What is a common sign of hydraulic fluid leaks?

Visible stains or puddles are indeed a common sign of hydraulic fluid leaks. When hydraulic fluid leaks from a system, it often creates noticeable marks on surfaces it contacts or accumulates in puddles on the ground. The presence of these stains indicates not only the source of the leak but also highlights a loss of fluid from the hydraulic system, which could lead to inadequate lubrication, pressure loss, or potential system failure if not addressed promptly. This physical evidence is a straightforward way for operators and maintenance personnel to identify a leak and take corrective action.