Brake fluid characteristics

Materials compatibility

Brake fluids must be compatible with brake system materials. Seals swelling tests are carried out at 70°C and 120°C on standardized SBR and EPDM rubber specimens and on specific elastomers used by OEMs. During these tests changes in the volume, diameter and hardness of the specimens are measured.

Anticorrosion protection

Additives (corrosion inhibitors) are added to the base fluid to protect metal used inside components such as calipers, master cylinders… against corrosion

Oxidative resistance and Thermal stability

Braking is the conversion of kinetic energy into heat by friction. The quantities of heat that result are considerable and depend on the weight and speed of the vehicle.

Nevertheless, under extreme conditions of operation, brake fluids reach temperatures of more than 150°C. Their cracking phenomenon is a direct measure of their thermal stability. This is determined by the quality of glycol ethers components and the quantity and nature of antioxidants.

Antioxidants improve the thermal stability and also hold up the aging of the fluid by oxidation into acidic components.