BRAKES: How They Work | Science Garage

Introduction

In this tutorial, we will explore the evolution of braking systems in vehicles, focusing on drum brakes and disk brakes. Understanding how these systems work and their differences is essential for anyone interested in automotive mechanics or car maintenance.

Chapter 1: Understanding Drum Brakes

• Overview of Drum Brakes

  • Drum brakes became prevalent in early automobiles to assist with braking.
  • They consist of a drum attached to the wheel, with heat-resistant pads inside.

• How They Work

  • When the brake pedal is pressed:
    • The pads are squeezed against the drum.
    • The friction slows the drum, which in turn stops the wheel.

• Challenges with Drum Brakes

  • Early models used cables and pulleys for operation, which required regular maintenance and were prone to snapping.
  • If any component was misaligned, it could lead to uneven braking pressure across the wheels, creating unsafe driving conditions.

Chapter 2: Transition to Hydraulic Brakes

• Introduction of Hydraulic Brakes

  • Hydraulic brakes use pressurized fluid instead of cables.
  • Pressing the pedal pushes a plunger in the master cylinder, distributing pressure evenly to all wheels.

• Advantages of Hydraulic Brakes

  • Require less pedal pressure to be effective.
  • Less prone to maintenance issues compared to mechanical lines.
  • By the 1950s, hydraulic brakes became the standard in cars.

Chapter 3: The Move to Disk Brakes

• Limitations of Drum Brakes

  • Drum brakes can overheat under intense conditions, reducing their effectiveness.
  • High temperatures can prevent the conversion of motion energy into heat.

• Improving Braking Systems with Disk Brakes

  • Disk brakes were developed to address the drawbacks of drum brakes:
    • Increased friction is achieved by using better materials for the pads.
    • More pressure can be applied by squeezing inward instead of pushing outward.
    • Larger surface areas on disk brakes enhance friction and cooling.

• How Disk Brakes Work

  • The rotor (disk) is attached to the wheel and sits inside a caliper.
  • When brakes are applied, the caliper squeezes the brake pads against the rotor, slowing the wheel.
  • Disk brakes cool better because they are exposed to air, preventing overheating.

Chapter 4: Disk Brake Innovations

• Racing Origins

  • The first use of disk brakes was in Formula 1 racing in 1951.
  • Citroen introduced them to production cars in 1955.

• Modern Applications

  • Despite being more expensive, disk brakes became necessary as cars became faster.
  • Although still used in many vehicles, drum brakes remain common in lighter or entry-level models due to their cost-effectiveness.

• Design Enhancements for Better Heat Dissipation

  • Rotors may have:
    • Gaps to let air in.
    • Fins to improve airflow.
    • Holes for enhanced cooling.

Chapter 5: Brake Pads and Maintenance

• Understanding Brake Pad Materials

  • Most pads are semi-metallic, combining synthetic materials with metals for durability.
  • Race pads are often made from sintered steel for high-temperature performance.

• Recognizing Brake Warning Signs

  • Squealing brakes can indicate that pads are worn down.
  • Manufacturers often include indicators that make noise when pads are nearly depleted.
  • If brakes squeal, investigate for misalignment or debris.

Conclusion

Understanding the evolution and mechanics of braking systems is crucial for vehicle safety. From the early drum brakes to the modern disk brakes, each advancement has aimed to improve efficiency and safety. Regular maintenance and awareness of warning signs can ensure your braking system remains effective. For further exploration of automotive modifications or safety tips, consider following additional resources or tutorials on car maintenance.