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 Wisconsin Commercial.. 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 Wisconsin Commercial Driver's 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

8. Place the trailer air supply control in its "emergency" position to test:

The trailer emergency brakes.

A coupling device.

The anti-lock brakes.

Be sure to test the trailer emergency brakes before beginning a trip. After ensuring that the trailer rolls freely, you can test the emergency brakes by pulling out the trailer air supply control, or placing it in the "emergency" position. Pull forward slightly with the tractor and make sure the trailer does not move.

9. When a combination vehicle goes around a corner:

The turn should be made as tightly as possible.

The front and rear wheels move in different paths.

The rear wheels should run over the curb.

It is acceptable for street signs to be knocked over if they are too close to the road.

When a vehicle goes around a corner, the rear wheels follow a different path than the front wheels. This is called off-tracking. This effect is especially pronounced on vehicles with trailers.

10. If a trailer begins to skid, it is best for the driver to:

Release the brakes.

Accelerate.

Quickly turn the steering wheel in one direction, then in the other.

If your trailer begins to skid, you should release the brakes to regain traction. The trailer will begin to straighten out once the wheels begin to grip the road again.

11. A loss of air pressure in the emergency line will cause:

The suspension springs to extend.

The tractor protection valve to open.

The rear trailer to detach from the combination.

The emergency brakes to activate.

The emergency air line controls the emergency brakes on a combination vehicle. A loss of air pressure in the emergency line will cause the emergency trailer brakes to activate.

12. 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.

13. If a trailer begins to skid, the driver should:

Lock the brakes.

Release the brakes.

Steer in the opposite direction.

Accelerate.

If your trailer starts to skid while you are braking, you should release the brakes and allow them to begin to regain traction. Once its wheels have regained their grip on the road, the trailer will begin to straighten out and follow the tractor.

14. 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.

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