What does "brake fade" refer to?

Brake fade refers to the reduction of braking effectiveness due to overheating, which typically occurs when the brakes are used excessively or under extreme conditions. As brakes heat up, the friction material on the brake pads can lose its effectiveness, leading to a decrease in the ability to stop the vehicle effectively. This phenomenon is particularly common in situations such as prolonged descents or repeated hard braking, where heat builds up quickly and can impair the functionality of both the brake pads and the discs. Understanding brake fade is crucial for ensuring safe vehicle operation, as a slight fade can escalate to a complete loss of braking power if not managed properly.

The other options describe various aspects of brake system maintenance or performance issues but do not accurately capture the specific definition of brake fade. The accumulation of dirt on brake pads, for instance, may lead to decreased performance but is not the same as the heat-related issue defined by brake fade. Similarly, a temporary loss of brake fluid pressure may affect braking but is not tied to heat accumulation, and the gradual wear of brake discs pertains to normal wear and tear rather than a specific malfunction like brake fade.