CDL Combination Vehicles TestCombination Vehicle Air BrakesEasy
You are making a full stop in a combination vehicle equipped with ABS. The road surface is wet and slippery. What is the most effective braking technique to maintain steering control?
- AApply firm, steady pressure to the brake pedal.
- BPump the brake pedal lightly to avoid wheel lock-up.
- CDownshift aggressively and use engine braking only.
- DApply the trailer hand valve first, then the foot brake.
Show answer & explanationAnswer & explanation
Correct answer: A. Apply firm, steady pressure to the brake pedal.
With ABS, the system automatically modulates brake pressure to prevent wheel lock-up. The most effective technique is to apply firm, steady pressure to the brake pedal and let the ABS do its job to maintain steering control.
Why the other options are wrong
- B. Pumping the brakes is for vehicles without ABS; it interferes with ABS function.
- C. Relying solely on engine braking may not provide sufficient stopping power in an emergency and can cause skidding on slippery surfaces.
- D. Applying the trailer hand valve first can cause the trailer to skid or jackknife, especially on slippery roads.
ABS Braking Technique
When driving a combination vehicle with Anti-lock Braking Systems (ABS), the proper technique for emergency braking is to apply firm, steady pressure to the foot brake pedal.
- ABS prevents wheel lock-up automatically.
- Do not pump the brakes with ABS.
- Allows the driver to maintain steering control.
- Works on all axles with ABS.
Memory trick: ABS is your steady friend, press the pedal, to the very end.