Combination Vehicles Practice Test Flashcards

When backing a combination vehicle, why is it always better to back to the driver's side?

Answer: You can watch the rear of your trailer through the side window

Backing to the driver's side lets you see the trailer's position by looking out the side window, while sight-side backing avoids blind-side guesswork.

What is offtracking in a combination vehicle?

Answer: When the rear wheels follow a tighter path than the front wheels in a turn

Offtracking (cheating) occurs because the rear wheels follow a different, tighter path than the front wheels during a turn, so you must swing wide as needed.

To avoid hitting an object on the right when turning a corner with a long combination vehicle, you should:

Answer: Turn wide as you start the turn

Keep the rear of the vehicle close to the curb and turn wide only as you complete the turn, so you do not swing into traffic or lose sight of the rear.

What does a converter dolly with a single axle and no brakes of its own rely on for stopping?

Answer: The brakes of the trailers it connects

A converter dolly is used to connect trailers and its braking is integrated through the air lines of the trailers it couples.

Which trailer should be loaded first and placed closest to the tractor in a doubles combination?

Answer: The heaviest trailer

The heavier trailer should be in front (closest to the tractor) to improve handling and reduce trailer sway.

When uncoupling, before you disconnect the fifth wheel you should:

Answer: Release the trailer air supply and lower the landing gear

Lower the landing gear until it supports the trailer and set the trailer brakes before pulling the fifth-wheel release handle.

A 'kingpin' is the part of a combination vehicle that:

Answer: Locks into the fifth wheel of the tractor

The kingpin is the steel pin on the trailer that locks into the fifth-wheel jaws of the tractor.