Common indicators of a problem with the system or a component include excessive noise or heat, incorrect flow or pressure, and incorrect operation.
Excessive noise from a hydraulic pump or valve can be caused by air in the system, a misaligned coupling, or a worn or damaged motor or pump.
Excessive heat may be the result of a relief or unloading valve set too high, system pressure that is too high, defective fluid cooling, or a worn pump, valve, motor, cylinder or other component.
Incorrect operation could include having no flow, which could be caused by a damaged pump or drive motor. Low or excessive flow could result from a flow control set too low or too high, or from a leak in the system. No movement, slow or intermittent movement, and extreme speed or movement are all indicators of system error.
Three simple maintenance procedures increase hydraulic system performance, efficiency and life:
1. Maintain a sufficient amount of clean hydraulic fluid of the proper type and viscosity/ grade;
2. Change filters and clean strainers regularly;
3. Keep all connections tight to prevent aeration; but not overly tight to the point where the valve body is damaged, which can result in metal cuttings entering the hydraulic system.