How should the governor cut-out pressure be checked?

The governor cut-out pressure is a critical component in a truck's air brake system. To check how the governor cut-out pressure functions properly, air pressure must be allowed to build within the system until it reaches a predetermined level, at which point the governor will activate and release pressure. This action is visually verified by observing the air pressure gauge during this process.

When the air system builds pressure, the gauge will rise until the governor reaches its cut-out point. Once this point is reached, the governor should release the excess air, and the gauge will drop accordingly. This cut-out action confirms that the governor is functioning correctly, ensuring that the air brakes will operate safely and efficiently.

The other answer choices involve different methods which do not provide the correct assessment of the governor cut-out pressure. For instance, manually releasing air from the system may offer insights into air system function but does not directly measure the cut-out pressure. Inspecting the governor for leaks focuses on potential issues rather than confirming its operational parameters. Checking the manufacturer's manual for specifications can offer baseline data, but it doesn't involve the practical checking of the governor's cut-out pressure in real-time operation, which is the method that provides immediate verification of its functionality.