While travelling downhill, you notice that each time you want to brake, you must press the brake pedal farther down than the last time to achieve the same braking force. What could be causing this?
- A too-slow air compressor
- A faulty air compressor governor
- A jammed foot brake pedal
- Brake fade ✓
Answer: D. Brake fade
The likely cause is brake fade.
Why this is the answer
The handbook defines brake fade as brakes that stop working properly because they are overheated, so the vehicle takes longer to stop or may not stop at all if speed is not properly controlled. It also says frequent use of the service brakes heats them and reduces their stopping ability. Needing to push the pedal farther each time for the same braking force fits that loss of braking performance as heat builds up on a downhill.
Why the other answers are wrong
- A. A too-slow air compressor — A too-slow air compressor is not mentioned in the passages as a cause of this progressive loss of braking force.
- B. A faulty air compressor governor — A faulty air compressor governor is not described in the passages as producing this symptom.
- C. A jammed foot brake pedal — A jammed foot brake pedal would point to a pedal that will not move freely, not one that needs progressively more travel to get the same braking.
Remember it
When braking feels weaker on a downgrade, think heat buildup and brake fade.