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Use of Mineral Base Hydraulic Fluid in Automobile Applications
Published January 01, 1972 by Institution of Mechanical Engineers in United Kingdom
One problem affects the evolution of brake technology: regular increase in speed and power involves more and more kinetic energy to be converted into heat energy and requires higher hydraulic pressures. The main drawback of conventional brake fluids is their hygroscopicity which greatly affects their boiling point and may cause brake failure (vapor-lock). An enquiry on employees cars shows that 80 out of the 100 cars tested have a fluid whose vapor-lock temperature is lower than 150°C due to moisture absorption. Vapor-lock temperature determinations during road trials are presented as a function of the water content of conventional brake fluids. The vapor-lock phenomenon is eliminated by using mineral fluids featured by their high initial boiling point (215°C) which remains constant its life long (non hygroscopic), thus, mineral fluid makes driving safer. On the other hand, the trend is now to generalize the use of central hydraulic power systems for brakes and steering actuation and, in some cases, for gear box control and suspension. Mineral fluid gives the following advantages:
- it provides a better lubrication of the hydraulic circuit components as shown during hydraulic bench evaluation,
- its additive package ensures outstanding anti-corrosion protection as regards steel, cast iron, copper, brass and aluminum,
- the sludge formation is reduced by ten times compared to conventional synthetic fluids,
- lubrication and anti-corrosion properties reduce the vehicle overall costs.
Mineral fluid seems to be the most promising candidate for future brake systems and central hydraulic power systems. A European car maker has now acquired a 6 years' experience with such a Mineral Hydraulic Fluid