Which of the following might indicate a malfunctioning pneumatic system?

Inconsistent actuator movement is a strong indicator of a malfunctioning pneumatic system because it suggests that there may be issues with air supply, control mechanisms, or potential blockages within the system. In a properly functioning pneumatic system, actuators should respond predictably and reliably to control signals. If the movement of actuators varies significantly, it may point to underlying problems such as insufficient air pressure, malfunctioning valves, or other mechanical failures that prevent the system from operating as intended.

The other options do not suggest clear problems. For instance, no visible air leaks indicate that the system is retaining air properly, which is a sign of good maintenance. Steady pressure readings usually reflect that the system is operating within its designed parameters. Lastly, minimal noise from the machinery can often signify efficient operation, as excessive noise might indicate mechanical issues rather than normal function. Therefore, consistent actuator movement is essential for the performance of pneumatic systems, making its inconsistency a key sign of malfunction.