The most common causes of poor hydraulic performance are particulate contamination, water contamination, clogged filters, high fluid temperature and incorrect hydraulic fluids.
Cavitation occurs when the oil volume demanded by any part of a hydraulic circuit exceeds the oil volume supplied. This causes the absolute pressure in that part of the circuit to fall below the vapor pressure of the hydraulic fluid. This results in the formation of vapor cavities within the fluid, which implode when compressed, causing a characteristic knocking noise.
Cavitation causes metal erosion, which damages hydraulic components and contaminates the fluid. In extreme cases, cavitation can cause mechanical failure of system components.
Water not only affects the components of a hydraulic system, but also change the fluid itself, physically and chemically. The physical properties most affected by the presence of water include:
This leads to increased component wear, shortens the life of the pump & other equipment. Presence of water in the system builds a corrosive environment.