CDL · Doubles and triples
Besides the checks you would make on any combination vehicle, what else must you inspect on doubles or triples?
Correct answer: Each trailer's air brakes, every converter dolly, and the shut-off valves.
Answer options
- AEach trailer's air brakes, every converter dolly, and the shut-off valves. Correct
- BThe overall look of the trailers and whether the cab radio works.
- COnly the fifth wheel, the landing gear, and the lights.
Why
After the standard combination-vehicle checks, verify that the shut-off valves at the back of every trailer are open, except on the last trailer, where they must be closed. Also inspect each converter dolly and confirm that air reaches the brakes on all trailers.
About this question
Topic: Doubles and triples License: CDL
Part of these practice sets:
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.
Practice Inspecting Doubles and TriplesMore questions from Inspecting Doubles and Triples
- At a roadside inspection, an inspector checks the converter dolly between the trailers of a standard double. Which defect would make the inspector take the dolly out of service?
- Federal rules require antilock brakes (ABS) on converter dollies manufactured from which month and year onward?
- How can you check that air is actually getting all the way to the second trailer?
- What tells you that a converter dolly is fitted with antilock brakes (ABS)?
- Which lamp is required on a converter dolly that has an antilock braking system (ABS)?
- In a double or triple combination, how should you set the shut-off valves located at the back of the rearmost trailer?
- Which of these is a key check when you inspect a double or triple rig?
- You are inspecting a converter dolly. What must be true of its pintle hook connection?
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