South Carolina CDL Permit Test - Double

Number of questions: 20
Passing score: 16
Directions: This endorsement is required if the driver will pull two or three trailers. To receive this endorsement, applicants must pass a test. The test consists of 20 multiple choice questions. To pass, the applicant must answer at least 16 questions correctly. Each question has two, three or four possible answer choices. Test questions come from the South Carolina Commercial Driver License Manual. Questions come from chapters covering: Driving Safely, Air Brakes (if applicable), Combination Vehicles and Doubles and Triples. The Double/Triple endorsement can be used with the Class A CDL.
You have made error so far
Passing grade —
4 or fewer errors
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1.
Which of the following is not a cause of hydraulic brake failure?
Loss of hydraulic pressure
Brake fade on long hills
Downshifting
2.
Without engine oil:
The vehicle will get better gas mileage
The engine can be destroyed quickly
The ABS won’t work properly
The windshield wipers will not operate
3.
If using spring brakes when hauling a heavy load, a complete stop will:
Be impossible.
Take a long time.
Take a short amount of time.
4.
When should the trailer hand valve be used?
To test the trailer brakes
To check the connection between the trailer and tractor
To accelerate
To test the lights on the trailer
5.
Often driving outside of your lane may be a sign of fatigue.
TRUE
FALSE
6.
One way to prevent drowsiness while driving is to:
Drive alone.
Not exercise regularly.
Get adequate sleep the night before the trip.
7.
When entering a curve, you should:
Get off the roadway
Use the shoulder
Downshift
Take the vehicle out of gear
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