FREE Maine CDL Doubles Triples Practice Test (2024)

1. You should test the coupling by:

pulling against the pin of the second semitrailer.
locking the pintle hook.
applying the parking brakes so the rig will not move.

2. If your brakes fail on a steep mountain downgrade, you should:

slow down until your vehicle comes to a complete stop.
stay on the road and keep looking for the next available escape ramp.
decide what to do as soon as you know your brakes do not work.

3. To prevent a rollover, the driver should:

make quick lane changes if possible.
drive slowly around corners, on ramps, and off ramps.
drive on the shoulder if possible.

4. You should flash your brake lights to warn drivers behind you when:

you see a hazard that will require slowing down.
you see a bus stops in the roadway ahead to unload passengers.
All of the above.

5. When inspecting the coupling, make sure the fifth-wheel jaws have closed around the:

6. When you push in the red trailer air supply knob, this will:

open the emergency line shut-off valve at the rear of the last trailer.
supply air to the emergency supply lines.
disconnect the air lines from the trailer.

7. Which of the following statements is true?

There is no way that short circuits due to damaged insulation can cause a vehicle fire.
Poor cargo ventilation is a common cause of fire.
Carrying a properly charged and rated fire extinguisher will help prevent fires.

8. If the safety relief valve in the air brake system releases air:

the valve is fully operational.
something is wrong.
this will supply more power to the brakes.

9. Alcohol:

10. Combination vehicles have __ air lines.

MAINE CDL DOUBLES TRIPLES PRACTICE TEST