Koizumi, N., "Effect of Phenolic Brake Piston Tribology on Brake Pedal Feel," SAE Int. J. Mater. Manf. 7(1):1-9, 2014, doi:10.4271/2013-01-2051.
Phenolic brake pistons show excellent performance for weight saving, protection against vapor lock, noise reduction, no rust, and less seal scratch. Phenolic brake pistons have been successfully used since 1974. However there has been a complex system phenomenon related with the brake pedal feel.Our recent study focused on the tribology of phenolic brake piston and its correlation to brake pedal feel. Several surface designs of phenolic brake pistons were created and evaluated using modified JASO C448 bench test station. Our testing found the friction force between a phenolic brake piston and the piston seal differs from that of a steel brake piston. Furthermore, we discovered the friction forces on a phenolic piston could be favorably altered by the surface design of the piston.In this paper, we will propose how to improve brake pedal feel using a phenolic brake piston through designing the surface condition of the brake piston.