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.