Michigan State Brakes Certification Practice Exam 2025 - Free Brakes Certification Practice Questions and Study Guide

A corroded master cylinder bore is indeed the least likely cause of one brake dragging because this issue primarily affects the hydraulic system's ability to generate or maintain pressure for the brake components. If the master cylinder is corroded, it may lead to poor braking performance overall or a complete loss of braking function, but it does not typically cause one specific brake to drag.

In contrast, a stuck rubber brake line could impede fluid flow and create uneven pressure, leading to dragging on one side. Similarly, a malfunctioning brake caliper could cause sticking or binding of the brake pads to the rotor, resulting in dragging. Lastly, a collapsed flexible brake hose can allow fluid to pass into the brakes but not return properly, which may cause the brakes to remain engaged on one wheel. Thus, while all these components can affect brake operation, a corroded master cylinder bore is less directly related to the phenomenon of dragging brakes specifically on one side.