UNE 26-327-1989 Motor vehicles. Hydraulic braking. Methods for Shear Stabilization of Petroleum-Based Brake Fluids and Injectors of Integrated Polymer-Containing Oils
This standard specifies the method for measuring the percentage loss of viscosity, at 100 °C, of oils containing polymers. The loss of viscosity is a direct function of the degradation of the polymer due to the shear conditions to which it is subjected in the testing apparatus. It applies to hydraulic and hydropneumatic braking systems of motor vehicles and their trailers.