CDL Practice Tests

Doubles and Triples Test

Page Border

Question #1 of 24

Doubles and Triples Test Question Image

Charge the trailer air brake system and push in the air supply knob. Shut the engine off. Pump the brake pedal several times to reduce the air pressure in the tanks. The trailer air supply control should pop out when the air pressure falls into the range specified by the manufacturer.

This is a tractor protection valve test.

This is a trailer emergency brake test.

This is how can you test that air flows to all trailers.

This is a trailer service brake test.

This is an air pressure gauge test.

None of the above.

Doubles and Triples Endorsement Requirements

Each applicant for the doubles and triples endorsement must have knowledge covering procedures for assembly and hookup of the units, proper placement of heaviest trailer, as well as handling and stability characteristics.

The applicant must also be able to identify potential problems in traffic operations, including problems the motor vehicle creates for other motorists due to slower speeds on steep grades, longer passing times, possibility for blocking entry of other motor vehicles on freeways, splash and spray impacts, aerodynamic buffeting, view blockages, and lateral placement as well as operating practices and procedures not otherwise specified.

CDL Test Source: Electronic Code of Federal Regulations.


CDL Practice Test (Home) | General Knowledge Test | General Knowledge Test Part 2

True/False General Knowledge Challenge | Hazmat Test | Hazmat True/False Test | Air Brake Test

Air Brake Test (New) | Combination Vehicles Test | Doubles and Triples Test | Tanker Test

Pre-Trip Inspection | Truck Driver Requirements | School Bus Test | Passenger Vehicle Test

Class A CDL Test #1 | Class A CDL Test #2 | Class B CDL Test #1 | Class B CDL Test #2

CDL Learning Series | CDL Training Information

Privacy Policy  |  Contact

© 2020