RIDEX 277W0005 Wheel Brake Cylinder

VW drum brakes, found on some VW models particularly for the rear wheels, are a type of braking system that utilizes friction between rotating parts to slow down the car. Here’s a breakdown of how they work in your VW:

• Components:

  • Drum: A rotating cylindrical metal part that houses the braking mechanism.
  • Brake shoes: Two curved, horseshoe-shaped components lined with friction material (like brake pads) positioned inside the drum.
  • Wheel hub: The drum is usually attached to the wheel hub, which allows the wheel to rotate.
  • Springs: Keep the brake shoes retracted when not braking and ensure they make contact with the drum upon braking.
  • Wheel cylinder: A hydraulic component that pushes the brake shoes outward when you press the brake pedal.

• The Braking Process:

  1. You press the brake pedal.
  2. Brake fluid from the master cylinder travels through brake lines to the wheel cylinder in the rear drum brake.
  3. The wheel cylinder’s piston is pushed out by the hydraulic pressure.
  4. The piston presses the brake shoes outward against the inner surface of the rotating drum.
  5. Friction between the brake shoes and the drum lining converts the car’s kinetic energy (motion) into heat, slowing down the wheel.
  6. Springs retract the brake shoes when you release the brake pedal, allowing the wheel to resume normal rotation.

• Advantages:

  • Simpler design compared to disc brakes.
  • Potentially less expensive to manufacture and maintain.
  • Effective in protecting the braking mechanism from dirt and debris (especially relevant for rear wheels).

• Disadvantages:

  • Generally less effective at dissipating heat compared to disc brakes, leading to potential fading during sustained braking.
  • Can be more prone to moisture or water affecting braking performance.
  • Not as readily visible for wear and tear inspection compared to disc brakes.

In essence: VW drum brakes utilize friction between internal brake shoes and a rotating drum to slow down the car, particularly on rear wheels in some models. While simpler in design, they may not perform as well as disc brakes in all situations.