Hydraulic systems operate under extremely close tolerances and high pressure, making them susceptible to small amounts of contamination. Keeping the environment clean in industrial settings can reduce the risk of contamination, but off-highway and mining equipment expose their hydraulic systems to large amounts of dust and water.

Regardless of the hydraulic system’s application, parts of the equipment are constantly exposed to the environment. Malfunctioning seals allow abrasives, water and air into the system, causing irregular operations and shorter equipment life.

Testing hydraulic fluid will determine if the fluid is capable of maintaining normal operations. Oxidation stability is required to prevent sludge from forming, and sufficient water separability and air release properties will resist foaming. Hydraulic fluid analysis also can confirm viscosity and anti-wear properties.