TDR Brake Fluid DOT 4 is an efficient performance non- petroleum automotive brake fluid, designed for use in conventional hydraulic brakes and clutch systems, where DOT 4 fluids are recommended. Brake Fluid DOT 4 is a complex mixture of polyglycol ethers, glycol ether borate esters and polyglycols with additional corrosion and oxidation inhibitors. Wet boiling point up to 170°C.