What prevents the shoes from shifting during operation?

The anchor pin plays a crucial role in maintaining the stability of brake shoes during operation. In drum brake systems, the brake shoes are positioned against the drum when the brakes are applied, creating friction to slow down or stop the vehicle. The anchor pin secures the shoes at a fixed point, preventing any unwanted movement or shifting as the shoes expand due to hydraulic pressure from the master cylinder during braking. This secure positioning is essential for effective braking performance, ensuring that the shoes press evenly against the drum, thereby maximizing friction and effectiveness in stopping the vehicle.

The other components, such as the master cylinder, brake fluid, and brake pads, serve different functions. The master cylinder generates hydraulic pressure, brake fluid serves as the medium to transmit that pressure, and brake pads are used in disc braking systems rather than drum brakes. These components do not directly prevent the shoes from shifting; instead, they contribute to the overall braking process.