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 Alaska 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 Alaska 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

15. When should the trailer hand valve be used?

Only when the trailer is carrying a load

Only to test the trailer’s brakes

Only in inclement weather when the trailer may skid

The trailer hand valve, also called the trolley valve or Johnson bar, is used to work the trailer brakes. It should be used only to test the brakes. Using it while a vehicle is in motion could cause a skid.

16. Look into the back of the fifth wheel:

While testing your air brakes.

If your vehicle begins to skid.

When inspecting a coupling.

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.

17. Fully-loaded rigs:

Are less likely to roll over than empty rigs.

Are more likely to roll over than empty rigs.

Are just as likely to roll over as empty rigs.

Fully-loaded rigs are more vulnerable to rolling over than empty rigs because the weight of the cargo gives the vehicles higher centers of gravity.

18. After completing a pre-trip inspection, you should ensure that the:

Service line valve is closed.

Trailer hand brake is applied.

Emergency line valve is open.

Before a trip, you should ensure that air reaches all air brakes on all trailers by opening up the rear emergency line and service line shut-off valves and listening for escaping air. Close both shut-off valves before beginning to drive.

19. Shut-off valves:

Prevent air from escaping air brake systems.

Prevent air from entering air brake systems.

Override vehicles that are out of control.

Shut-off valves are used in air supply lines to control the passage of air from one trailer to another. The rear shut-off valve should always be closed to prevent air from leaving the braking system.

20. When braking with ABS, you should:

Push the brake pedal harder than usual.

Push the brake pedal as you normally would.

Push the brake pedal more lightly than usual.

When operating a vehicle with an Anti-Lock Braking System (ABS), you should apply your brakes in the same manner as you would if operating a vehicle without ABS.

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