What indicates a vehicle should be rejected concerning the brake pedal reserve test?

The criterion for rejecting a vehicle concerning the brake pedal reserve test is if the pedal moves toward the toe board when pressure is applied. This indicates that there is insufficient reserve or clearance for the brake pedal, which can be a sign of potential issues such as low brake fluid, air in the brake lines, or worn brake components. A pedal that moves too far forward signals that the braking system may not function effectively in an emergency situation, hence compromising the vehicle's safety.

In contrast, if the pedal remains firm with no movement, it demonstrates that the brake system is keeping its position under pressure, which is a positive sign. A pedal that bounces back quickly after release suggests good system response, indicating that the brakes are functioning properly and are not stuck or malfunctioning. Finally, while the pedal must move with full pressure, it should not exhibit significant movement that would indicate a failure. Therefore, the correct indication for a rejection in this test is the movement of the pedal towards the toe board.