CDL Doubles and Triples Practice Test 2

Question 1

What is the correct position of the converter dolly air drain valve during the pre-trip inspection?

Accepted Answer

Fully closed

Answer

During the pre-trip inspection, the converter dolly air drain valve should be fully closed. This valve is primarily used to drain moisture or contaminants from the air tank. Keeping it closed during operation is essential to maintain proper air pressure within the braking system, as an open valve would cause a continuous air leak and lead to a loss of brake pressure.

Question 2

Which of the following driving practice is recommended for doubles/triples?

Accepted Answer

Allow more following distance

Answer

Doubles and triples are significantly longer and heavier than single trailers, requiring much greater stopping distances. Allowing more following distance provides the driver with additional time and space to react to hazards and brake safely. This practice helps compensate for the increased momentum and potential for jackknifing or rollovers associated with multi-trailer combinations.

Question 3

What is the correct amount of space between the upper and lower parts of the fifth wheel on the dolly when coupled to a trailer?

Accepted Answer

No space

Answer

When a converter dolly is properly coupled to a trailer, there should be no space between the upper and lower fifth wheel components. A tight connection ensures that the trailer is securely attached and prevents excessive movement or play, which could lead to instability or separation. Any gap indicates an improper or unsafe connection that needs to be corrected for safety.

Question 4

What should be inspected on the landing gear for doubles/triples?

Accepted Answer

All the above

Answer

During a pre-trip inspection of doubles/triples, all aspects of the landing gear must be thoroughly checked. This includes ensuring they are fully raised with no missing parts, that the crank handle is properly secured, and that there are no air or hydraulic leaks if power-operated. These comprehensive checks confirm the landing gear is in a safe, operational condition and won't interfere with driving or detach during transit.

Question 5

Where will you find shut off valves on doubles and triples?

Accepted Answer

[*]Both service and emergency air lines

Answer

Shut-off valves are found on both the service and emergency air lines of doubles and triples. These valves are critical for controlling the flow of air to the brake systems of each trailer. They must be correctly positioned (open for intermediate connections, closed for the last trailer) to ensure proper air pressure and braking function throughout the entire vehicle combination.

CDL Practice Test

CDL Practice Test

CDL Doubles and Triples Practice Test 2