Instructions

Combination

All applicants who are applying for a Class A CDL should be prepared to take the Combination test. This test covers information found in Section 6 of the Commercial Driver License.. Read More

All applicants who are applying for a Class A CDL should be prepared to take the Combination test. This test covers information found in Section 6 of the Commercial Driver License Manual. Section 6 provides the information needed to safely operate tractor-trailers, doubles, triples, and straight trucks with trailers. The test is made up of 20 multiple-choice questions, and applicants will need to correctly answer a minimum of 16 questions to pass. The Combination test is not a replacement for the Double/Triple endorsement test.

Number of Question 20

Passing Score 16

1. What is another name for the service line?

The signal line

The cable line

The surplus line

The power line

The trailer service air line is also referred to as the control line or signal line.

2. When driving a tractor-trailer equipped with ABS, you should:

Stop harder than you would otherwise.

Use extra braking force to ensure the ABS kicks in.

Brake as you normally would.

Brake using less pressure than you would otherwise use.

When driving a tractor-trailer combination equipped with an Anti-Lock Braking System (ABS), you should brake in the same manner that you would in a vehicle without ABS.

3. While inspecting a coupling, you should go under the trailer and:

Detach the jaws from around the kingpin.

Make sure the locking lever is in the "emergency" position.

Remove the safety latch.

Look into the back of the fifth wheel.

While inspecting a coupling, you should go under the trailer and look into the back of the fifth wheel. Ensure that the fifth wheel jaws are secured around the shank of the kingpin.

4. Rollovers happen when:

A truck driver is driving too fast.

The driver of a vehicle in front of a truck is moving to slowly.

A truck driver is driving too slowly.

ABS is working effectively.

Rollovers happen when a vehicle is driven too fast. To reduce the risk of rollover, make sure the weight of cargo is loaded low to the ground, and that you take turns and curves slowly.

5. Using the trailer hand brake while experiencing a trailer jackknife will:

Stop the skid.

Straighten the trailer.

Increase traction.

Continue the skid.

If you are experiencing a trailer jackknife, you can help your tires regain traction by releasing the brakes. Using a trailer hand brake while experiencing a skid will only cause the skid to continue.

6. Emergency air lines are often coded with the color:

Green.

Orange.

Yellow.

Red.

In general, the parts of the service air line are coded blue and the parts of the emergency air line are coded red.

7. If oil and water build up in your vehicle's air tanks, the brakes:

May not work correctly.

May feel squishy.

Will squeal loudly when used.

Will be extremely sensitive.

Air tanks should be drained daily to remove water and oil buildup. An excess of oil and water in the air tanks can interfere with proper brake function.

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