CDL COMBINATION VEHICLES III
COMPREHENSIVE STUDY SHEET 2026 SOLVED
QUESTIONS PREMIUM BUNDLE
◉ What colors are used for the air lines on a combination vehicle?
Answer: The emergency line is red; the service line is blue.
◉ What should you do if the brakes did not release when you
pushed the trailer air supply valve?
Answer: Check the air line connections.
◉ How much space should you leave between your vehicle and the
vehicle ahead under good driving conditions?
Answer: At least one second of space for every 10 feet of your
vehicle's length.
◉ What do semi-trailers made before 1975 equipped with air brakes
often lack?
Answer: They often do not have spring brakes.
◉ Which trailer is most likely to turn over when turning suddenly
while pulling doubles?
, Answer: The rear trailer is twice as likely to turn over as the tractor.
◉ What are the other names for the service air line?
Answer: Control line and signal line.
◉ What should you do after coupling the trailer?
Answer: Start to raise the landing gear by using low gear.
◉ What gear should the tractor engine be in after uncoupling the
trailer?
Answer: Neutral.
◉ What does the trailer air supply control do?
Answer: It supplies air to the trailer system, shuts the air off, and
applies the trailer emergency brakes.
◉ What should the red air supply control knob do when testing the
tractor protection valve?
Answer: It should go into the emergency position.
◉ What must be present at the extreme end of a load extending four
feet or more beyond the rear of the vehicle at night?
Answer: Red lights.
COMPREHENSIVE STUDY SHEET 2026 SOLVED
QUESTIONS PREMIUM BUNDLE
◉ What colors are used for the air lines on a combination vehicle?
Answer: The emergency line is red; the service line is blue.
◉ What should you do if the brakes did not release when you
pushed the trailer air supply valve?
Answer: Check the air line connections.
◉ How much space should you leave between your vehicle and the
vehicle ahead under good driving conditions?
Answer: At least one second of space for every 10 feet of your
vehicle's length.
◉ What do semi-trailers made before 1975 equipped with air brakes
often lack?
Answer: They often do not have spring brakes.
◉ Which trailer is most likely to turn over when turning suddenly
while pulling doubles?
, Answer: The rear trailer is twice as likely to turn over as the tractor.
◉ What are the other names for the service air line?
Answer: Control line and signal line.
◉ What should you do after coupling the trailer?
Answer: Start to raise the landing gear by using low gear.
◉ What gear should the tractor engine be in after uncoupling the
trailer?
Answer: Neutral.
◉ What does the trailer air supply control do?
Answer: It supplies air to the trailer system, shuts the air off, and
applies the trailer emergency brakes.
◉ What should the red air supply control knob do when testing the
tractor protection valve?
Answer: It should go into the emergency position.
◉ What must be present at the extreme end of a load extending four
feet or more beyond the rear of the vehicle at night?
Answer: Red lights.
