Dolly Inspection - ONLINE CDL SCHOOL

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Dolly Inspection

Build confidence with 10 original questions about Dolly Inspection. Review your answers and explanations after finishing.

Supplemental study practice. This is not a government licensing exam or ELDT certification, and does not replace hands-on training. Follow your state’s current handbook.

1 / 10

After coupling a converter dolly to a rear trailer, what is the correct way to check that the coupling is secure?

Check only the safety chains

Pull against the pin of the second semitrailer

Rely on visual inspection alone

Drive forward quickly

2 / 10

You are preparing to uncouple the rear trailer from a double combination. The trailer does not have spring brakes. What should you do before uncoupling?

Chock the wheels of the second trailer

Open all shut-off valves

Lower the landing gear completely

Release the converter dolly fifth wheel latch

3 / 10

While positioning a converter dolly in front of the second trailer, what should you do if the dolly has spring brakes?

Open the air tank petcock

Use the dolly parking brake control to release the brakes

Disconnect the safety chains

Leave the brakes engaged for safety

4 / 10

During a pre-trip inspection, you notice the converter dolly air tank drain valve is open. What should you do before operating the vehicle?

Open all other valves for balance

Close the converter dolly air tank drain valve

Remove the dolly from the combination

Leave the valve open for ventilation

5 / 10

You are inspecting a converter dolly during your walkaround. What should you check about the safety chains?

They are disconnected for easy movement

They are secured to the trailer

They are wrapped around the landing gear

They are lying on the ground

6 / 10

You are about to connect air hoses between the converter dolly and trailer. What should you check before connecting them?

That air lines are lying on the ground

That air lines are tied tightly to the frame

That air lines are supported and glad hands are properly connected

That air lines are disconnected for safety

7 / 10

While preparing to couple a converter dolly to the rear trailer, you notice the trailer is slightly higher than the center of the fifth wheel. What should you do before backing the dolly under the trailer?

Raise the trailer higher to ease coupling

Back the dolly under and force it to fit

Leave the trailer as it is and proceed

Lower the trailer so it is just below the center of the fifth wheel

8 / 10

After coupling doubles, how do you confirm that air is reaching the rear of the second trailer?

Check the dashboard air pressure gauge only

Open the emergency line shut-off at the rear and listen for air escaping

Tap the trailer tires with a hammer

Press the brake pedal and look for warning lights

9 / 10

During a walkaround inspection, you see the shut-off valves at the rear of the last trailer are open. What should you do?

Disconnect the air lines

Open the valves wider

Leave them open for air flow

Close the shut-off valves at the rear of the last trailer

10 / 10

You are preparing to uncouple the converter dolly from the first trailer. What must you do before releasing the pintle hook?

Release the fifth wheel latch on the dolly

Lower the dolly landing gear and apply spring brakes or chock wheels

Drive the tractor away quickly

Disconnect the light cords first

Your score is

The average score is 0%

About the Dolly Inspection practice quiz

This practice quiz focuses on Dolly Inspection, listed under CDL Practice — Doubles and Triples. Use it to check what you understand, spot topics to revisit, and connect the material to safe, informed decisions on the road.

Before you begin

Keep your current CDL manual or course notes nearby. Read each prompt carefully and think through why an answer fits, especially when a question describes a vehicle, road, or workplace situation. Licensing rules and procedures can vary, so confirm requirements with current official materials for your state.

After you finish

Review any explanations shown with your results. Note unfamiliar terms or missed concepts, then revisit your manual or course notes before trying again. Use your score to guide study; understanding why an answer is correct matters more than the number alone.

Study note: These quizzes are independent study practice. They are not state licensing exams, official government materials, or ELDT certification, and they do not replace required training.

Explore CDL Tests to find more practice by subject.