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 California 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 California Commercial Driver Handbook. 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 17 questions to pass. The Combination test is not a replacement for the Double/Triple endorsement test.

Number of Question 20

Passing Score 17

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

The suspension springs to extend.

The tractor protection valve to open.

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.

2. When connecting a converter dolly to a second trailer, the trailer height should be ____ the center of the fifth wheel.

Level with

Slightly higher than

Slightly lower than

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

3. In a sudden turn, the ____ trailer is the most likely to turn over.

Front

Last

Middle

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.

4. 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.

5. All trailers made after ____ must be equipped with Anti-Lock Braking Systems (ABS).

1943

1998

2009

All trailers and converter dollies manufactured on or after March 1, 1998 must have Anti-Lock Braking Systems (ABS).

6. An air supply control lever should be in its "normal" position when you are:

Changing a tire.

Applying the trailer emergency brakes.

Pulling a trailer.

Tractor protection controls in older vehicles may be operated by levers instead of knobs. If an air supply control is set in its "normal" position, it is properly set for you to pull a trailer.