CDL Class A Combination Vehicle Test

CDL CLASS A COMBINATION VEHICLE
TEST 100% SOLVED QUESTIONS AND
ANSWERS

x The trailer should be lowered so that...

A) the trailer is far above the fifth wheel

B) the tractor strikes the nose of the trailer

C) you can use the landing gear to make any adjustments

D) it's raised slightly when the tractor's backed under it - D

Which one of the following is controlled by the foot brake?

A) the service air line

B) the emergency air line

C) the shut off valve

D) the hose coupler - A

When you inspect the coupling, check to ensure that...

A) there's a little slack in the air lines

B) there's no slack in the air lines

C) the landing gear handle is hanging free

D) the electrical cable is unplugged - A

Air lines on a combination vehicle are often colored to keep them from getting mixed up. The emergency
line is ____; the service line is____.

A) Red, blue

B) Blue, red

C) Black, yellow

D) Depends on the type of trailer - A

After you supply air to the trailer, make sure the air lines are not crossed and the trailer brakes are
working. This is done by:

A) applying and releasing the trailer brakes and listening for brake sounds