The single most important factor in determining the best choice of hydraulic fluid to use is viscosity, otherwise known as the fluid's weight. Viscosity is also most often expressed as the fluids ISO number or grade.
It is recommended that a proper hydraulic fluid is used as these fluids do not contain harmful additives that can cause damage to components, and are designed to work within a specific temperature range.
Higher viscosity hydraulic fluid tend to reduce the system's operating temperature by increasing the volumetric efficiency of the pump. If the viscosity is too high, however, this will cause poor mechanical efficiency by increasing friction during start-up which may lead to cavitation.
Finding the right ISO grade that balances the benefits of volumetric efficiency against the drawbacks of mechanical efficiency is the key to a good long term oil choice. Ultimately the manufacturer of the equipment will specify the most apt oil for their machinery.
We recommend ISO 32 as a year round hydraulic oil suitable for all our Vehicle Lifts that employ a 2.2KW motor to drive the pump. Our equipment typically operates at 25 Mpa.
In hotter climates, or during prolonged periods of hot weather, consideration of the use of ISO 46 grade oil may be given.
Information Regarding the Installation, Maintenance and Repair of Strongman Tools Ltd Vehicle Lifts