COMMERCIAL DRIVER LICENSE
EXAM 2024-2025 LATEST UPDATED
COMPLETE 150 QUESTIONS WITH
DETAILED VERIFIED AND 100%
CORRECT ANSWERS BRAND NEW
EXAM GRADED A+
When should you use the hand valve to park a
combination vehicle? - ....ANSWER...Never
A driver crosses the air lines when hooking up to an old
trailer. What will happen? - ....ANSWER...If the trailer
has no spring brakes, he or she could drive away but
wouldn't have trailer brakes
You should supply air to the trailer tanks by: -
....ANSWER...Pushing in the trailer air supply valve
If the service air lines comes apart while you are driving
a combination vehicle but the emergency lines stay
together, what will happen right away? -
....ANSWER...Nothing is likely to happen until you try
to apply the brakes.
1
,Where should the tractor be when you inspect the
landing gear after uncoupling the trailer? -
....ANSWER...With the tractor frame under the trailer
What gear should the tractor transmission be in after
you have uncoupled the trailer and are
inspecting the trailer supports? -
....ANSWER...Neutral
Which of these statements is true? -
....ANSWER..."Bobtail" tractors can take longer to stop
than a combination vehicle loaded to maximum gross
weight
To be safe when driving behind other vehicles under
good conditions you should leave at least one second
between your vehicle ahead for each
_____________ feet of your vehicle's length. -
....ANSWER...10
When do you need to use chocks to park a trailer that
does not have spring brakes? -
....ANSWER...Always
2
,You are driving a combination vehicle when the trailer
brakes away, pulling apart both air lines. You would
expect the trailer brakes to come on and the :
- ....ANSWER...tractor protection valve to close
The air leakage rate for a combination of two
vehicles (engine off, brakes off) should not be
greater than ____ psi per minute. - ....ANSWER...3
When uncoupling a trailer, after you have shut off the
traielr air supply and locked the trailer brakes, you
should: - ....ANSWER...Back up gently to ease pressure
on the fifth wheel locking jaws
Loss of air pressure in the emergency line cause: -
....ANSWER...the trailer's emergency brakes to come on
In normal driving, some drivers use the hand valve before
the brake pedal to prevent a jackknife. Which of these
statements is true? - ....ANSWER...It should not be
The tractor protection valve will close and the trailer
emergency brakes will come on when there is a
major leak in the _________ brake line. -
....ANSWER...emergency
What will happen if the airlines are crossed when you
hook up to an old trailer? - ....ANSWER...If the
3
, trailer has no spring brakes; you could drive away but
you would not have trailer brakes
minimum tread depth in every major groove on front tires
- ....ANSWER...4/32 inch
This much tread is needed on other tires not including
front - ....ANSWER...2/32 inch
sterring wheel play of more than _____ can make it hard
to steer - ....ANSWER...10 degrees or two inches
movement at the rim
Most important reason for doing a vehicle inspection
- ....ANSWER...safety for yourself and road users
things to check during a trip - ....ANSWER...gauges, any
problems detected by senses, tires, brakes, lights, trailer
connections, cargo securement
A problem with spring hangers could show this -
....ANSWER...problem with suspension system defects
4
EXAM 2024-2025 LATEST UPDATED
COMPLETE 150 QUESTIONS WITH
DETAILED VERIFIED AND 100%
CORRECT ANSWERS BRAND NEW
EXAM GRADED A+
When should you use the hand valve to park a
combination vehicle? - ....ANSWER...Never
A driver crosses the air lines when hooking up to an old
trailer. What will happen? - ....ANSWER...If the trailer
has no spring brakes, he or she could drive away but
wouldn't have trailer brakes
You should supply air to the trailer tanks by: -
....ANSWER...Pushing in the trailer air supply valve
If the service air lines comes apart while you are driving
a combination vehicle but the emergency lines stay
together, what will happen right away? -
....ANSWER...Nothing is likely to happen until you try
to apply the brakes.
1
,Where should the tractor be when you inspect the
landing gear after uncoupling the trailer? -
....ANSWER...With the tractor frame under the trailer
What gear should the tractor transmission be in after
you have uncoupled the trailer and are
inspecting the trailer supports? -
....ANSWER...Neutral
Which of these statements is true? -
....ANSWER..."Bobtail" tractors can take longer to stop
than a combination vehicle loaded to maximum gross
weight
To be safe when driving behind other vehicles under
good conditions you should leave at least one second
between your vehicle ahead for each
_____________ feet of your vehicle's length. -
....ANSWER...10
When do you need to use chocks to park a trailer that
does not have spring brakes? -
....ANSWER...Always
2
,You are driving a combination vehicle when the trailer
brakes away, pulling apart both air lines. You would
expect the trailer brakes to come on and the :
- ....ANSWER...tractor protection valve to close
The air leakage rate for a combination of two
vehicles (engine off, brakes off) should not be
greater than ____ psi per minute. - ....ANSWER...3
When uncoupling a trailer, after you have shut off the
traielr air supply and locked the trailer brakes, you
should: - ....ANSWER...Back up gently to ease pressure
on the fifth wheel locking jaws
Loss of air pressure in the emergency line cause: -
....ANSWER...the trailer's emergency brakes to come on
In normal driving, some drivers use the hand valve before
the brake pedal to prevent a jackknife. Which of these
statements is true? - ....ANSWER...It should not be
The tractor protection valve will close and the trailer
emergency brakes will come on when there is a
major leak in the _________ brake line. -
....ANSWER...emergency
What will happen if the airlines are crossed when you
hook up to an old trailer? - ....ANSWER...If the
3
, trailer has no spring brakes; you could drive away but
you would not have trailer brakes
minimum tread depth in every major groove on front tires
- ....ANSWER...4/32 inch
This much tread is needed on other tires not including
front - ....ANSWER...2/32 inch
sterring wheel play of more than _____ can make it hard
to steer - ....ANSWER...10 degrees or two inches
movement at the rim
Most important reason for doing a vehicle inspection
- ....ANSWER...safety for yourself and road users
things to check during a trip - ....ANSWER...gauges, any
problems detected by senses, tires, brakes, lights, trailer
connections, cargo securement
A problem with spring hangers could show this -
....ANSWER...problem with suspension system defects
4
