CDL COMBINATION VEHICLE EXAM,
PRACTICE EXAM AND STUDY GUIDE NEWEST
2024 ACTUAL EXAM 300 QUESTIONS AND
CORRECT DETAILE D ANSWERS WITH
(VERIFIED ANSWERS) |ALREADY GRADED A
Before a drive, ensure that air flows to all trailers by: -
ANSWER- Opening the rear shut-off valves and listening for escaping air.
Test the tractor protection valve by: - ANSWER- Releasing air
with the brake pedal.
Pull out the trailer air supply control to test: - ANSWER- The
trailer emergency brakes.
To prevent a rollover, a driver should: - ANSWER- Keep cargo
low.
One way to prevent a rollover is to: - ANSWER- Keep cargo
centered on the rig.
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In a sudden turn, the ____ trailer is the most likely to turn over. - ANSWER- Last.
Using the trailer hand brake while experiencing a trailer
jackknife will: - ANSWER- Continue the skid.
If you need to back your trailer but cannot back up in a straight
path, you should: - ANSWER- Back toward the driver's side.
Using the trailer hand valve while driving: - ANSWER- Can
cause a skid.
Push in the trailer air supply control to: - ANSWER- Supply the
trailer with air.
In a vehicle equipped with an automatic tractor protection valve,
the valve will pop out when: - ANSWER- Air pressure drops to
a level between 20 and 45 psi.
An air supply control in its "emergency" position will: -
ANSWER- Apply the trailer emergency brakes.
The service air line is attached to the: - ANSWER- Relay valves. 2 / 4
The emergency air line: - ANSWER- Supplies air to the trailer
air tanks.
Trailers built before 1975 are: - ANSWER- Not required to have
spring brakes.
While inspecting a coupling, you should go under the trailer
and: - ANSWER- Look into the back of the fifth wheel.
If you are operating a vehicle built before 1998 and are unsure if
the trailer has an Anti-Lock Braking System (ABS), you can: -
ANSWER- Check for wheel speed sensors coming from the back of the brakes.
After finishing a pre-trip inspection, you should: - ANSWER-
Close the emergency line valve. Close the service line valve.
During a trip, which shut-off valves should be open? - ANSWER- All shut-off valves should be in the open position, except the rear shut-off valves.
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To test the trailer service brakes, you should: - ANSWER- Move
the vehicle forward slowly and apply the brakes with the hand control.
____ are the cause of more than half of all accident-related truck driver deaths. - ANSWER- Truck rollovers.
When traveling more slowly than 40 mph, maintain at least ____ of following distance per every 10 feet of your vehicle. - ANSWER- One second.
Avoid needing to make sudden lane changes by: - ANSWER-
Watching the road ahead while driving.
A lightly-loaded combination vehicle will stop more slowly than
a fully loaded vehicle because: - ANSWER- The stiff
suspension springs and strong brakes will have low traction.
When driving a bobtail tractor, you should be aware that: -
ANSWER- Bobtails are more difficult to stop than tractors with semitrailers.
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