Brake fluid composition comprising tartaric acid and imidazole

A brake fluid composition comprising:

• (a) 85-99 wt % of a glycol compound and a boron-containing compound as a solvent;
• (b) 0.5-10.0 wt % of a corrosion inhibitor;
• and
• (c) 0.5-5.0 wt % of a mixture of tartaric acid and imidazole as an antioxidant;
• wherein the glycol compound as the solvent is comprised with 5.0-30 wt % of polyalkylene glycol and 60-85 wt % of glycol ether, based on the total weight of the solvent;
• wherein the glycol ether is one or more selected from the group consisting of triethylene glycol mono-methyl ether, polyethylene glycol mono-methyl ether and polyethylene glycol mono-butyl ether;
• wherein the boron-containing compound as a solvent is included with 1.0-30 wt % of tris[2-[2-(2-methoxyethoxyl)ethoxy]ethyl]orthoborate, based on the total weight of the solvent;
• wherein the corrosion inhibitor is a mixture of tolyltriazole and an amine compound;
• and
• wherein the amine compound is alkyl diethanol amine or cyclohexyl amine.