Practice question

What is the danger of using the trailer hand valve as a parking brake?

  1. Air can leak out and release the trailer brakes, allowing the trailer to roll
  2. The trailer hand valve cannot supply enough pressure
  3. The kingpin will disengage
  4. The fifth wheel will tilt

Answer: A — Air can leak out and release the trailer brakes, allowing the trailer to roll

The correct answer is shown above. Try the full quiz for additional practice.

Practice more: Washington CDL Combination Practice Questions - Washington CDL Combination Vehicles Test Exam →