Why should you never use the brake pedal to hold your vehicle on a hill when the spring brakes are engaged?
a.It wastes fuel
b.Air pressure could leak away, releasing the service brakes and causing the vehicle to roll
c.It causes excessive tire wear
d.It damages the air compressor
Explanation
If you use the brake pedal (service brakes) to hold your vehicle and the air leaks away, you will lose braking. Spring brakes, on the other hand, are applied mechanically by springs and do not depend on air pressure to remain engaged.