost and ease of manufacturing. However, the adoption of disc brakes has been steadily growing over the past decade, mostly due to some manufacturers now offering disc brakes as standard on heavy-duty and vocational models because of their superior stopping power and longer life before replacement.

However, there are vocation-specific circumstances in which a specific type of brake may be a better fit. Drum brakes and disc brakes function similarly in that they both turn kinetic energy (the wheel’s movement) into thermal energy (heat) to slow down a vehicle. What differs is the way that heat builds up when friction is applied within the braking system. It’s important to understand the difference between drum brakes and disc brakes and their pros and cons that will impact drivers in different situations.

How Drum Brakes Work

Drum brakes consist of a brake chamber, push rod, slack adjuster, camshaft (S-cam), rollers, a pair of brake shoes, the drum and a return spring. When a driver presses the brake pedal, pressurized air travels to the brake chamber and forces the push rod to actuate the slack adjuster, which in turn rotates the S-cam. As the S-cam rotates, rollers spread the brake shoes apart and force them against the walls of the drum. The friction created by the brake shoes rubbing against the drum slows down the vehicle. Once the driver releases the brake pedal, the return spring pulls the brake shoes away from the drum to allow the wheel to rotate.

Pros and Cons of Drum Brakes

Pros

• Cost – Drum brakes have been in production since the early s and have historically been very popular. Their larger economy of scale typically makes replacement parts cheaper than disc brakes. Drum brakes are also cheaper to manufacture than disc brakes.
• Durability – Drum brakes are generally more durable than disc brakes and require fewer lining replacements because their larger friction contact area helps them to last longer.
• Self-Energizing System – Drum braking systems are self-energizing, meaning the rotation of the drum can forcefully drag one or both brake shoes against the inside of the drum. This increases the vehicle’s stopping power without the driver having to apply extra pressure on the brake pedal.
• Low Maintenance – Because all the components of a drum brake are enclosed within the drum, the parts are more resistant to corrosion and maintenance is simplified.
• Parking – Drum brakes can be engaged while parking without the worry of the brake shoes contracting and the brakes failing.

Cons

• Overheating – One of the biggest downsides to drum brakes is their tendency to overheat quickly in conditions where a driver has to brake frequently. This occurs because the components are housed within the metal drum with limited air circulation. When heat builds up, it can cause the brake shoes to glaze or smooth out and produce less friction, which ultimately increases stopping time. This is referred to as brake fade.
• Wet Weather Performance Issues – The enclosed design of drum brakes causes them to take longer to dry off in wet weather. This exposes the brake shoes to moisture longer.
• Grabbing – Grabbing is a condition in which the drum brake becomes overly sensitive and applies more braking force than required. This can lead to the tires skidding and a loss of control of the vehicle. Grabbing can be caused when the brake shoes are wet or rusty.
• Weight – Drum brakes are generally heavier than disc brakes. The lighter the overall weight of a vehicle, the easier it is to brake.
• Complex Construction – A drum brake has many components that require an expert mechanic for repairs. Inspections are also made more difficult because components are less accessible inside the drum.
• Thermal Expansion – When a driver has to hit the brakes hard, the diameter of the drum expands due to a phenomenon called thermal expansion. This reduces the braking response and the driver must press the brake pedal harder to stop the vehicle.
• More Prone to Failure – Drum brakes are also more prone to failure than disc brakes and cannot be easily fixed by resurfacing the brake shoes. Most of the time the only option is to replace the drum, which can be costly.

How Disc Brakes Work

Instead of using brake shoes and a circular drum to create friction, air disc brakes create friction using a caliper, a disc-shaped rotor and a pair of brake pads. As a wheel spins on a vehicle, the disc-shaped rotor spins with it. When the brake pedal is engaged, compressed air forces a metal piston inside the caliper to clamp down on the brake pads on either side of the spinning rotor with great force. This pressure creates friction between the pads and rotor to quickly slow down or stop the rotation of the wheel. When the brake pedal is released, the caliper releases pressure on the brake pads to allow the rotor to continue spinning.

