Home › CDL Practice Tests › Air Brakes Questions › Question 82
Why is fanning the brakes (rapidly pumping the pedal) dangerous when air pressure is already low?
- A.Fanning charges the tanks more quickly
- B.Fanning only affects the trailer brakes
- C.Each application spends stored air faster than a weak compressor can replace it, hastening total loss and spring application
- D.Fanning is dangerous only when parked
Correct answer
C. Each application spends stored air faster than a weak compressor can replace it, hastening total loss and spring application
Why
Every pedal stroke moves a volume of air from the tanks to the chambers and out the exhaust. On a low system that spending spree is the fastest route to having no service brakes at all.
Manual topic: Air Brakes - Air Leakage and Brake Tests · From the Air Brakes practice bank (AB-082).