Practice question

What is the safest response if you discover the rear trailer shut-off valves are open during a walkaround?

  1. Close the rear valves and recheck air pressure and brake operation
  2. Leave them open because more air is better
  3. Drive only at low speed
  4. Disconnect the rear trailer electrical cord

Answer: A — Close the rear valves and recheck air pressure and brake operation

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

Practice more: PA CDL Doubles Triples Practice Questions - Pennsylvania CDL Doubles and Triples Endorsement Test Exam →