Automotive Service Excellence (ASE) Brakes Certification Practice Exam 2025 – Comprehensive All-in-One Guide to Exam Success!

Technician A is correct in asserting that disc brake pads often require a higher application pressure compared to drum brake shoes. This is primarily because disc brakes typically have a different design and utilize a caliper that must exert force to clamp the pads against the rotor. The amount of pressure required can be influenced by factors such as the materials of the pads and rotors and the overall design of the braking system. Consequently, disc brake systems often account for these variables by requiring increased pressure to achieve effective braking performance.

Technician B is also correct; the caliper piston retracts due to the design of the brake system, which often includes a square-cut O-ring. This O-ring is part of the sealing mechanism that maintains hydraulic pressure within the caliper when the brakes are applied. After the brake pedal is released, the hydraulic pressure is relieved, allowing the inherent spring tension or the compression of the O-ring to aid in retracting the piston. This design ensures that the brake pads maintain a slight gap from the rotor when not engaged, preventing unnecessary wear.

Both technicians provide accurate information regarding their respective statements about the functioning of disc brake systems.