CDL - Combination Vehicle Practice Test Questions with
Answers Graded A+
A tractor with a(n) ________ trailer requires the than empty rigs - ANSWER -ten times more
shortest amount of stopping distance . likely to roll over in a crash than empty rigs
1. empty
2. fully loaded
3. lightly loaded - ANSWER -fully loaded In general, the higher your trucks center of
gravity, the ...
1. easier it is to turn over
The air leakage rate for a combination vehicle ( 2. more stable it is when turning
engine off, brakes on) should not be more than 3. easier it is to turn around corners -
_____ psi per minute . ANSWER -easier it is to turn over
1. 4
2. 6
3. 2 - ANSWER -4 You are driving a combination vehicle when the
trailer breaks away, pulling apart both air lines.
You would expect the trailer brakes to come on
If you do not do the final air brake check for air and ...
leaks and fix them before driving, 1. the tractor to lose all air pressure
1. you could lose your brakes while driving 2. the tractor protection valve to close
2. your fuel usage will increase 3. the trailer supply valve to stay open -
3. tire pressure will drop - ANSWER -you ANSWER -the tractor protection valve to
could lose your brakes while driving close
Which part of the kingpin should the locking jaws When you drive a set of doubles, which shut-off
close around? - ANSWER -The shank valve must be closed in the last trailer?
1. Middle section
2. front section
Glad hands are used to connect the .... 3. back section - ANSWER -back section
1. kingpin from the trailer to the locking jaws of
the fifth wheel
2. electrical lines from the tractor to the trailer The fifth wheel locking lever is not locked after
3. service and emergency air lines from the truck the jaws close around the kingpin. This means
or tractor to the trailer - ANSWER -service that...
and emergency air lines from the truck or tractor 1. the parking lock is off and you may drive away
to the trailer 2. the trailer will not swivel on the fifth wheel
3. the coupling is not right and should be fixed
before you drive the coupled unit -
Trucks roll over more easily when fully loaded ANSWER -the coupling is not right and
and are should be fixed before you drive the coupled unit
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 What gear should the tractor engine be in after
than empty rigs you uncouple the trailer and are inspecting the
3. two times more likely to roll over in a crash trailer?
1/4
Answers Graded A+
A tractor with a(n) ________ trailer requires the than empty rigs - ANSWER -ten times more
shortest amount of stopping distance . likely to roll over in a crash than empty rigs
1. empty
2. fully loaded
3. lightly loaded - ANSWER -fully loaded In general, the higher your trucks center of
gravity, the ...
1. easier it is to turn over
The air leakage rate for a combination vehicle ( 2. more stable it is when turning
engine off, brakes on) should not be more than 3. easier it is to turn around corners -
_____ psi per minute . ANSWER -easier it is to turn over
1. 4
2. 6
3. 2 - ANSWER -4 You are driving a combination vehicle when the
trailer breaks away, pulling apart both air lines.
You would expect the trailer brakes to come on
If you do not do the final air brake check for air and ...
leaks and fix them before driving, 1. the tractor to lose all air pressure
1. you could lose your brakes while driving 2. the tractor protection valve to close
2. your fuel usage will increase 3. the trailer supply valve to stay open -
3. tire pressure will drop - ANSWER -you ANSWER -the tractor protection valve to
could lose your brakes while driving close
Which part of the kingpin should the locking jaws When you drive a set of doubles, which shut-off
close around? - ANSWER -The shank valve must be closed in the last trailer?
1. Middle section
2. front section
Glad hands are used to connect the .... 3. back section - ANSWER -back section
1. kingpin from the trailer to the locking jaws of
the fifth wheel
2. electrical lines from the tractor to the trailer The fifth wheel locking lever is not locked after
3. service and emergency air lines from the truck the jaws close around the kingpin. This means
or tractor to the trailer - ANSWER -service that...
and emergency air lines from the truck or tractor 1. the parking lock is off and you may drive away
to the trailer 2. the trailer will not swivel on the fifth wheel
3. the coupling is not right and should be fixed
before you drive the coupled unit -
Trucks roll over more easily when fully loaded ANSWER -the coupling is not right and
and are should be fixed before you drive the coupled unit
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 What gear should the tractor engine be in after
than empty rigs you uncouple the trailer and are inspecting the
3. two times more likely to roll over in a crash trailer?
1/4
