Why are drum brakes not used anymore?
Drum brakes, once a common feature in automobiles, have largely been replaced by more advanced disc brake systems in modern vehicles. This shift has occurred due to several key advantages that disc brakes offer over their drum-based counterparts.
The Decline of Drum Brakes
Drum brakes, which use a set of brake shoes that press against the inner surface of a rotating drum, were the predominant braking system in vehicles for many decades. However, as technology progressed, the limitations of drum brakes became increasingly apparent, leading to their gradual replacement by disc brakes.
Advantages of Disc Brakes
Disc brakes, which use calipers that clamp down on a rotor attached to the wheel, offer several key advantages over drum brakes:
- Better Cooling: Disc brakes are more effective at dissipating heat, which is crucial for maintaining consistent braking performance, especially during prolonged or heavy braking.
- Improved Fade Resistance: Disc brakes are less prone to brake fade, a phenomenon where the braking force decreases due to excessive heat buildup.
- Faster Response: Disc brakes can respond more quickly to the driver's input, providing a more immediate and precise braking feel.
- Greater Durability: Disc brakes generally have a longer lifespan and require less maintenance compared to drum brakes.
- Enhanced Wet Weather Performance: Disc brakes are less affected by water and debris, maintaining their effectiveness in wet conditions.
These advantages have made disc brakes the preferred choice for the majority of modern vehicles, leading to the gradual phasing out of drum brakes in most applications.
Exceptions and Niche Applications
While drum brakes are no longer the industry standard, they do still have some niche applications. Drum brakes may be used on the rear wheels of some vehicles, particularly in budget-oriented or lightweight models, where the lower cost and simpler design of drum brakes can be advantageous. Additionally, drum brakes may be found on the rear wheels of some heavy-duty vehicles, such as trucks and trailers, where their ability to handle higher loads can be beneficial.
However, as technology continues to advance and the cost of disc brake systems decreases, the use of drum brakes in modern vehicles is expected to continue declining, with disc brakes becoming the predominant choice for both front and rear wheel applications.
Why does Toyota still use drum brakes?
Fans of other trucks point and laugh. However, there are a few good reasons why Tacomas have drums: Cost: Drum brakes are cheaper to manufacture than disc brakes, and Toyota passes the savings along to its customers. On the Tacoma (and most unloaded pickups), the front brakes do 70%-80% of the braking.
What was the last year for drum brakes?
In the 80s nearly every car had rear drum brakes, that phased out in the early 90s or so. Only the very cheapest cars had drums past that timeframe.
Why do new cars still come with rear drum brakes?
One of the primary reasons rear drum brakes remain popular is their cost efficiency. Drum brakes are less expensive to manufacture and install compared to disc brakes. For automakers, this means they can keep production costs down and offer more competitively priced vehicles.
Why don't cars use drum brakes?
Because the mechanisms of a drumbrake are enclosed in the drum, which itself is not very good at dissipating hear into the air, they tend to have a lower capacity to stop over long or aggresive braking cycles.
What is the main problem with drum brakes?
Drum brake disadvantages
Excessive heating can happen due to heavy braking, which then can cause the drum to distort, and thus cause vibration under braking. Under hard braking, the diameter of the drum increases slightly due to thermal expansion, the driver must press the brake pedal farther.
What was the last car to use drum brakes?
In the United States, the Jeep CJ-5 (manufactured by AM General) was the final automobile (produced for the United States Postal Service) to use front drum brakes when it was phased out in 1986.
What is better, disc or drum brakes?
Drum brakes use an enclosed drum mechanism, while disc brakes use exposed brake discs and callipers. Also, compared to drum brakes, disc brakes generally offer better braking performance, heat dissipation, and consistency.
Why did we stop using drum brakes?
The design of drum brakes results in less precise braking control, with a tendency to lock up under hard braking.
Do drum brakes stop better than disc?
Improved Stopping Distance – With disc brakes, stopping distance can be 17–33% shorter than drum brakes, depending on the speed of the vehicle.
