CDL Combination Test (2024) - FREE South Carolina CDL Practice Test

1. If the drive wheels start to skid:

accelerate slightly to regain control.
use the brakes to slow down.
push in the clutch to let them turn freely.
All of the above.

2. Cargo should be properly covered:

to protect the weather from the cargo.
to block your view or someone else’s.
to protect people from spilled cargo.
All of the above.

3. If your brakes get wet, it can cause them:

4. Which of the following is not a reason for covering cargo?

To prevent other drivers from looking at the cargo
To protect people from spilled cargo
To protect the cargo from weather
All of the above.

5. If your vehicle is equipped with air brakes, loss of air pressure in the emergency line causes:

the speed of your vehicle to increase.
the trailer spring brakes to come on.
the trailer emergency brakes to come on.
All of the above.

6. To test the tractor-semitrailer connection for security:

pull out the air supply knob.
check that the trailer is locked onto the tractor by pulling the tractor gently forward while the trailer brakes are still locked.
plug the electrical cord into the trailer and fasten the safety catch.
go under the trailer and look into the back of the fifth-wheel.

7. The emergency air line does NOT:

supply air to the trailer air tanks.
cause the tractor protection valve to close when the emergency line loses pressure.
pump air into the relay valves, allowing the trailer brakes to be applied more quickly.
control the emergency brakes on combination vehicles.

8. When backing a trailer, you should:

pull-up frequently to reposition the vehicle.
not back up in a straight line.
avoid braking.
turn the steering wheel toward the direction you want to go.

9. If ABS is not working:

you should use the emergency brake.
you will not have any brakes.
you should use the parking brake.
you will still have brakes.

10. When you have to back, you should always try to back toward the driver's side. Why?

You can watch the front of your vehicle by looking out the side window.
You can see better and watch the rear of your vehicle by looking out the side window.
Backing toward the left side is more dangerous.
All of the above.

COMBINATION TEST SOUTH CAROLINA - PRACTICE TEST