Summary CDL Class A Combination Vehicle Test Questions and Answers

CDL Class A Combination Vehicle Test
Questions and Answers
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 -
Correct Answer ✅ 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 - Correct Answer ✅ 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 - Correct Answer ✅ A

, CDL Class A Combination Vehicle Test
Questions and Answers
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 - Correct Answer ✅ 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

B) lifting the brake pedals

C) turning on the parking brakes from the cab

D) releasing the tractor brakes - Correct Answer ✅ A



You have coupled with a semi trailer. In what position should
you put the front trailer supports before driving away?