1. Castor oil-alcohol type: It is made of 45%-55% refined castor oil and 55%-45% low-carbon alcohol (ethanol or butanol), and after precipitation, a colorless or yellowish clear and transparent liquid is obtained, that is, alcohol-based automobile brake fluid. Castor oil plus ethanol is alcohol type 1, and castor oil plus butanol is alcohol type 3. The raw materials of alcohol brake fluid are easily available, the synthesis process is simple, and the product has good lubricity; Disadvantages are low boiling point and unstable performance at low temperature. Alcohol type 1 ethanol vapor appears above 45℃, resulting in gas resistance; At -25℃, castor oil precipitates into milky white gel, which increases with the decrease of temperature, blocking the braking system and making the braking system seriously ineffective. The No.3 alcohol cup test found that the color of brake fluid was slightly dark, butanol slightly dissolved and corroded rubber, and white precipitate was also precipitated at -28℃. Some literatures introduced the regulation by adding glycerol, but precipitation and stratification still existed at low temperature. In cold winter and hot summer;
2. Synthetic type: made of ether, alcohol, ester and other additives such as lubrication, oxidation resistance, rust prevention and rubber swelling resistance;
3. Mineral oil type: made of refined light diesel oil fraction, thickener and other additives.
Million car purchase subsidy