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Drivers who want to drive combination vehicles must pass the combination vehicles test. The Tennessee CDL combination test consists of 20 questions, and you'll need at least 16 correct answers to pass (80%). The test covers the combination vehicles section of the Tennessee CDL Manual. Take this practice test now to prepare for the actual TN CDL combination test!
1. Most hydraulic brake failures occur for one of two reasons, one of which is:
excessive downshifting.
driving in cold weather.
relying too much on the engine braking effect.
loss of hydraulic pressure.
2. After the pre-trip inspection, drivers should inspect their cargo and its securing devices again within ________ after beginning the trip.
20 miles
50 miles
25 miles
two hours
3. Strong winds can make it difficult to stay in your lane, especially when:
driving alongside other vehicles.
going into tunnels.
coming out of tunnels.
driving at speeds below 40 mph.
4. Air brakes use ________ to make the brakes work.
compressed gas cylinders
compressed air
compressed oil
compressed gases
5. The use of brakes on a steep downgrade is:
much more effective than the engine braking effect.
a supplement to the braking effect of the engine.
dangerous, and should be avoided at all costs.
the main braking factor.
6. You should not use the trailer hand brake to straighten out a jackknifing trailer. Why?
The brakes on the trailer wheels caused the skid in the first place.
You should use the emergency break instead.
The brakes on the trailer wheels will not respond.
You should use the service break instead.
7. When you get ready to back under the semi-trailer, you should:
line up directly in front of the trailer.
back under the trailer at an angle to avoid pushing the trailer sideways.
line up about 15 degrees off the line of the trailer.
line up the kingpin to engage the driver's side locking jaw first.
8. The trailer hand valve should:
never be used for parking.
be used in driving.
never be used to test the trailer brakes.
All of the above.
9. The best way to recognize that your trailer has started to skid is:
by using retarders.
by hearing squeaking noises from the wheels.
by seeing it in your mirrors.
None of the above.
10. To secure the tractor you should:
Check that the kingpin and the fifth-wheel are aligned.
Put on the parking brake and put the transmission in neutral.
Connect the tractor service air-line to the trailer service glad hand.
All of the above.
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TN CDL Combination Test

Number of questions: 20
Correct answers to pass:16
Passing score:80%
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