Final answer:
Neither Technician A nor B is entirely correct as their statements do not align with standard expectations for parking brake functionality, which is to secure a parked vehicle rather than stopping a moving one within certain distances or on specific grades.
Step-by-step explanation:
The student asked whether Technician A, who says the parking brake should hold the vehicle on a 30 percent grade in both directions, or Technician B, who says the parking brake must be able to stop a vehicle moving 5 mph within 100 feet, is correct. Neither of these statements is entirely accurate based on standard regulatory expectations
The primary function of the parking brake is to secure a vehicle when it is parked, preventing it from rolling away. This typically involves holding the vehicle stationary on a hill, but there's no universally specified grade percentage for this test.
Additionally, the use of the parking brake to stop a moving vehicle is not its intended design, and specifics such as stopping a car within 100 feet at 5 mph are neither standard performance metrics. It's generally designed for emergency use and will not have the same efficacy as service brakes for stopping a moving vehicle.