What are common signs of a failing actuator?

Actuators show typical failure signs like erratic or slow movement, failure to reach set positions, unusual noises (grinding, hissing, humming), excessive vibration, visible leaks (pneumatic/hydraulic) or overheating (electric), tripped circuits, incorrect position feedback, and loss of fail-safe operation—these issues often stem from wear, misalignment, contamination, electrical faults or insufficient maintenance, and can disrupt industrial process control if unaddressed.