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 it is not able to escape from the back of the vehicle.

Rear service line shut-off valve

Rear supply line shut-off valve

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.

Close the emergency line valve.

Leave the service line valve open.

Close the emergency line valve.

Combination vehicles need more space on the road than other commercial vehicles because they are longer and need more space to turn and stop. It is especially important to properly manage space when you are operating a combination vehicle.

Need more space to turn and stop than other commercial motor vehicles.

Drive more slowly than other commercial motor vehicles.

Are heavier than other commercial motor vehicles.

Need more space to turn and stop than other commercial motor vehicles.

If you are operating a vehicle built before 1998 and are unsure if the trailer has an Anti-Lock Braking System (ABS), you can check under the trailer for wheel speed sensors coming from the back of the brakes.

Check for wheel speed sensors coming from the back of the brakes.

Pump the air brakes to activate the ABS.

Look into the back of the fifth wheel.

Check for wheel speed sensors coming from the back of the brakes.

Older trailers do not have spring brakes. This means that if the air supply in an older trailer's air tank has leaked away, there will be no working brakes connected to the trailer and its wheels will turn freely.

The trailer will not have brakes.

The trailer will stop normally.

The trailer will not have brakes.

Combination Vehicles Practice Test | Montana 2025 #1

Train for FREE online with our Montana CDL combination vehicle test. The official exam test consists of several obligatory parts, with all of them checking your knowledge of different blocks of road rules. If you need to obtain a MT combination license in 2025, practice as much as possible. Free sample tests published on our website will help you check and improve your knowledge and boost your grades. Please bear in mind that DMV requirements for issuing a combination license may vary from state to state.

Number of Question 20

Passing Score 16

Number of Tests 20

Combination Vehicles Practice Test | Montana 2025 #1

1 . During a trip, the ____ should be open.

2 . Before beginning a trip, you should:

3 . Push in the trailer air supply control to:

4 . Trailers with low underneath clearance can present challenges when driving over:

5 . Combination vehicles need extra space on the road because they:

6 . To find out if a vehicle that was built before 1998 has an Anti-Lock Braking System (ABS), you can:

7 . Older trailers are not equipped with spring brakes. This means that if the air supply for a vehicle's air braking system leaks away:

Search the best driving school in your neighbourhood

Wait, before you go