CDL - Combination Vehicle Practice Test
Exam Questions And Answers
A tractor with a(n) ________ trailer requires the shortest amount of
stopping distance .
1. empty
2. fully loaded
3. lightly loaded -
correct answer ✅fully loaded
The air leakage rate for a combination vehicle ( engine off, brakes
on) should not be more than _____ psi per minute .
1. 4
2. 6
3. 2 -
correct answer ✅4
If you do not do the final air brake check for air leaks and fix them
before driving,
1. you could lose your brakes while driving
2. your fuel usage will increase
3. tire pressure will drop -
correct answer ✅you could lose your brakes while driving
, CDL - Combination Vehicle Practice Test
Exam Questions And Answers
Which part of the kingpin should the locking jaws close around? -
correct answer ✅The shank
Glad hands are used to connect the ....
1. kingpin from the trailer to the locking jaws of the fifth wheel
2. electrical lines from the tractor to the trailer
3. service and emergency air lines from the truck or tractor to the
trailer -
correct answer ✅service and emergency air lines from the truck or
tractor to the trailer
Trucks roll over more easily when fully loaded and are
1. ten times more likely to roll over in a crash than empty rigs
2. five times more likely to roll over in a crash than empty rigs
3. two times more likely to roll over in a crash than empty rigs -
correct answer ✅ten times more likely to roll over in a crash than
empty rigs
In general, the higher your trucks center of gravity, the ...
1. easier it is to turn over
2. more stable it is when turning
Exam Questions And Answers
A tractor with a(n) ________ trailer requires the shortest amount of
stopping distance .
1. empty
2. fully loaded
3. lightly loaded -
correct answer ✅fully loaded
The air leakage rate for a combination vehicle ( engine off, brakes
on) should not be more than _____ psi per minute .
1. 4
2. 6
3. 2 -
correct answer ✅4
If you do not do the final air brake check for air leaks and fix them
before driving,
1. you could lose your brakes while driving
2. your fuel usage will increase
3. tire pressure will drop -
correct answer ✅you could lose your brakes while driving
, CDL - Combination Vehicle Practice Test
Exam Questions And Answers
Which part of the kingpin should the locking jaws close around? -
correct answer ✅The shank
Glad hands are used to connect the ....
1. kingpin from the trailer to the locking jaws of the fifth wheel
2. electrical lines from the tractor to the trailer
3. service and emergency air lines from the truck or tractor to the
trailer -
correct answer ✅service and emergency air lines from the truck or
tractor to the trailer
Trucks roll over more easily when fully loaded and are
1. ten times more likely to roll over in a crash than empty rigs
2. five times more likely to roll over in a crash than empty rigs
3. two times more likely to roll over in a crash than empty rigs -
correct answer ✅ten times more likely to roll over in a crash than
empty rigs
In general, the higher your trucks center of gravity, the ...
1. easier it is to turn over
2. more stable it is when turning
