Home › CDL Practice Tests › Air Brakes Questions › Question 215
What does an ABS lamp that comes on and stays on while driving at speed tell you about the service brakes themselves?
- A.The service brake chambers have all ruptured
- B.There is no air left in any tank
- C.The parking brake has been destroyed
- D.The foundation service brakes should still stop the vehicle, but without antilock protection at the affected wheels
Correct answer
D. The foundation service brakes should still stop the vehicle, but without antilock protection at the affected wheels
Why
ABS is an added control layer on top of the normal air brake system, and its failure removes the layer rather than the foundation brakes. The practical change is greater lockup and skid risk in hard stops, especially on slippery surfaces.
Manual topic: Air Brakes - ABS · From the Air Brakes practice bank (AB-215).