You are doing a pre-trip inspection on a set of doubles or triples. How should the drain valve on the converter dolly's air tank be set?

Answer options

Why

The drain valve on a dolly's air tank must be closed so the tank holds the air the dolly brakes need. During the same walkaround, the shut-off valves should be open at the rear of the front trailers and closed at the rear of the last one.

About this question

Topic: Doubles and triples   License: CDL

Part of these practice sets:

• Inspecting Doubles and Triples

Where it applies: Asked in every state.

Practice the whole set

This question is part of Inspecting Doubles and Triples (15 questions). Take the full set and check your score.

More questions from Inspecting Doubles and Triples

• When you inspect a doubles or triples rig on your walk-around, in what state should you find the air tank drain valves on the converter dolly and the pintle hook?
• What is the reason a rig with two or three trailers needs a more careful inspection than one pulling a single semitrailer?
• To test the trailer brakes, you apply the hand valve and open the valve on the service line at the very rear of the combination. What sound should you hear?
• How do you confirm that air is reaching every trailer in a double or triple combination?
• On a walk-around inspection, what should be true of every landing gear?
• You are inspecting a converter dolly. What must be true of its pintle hook connection?
• Which of these is a key check when you inspect a double or triple rig?
• In a double or triple combination, how should you set the shut-off valves located at the back of the rearmost trailer?