Louisiana Commercial
Driver License Air Brakes
Exam Practice Questions
And Correct Answers
(Verified Answers) Plus
Rationales 2027 Q&A
How do you supply air to the trailer tanks? - correct answer 100%-
✔✔Push in the trailer air supply valve.
What happens when there is a loss of air pressure in the emergency line? -
correct answer 100%-✔✔Trailer emergency brakes come on.
, When does a tractor-trailer require the shortest stopping distance? - correct
answer 100%-✔✔When it is empty.
What is true about combination-vehicle braking? - correct answer 100%-
✔✔Bobtail tractors can take longer to stop than fully loaded combinations.
What should you do if you can't make a right turn without swinging into another
lane? - correct answer 100%-✔✔Don't make that turn; find another place
to turn.
What causes the tractor protection valve to close and trailer emergency brakes to
come on? - correct answer 100%-✔✔A major leak in the emergency line.
Which combination follows the widest path when turning? - correct answer
100%-✔✔3-axle tractor towing two 27-foot trailers.
What should you do if your vehicle is stuck on a railroad crossing? - correct
answer 100%-✔✔Get out and move away from the tracks.
Where are shut-off valves located on trailers used to tow other trailers? -
correct answer 100%-✔✔At the back of the trailer.
Before backing under a trailer, what should you ensure? - correct answer
100%-✔✔The trailer brakes are locked.
Driver License Air Brakes
Exam Practice Questions
And Correct Answers
(Verified Answers) Plus
Rationales 2027 Q&A
How do you supply air to the trailer tanks? - correct answer 100%-
✔✔Push in the trailer air supply valve.
What happens when there is a loss of air pressure in the emergency line? -
correct answer 100%-✔✔Trailer emergency brakes come on.
, When does a tractor-trailer require the shortest stopping distance? - correct
answer 100%-✔✔When it is empty.
What is true about combination-vehicle braking? - correct answer 100%-
✔✔Bobtail tractors can take longer to stop than fully loaded combinations.
What should you do if you can't make a right turn without swinging into another
lane? - correct answer 100%-✔✔Don't make that turn; find another place
to turn.
What causes the tractor protection valve to close and trailer emergency brakes to
come on? - correct answer 100%-✔✔A major leak in the emergency line.
Which combination follows the widest path when turning? - correct answer
100%-✔✔3-axle tractor towing two 27-foot trailers.
What should you do if your vehicle is stuck on a railroad crossing? - correct
answer 100%-✔✔Get out and move away from the tracks.
Where are shut-off valves located on trailers used to tow other trailers? -
correct answer 100%-✔✔At the back of the trailer.
Before backing under a trailer, what should you ensure? - correct answer
100%-✔✔The trailer brakes are locked.
