What does chattering of a hydraulic pump indicate?

Chattering of a hydraulic pump typically indicates that air is entering the pump. When air enters the hydraulic system, it can lead to a phenomenon known as "cavitation," where vapor bubbles form and collapse within the pump. This results in a rhythmic, rattling sound, which is referred to as chattering. The introduction of air disrupts the smooth flow of hydraulic fluid, causing variations in pressure and potentially leading to erratic pump operation.

In a hydraulic system, it's essential to maintain a fluid medium that is free of air to ensure optimal performance, efficiency, and longevity of the pump. If air is present, it can significantly diminish the system's responsiveness and increase wear on components, which aligns with the chattering characteristic observed in a malfunctioning hydraulic pump.