CDL · 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?
Correct answer: Drain valves closed, pintle hook latched.
Answer options
- ADrain valves closed, pintle hook latched. Correct
- BDrain valves open, pintle hook released.
- CDrain valves open, pintle hook latched.
Why
The dolly's air tank drain valves must be shut, or the tank will leak the air its brakes depend on. The pintle hook must be latched so the dolly's eye cannot slip out and let a trailer break away.
About this question
Topic: Doubles and triples License: CDL
Part of these practice sets:
Where it applies: Asked in every state.
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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
- What is the reason a rig with two or three trailers needs a more careful inspection than one pulling a single semitrailer?
- 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?
- 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?
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