CDL Combination Test (2024) - FREE Hawaii Practice Test

1. Before driving a vehicle with a dual air brake system, you should allow time for the air compressor to build up a minimum of ____ pressure in both the primary and secondary systems.

150 psi
50 psi
100 psi

2. When backing a tractor under a trailer, you should:

back at an angle.
always use the lowest reverse gear.
stop before when the kingpin is locked into the fifth wheel.

3. When you drive a tractor-trailer combination with ABS, you should:

apply the trailer hand brake whe braking.
brake as you always have.
pump the brakes.

4. When you make a quick lane change, the crack-the-whip effect can turn the trailer over. The crack-the-whip effect is caused by:

rearward amplification.
the rear trailer of a triple.
strong wind.

5. If loose or missing, _______ may cause movement between the frame and fifth wheel assembly.

electric connectors
locking pins
mounting bolts

6. You supply air to the trailer brake system by:

connecting the tractor service air line to the trailer service glad hand.
plugging the electrical cord into the trailer.
pushing in the trailer air supply knob.

7. A high center of gravity means:

a rollover is less likely.
you'll have better traction.
you are more likely to tip over.

8. Combination vehicles have __ air lines.

2
3
1

9. To prevent rollover, drivers of combination vehicles should:

brake while turning.
keep the cargo as close to the ground as possible.
keep the load is to one side.

10. A burning tire must be:

covered with cloth.
cooled with water.
immediately removed from the vehicle.

Number of questions:	20
Correct answers to pass:	16
Passing score:	80%

COMBINATION PRACTICE TEST - HI CDL

HI Combination Test