Combination

Directions

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 Montana Commercial Driver License..

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 Montana 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 have 20 minutes to correctly answer a minimum of 16 questions. The Combination test is not a replacement for the Double/Triple endorsement test.

Passing grade:

The ____ trailer is the most likely to turn over if a driver takes a turn too quickly.

Explanation
When making a turn, be sure to steer gently and smoothly. Making a quick turn while pulling trailers is dangerous and can increase the risk of the last trailer rolling over.

Bobtail tractors are ____ to stop than tractors attached to full semitrailers.

Explanation
Bobtail tractors are tractors that are not attached to any semitrailers. When operating a bobtail, you should be aware that stopping can be difficult and that it will take a longer distance to come to a complete stop than a tractor attached to a loaded semitrailer.

What is a tractor protection valve?

Explanation
In a combination vehicle with air brakes, the tractor protection valve keeps air in the tractor or truck brake system in the event of the trailer breaking away or developing a leak.

To lower the risk of a rollover, you should:

Explanation
To lower the risk of a rollover, load your cargo as closely to the ground as possible. To further reduce this risk, take curves and corners slowly.

When connecting a converter dolly to a second or third trailer, the trailer height should be:

Explanation
When connecting a converter dolly to a second or third trailer, the trailer height should be correct. It should be slightly lower than the center of the fifth wheel.

A shut-off valve:

Explanation
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.

During a trip, which shut-off valves should be open?

Explanation
When starting a trip, be sure that all shut-off valves are in the open position, except for the last valves on the rear trailer. It is important that air reaches the brakes on all trailers and that the air is not able to escape from the back of the vehicle.
DMV Writen Test Logo