Because hydraulic fluid is virtually incompressible, it enables immediate transmission of power around the system. Different parts of the hydraulic system need to be lubricated individually, the key components being several types of pump and valves.

Hydraulic fluids come in a number of different formulations. Most are mineral-based, water-based or synthetic, and within these three categories they have varying degrees of viscosity, oxidation stability, wear resistance and seal compatibility, as well as containing different additive combinations.

It’s important to choose a suitable hydraulic fluid for its intended use and targeted part of the system. For example, hydraulic valve lifter fluid is added to the engine oil to clean away dirty deposits, restoring efficiency of the valve lifters and reducing engine noise. Central hydraulic fluid is used to improve power steering, hydraulics and suspension-level control, among other applications.