Pros and Cons of Air Disc Brakes

Pros

• Improved Stopping Distance – With disc brakes, stopping distance can be 17–33% shorter than drum brakes, depending on the speed of the vehicle. Shorter stopping distances are important for keeping the vehicle compliant with the National Highway Traffic Safety Administration’s Reduced Stopping Distance (RSD) rules that require heavy-duty trucks to stop in no more than 250 feet when loaded to max capacity and within 235 feet when lightly loaded. The ability to stop more quickly can also reduce the risk of accidents or decrease their severity.
• Easier Maintenance – Disc brakes are easily accessed without removing the wheel and are built with fewer components, making maintenance and installation faster and simpler.
• Self-Centering and Self-Adjusting – The caliper found inside disc brakes slides from side to side and moves to the center of the two brake pads each time the brake is applied. This leads to more consistent wear of the brake pads and offers more consistent braking over the life of the pads.
• Fewer Compliance, Safety, Accountability (CSA) Violations – Brakes are one of the top five truck components penalized during CSA roadside inspections conducted by the Federal Motor Carrier Safety Administration, which can lead to unnecessary delays and downtime. Because disc brakes do not need to be adjusted, CSA citations for “brakes out-of-adjustment” are eliminated and drivers do not have to worry about them impacting their scores.
• Better Heat Dissipation – Since the rotor is fully exposed to outside air, any heat produced by the friction of the brake pads dissipates into the atmosphere. This prevents overheating of the brakes and improves braking power.
• Less Brake Fade – Because less heat is produced and contained within the braking system, brake pads are less likely to experience brake fade compared to the brake shoes found in drum brakes.
• Standard Performance in Wet Weather – The open-air design of disc brakes allows them to dry off more quickly when wet, reducing the risk of slipping or grabbing.

Cons

• Cost – Disc brakes are much more expensive than drum brakes up front. However, some newer disc brake manufacturers have focused on cutting weight and simplifying the design, which in turn is driving down costs.
• Less Effective as Parking Brakes – Brake pads and rotor discs can expand when heated and contract when cold, making them ineffective as parking brakes. When parked, the brake pads cool off, shrink, and lose contact with the rotor — rendering the brakes ineffective.
• Brake Pad Wear-Out – In some applications, brake pads may wear out more quickly than the brake shoes on drum brakes due to the powerful squeezing force the caliper applies on the pads and rotor. This pressure provides better stopping power but reduced brake pad life.
• Rotor Warping – There is a chance that the rotor may warp when the driver brakes at high speeds. This happens due to very high temperatures on the discs followed by immediate cooling.

Which Type of Brake Is Best for Your Vehicle?

As we’ve demonstrated above, there are many pros and cons to both drum brakes and air disc brakes, but at the end of the day, deciding which option is best for your commercial truck comes down to its intended use. For example, the fade resistance of disc brakes makes them a popular option for vocational trucks driving in environments such as work sites that require frequent braking. Drum brakes, however, are a good choice for long-haul trucks, due to their durability and longer service intervals.

Driving habits, brake duty cycle, operating conditions, compliance and stopping distance are all variables that must be taken into consideration, and the value truck owners put on each of these aspects will ultimately drive their decision on which type of brakes to spec for their vehicles.

A certified technician can inspect the brakes on your truck and recommend the best option based on your specific application and needs. If you’re in the market for a new vehicle, find out which type of brakes come standard on the make and model you’re considering so that you can be aware of the maintenance needs for your specific type of brakes.

Maintaining Your Truck’s Brake System

No matter which braking system you have on your truck, regular maintenance is crucial to ensuring maximum performance and safety and increasing the life of your brakes. Ignoring brake issues can lead to breakdowns and accidents that cause harm, downtime, loss of revenue and potential violations. In , over 25% of out-of-service violations found during the Commercial Vehicle Safety Alliance’s Brake Safety Week were due to brake-related issues.

You can make sure your brakes remain in good condition by inspecting for worn-out, damaged or rusted components; listening for unusual noises when pressing the brake pedal; and watching for warning signals on the dashboard.

Rush Truck Centers offers same-day brake system inspections and service at our locations across the U.S. Our dedicated technicians will focus on your brake system and conduct a comprehensive inspection on brake pads, rotors, brake shoes, and drums and provide per-axle prices for parts and labor. Learn more about our brake inspection services to ensure your truck’s braking system is in peak condition, or contact us today to request a service appointment at one of our more than 140 locations nationwide.

Contact us to discuss your requirements of Truck Brake Disc. Our experienced sales team can help you identify the options that best suit your needs.