Practice question

Why must intermediate shut-off valves be open?

To carry air to following trailer brakes
To drain tanks constantly
To unload cargo
To lock the pintle hook

Answer: A — To carry air to following trailer brakes

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

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