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 Washington State Department of Licensing Commercial Driver.. 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 Washington State Department of Licensing Commercial Driver Guide. 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
Passing Score

8. Trailers built before ____ are not required to have spring brakes.

Explanation
Trailers built before 1975 are not required to have spring brakes. When parking a trailer without spring brakes, be sure to use wheel chocks to prevent the trailer from rolling.

9. When driving a vehicle equipped with an Anti-Lock Braking System (ABS), brakes should be applied:

Explanation
When driving a vehicle with ABS, you should brake in the same manner as you would in a vehicle without ABS.

10. Look into the back of the fifth wheel:

Explanation
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.

11. Operating combination vehicles usually requires ­­­­­____ operating single vehicles.

Explanation
Combination vehicles are usually heavier and longer than single combination vehicles. Operating a combination vehicle requires a higher level of driving skill than operating a single commercial vehicle.

12. If you must cross traffic while driving a combination vehicle, you should:

Explanation
Combination vehicles require more space on the road than other vehicles. When entering or crossing traffic while driving a combination vehicle, it is especially important that there is a large enonugh gap in traffic to safely do so.

13. Pushing in the trailer air supply control will:

Explanation
Push in the trailer air supply control to supply the trailer with air. Pull out the trailer air supply control to turn off the air supply and activate the emergency brakes.

14. The service air line is often controlled by the foot brake and is attached to the ____ valves.

Explanation
The service air line carries air and is controlled by either the foot brake or trailer hand brake. The service air line is attached to relay valves, which allow the trailer brakes to be applied quickly.
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