Combination Home Work

Front

What is the purpose of the hand valve in a combination vehicle?

Back

The hand valve is used to test the trailer brakes.

Front

What should be done if the fifth wheel lever is not locked after the jaws close around the king pin?

Back

The coupling is not correct and should be corrected before driving the coupled unit.

Front

How do you secure the tractor after pulling it to the proper distance in front of the trailer?

Back

Engage the parking brakes with the transmission in neutral.

Front

At what air pressure range should the trailer air supply control valve automatically close?

Back

The trailer air supply control valve should automatically close when the air pressure falls to between 20 and 45 PSI.

Front

What is the function of the service air lines in a combination vehicle?

Back

The service air lines carry air to the trailer service brakes.

Front

What is the role of the fifth wheel in a combination vehicle?

Back

The fifth wheel connects the tractor to the trailer and allows for articulation.

Front

What safety checks should be performed before driving a coupled unit?

Back

Ensure the fifth wheel is locked, the hand valve is released, and the coupling is correct.

Front

What is the function of the parking brake in a combination vehicle?

Back

The parking brake is used to keep the vehicle stationary when parked.

Front

What happens if the air pressure in the trailer drops too low?

Back

The trailer air supply control valve will close, preventing air from reaching the trailer brakes.

Front

Why is it important to engage the parking brakes with the transmission in neutral?

Back

Engaging the parking brakes with the transmission in neutral prevents the vehicle from rolling.