What is the minimum total pedal reserve that must remain to pass the pedal reserve test?

The correct answer indicates that a minimum of one-third of the total pedal reserve must remain to successfully pass the pedal reserve test. This requirement is critical for vehicle safety, particularly regarding the braking system's functionality.

Maintaining at least one-third of the total pedal reserve ensures that there is sufficient hydraulic pressure in the brake system. This pressure is essential for effective braking performance and helps to prevent brake failure. If the pedal reserve is too low, the brakes might not engage or respond effectively in a critical situation, presenting a safety hazard.

A higher percentage of reserve, like one-half or two-thirds, would be overly cautious and not a requirement. The one-third threshold balances the necessity for safety with the understanding that, in normal operation, maintaining robust performance is usually achievable while still allowing for some wear and tear. Therefore, meeting or exceeding this minimum reserve is crucial for the vehicle to be deemed safe and roadworthy during inspections.