Can Different Types of Brake Fluid Be Mixed?

[OJaxson]

Brake fluid should not be mixed. Different types and brands of brake fluid have varying compositions, and mixing them can lead to a decline in performance and chemical reactions, which may reduce braking effectiveness and impact the fluid's temperature resistance, thereby compromising driving safety. Brake fluid is a functional liquid used to stop wheel rotation, serving to transmit energy while also providing anti-corrosion, anti-rust, and lubrication benefits. Types of brake fluid: Castor oil-alcohol type, made from refined castor oil and low-carbon alcohol; synthetic type, formulated with ethers, alcohols, esters, and additives for lubrication, oxidation resistance, rust prevention, and rubber swelling resistance; mineral oil type, produced from refined light diesel fractions with thickeners. Precautions for using automotive brake fluid: If gasoline, diesel, or engine oil accidentally mixes with synthetic brake fluid in the braking system, incompatibility between fluids can reduce braking performance. After driving 40,000 kilometers or using brake fluid continuously for over two years, the fluid may degrade due to prolonged use, so timely replacement is essential. For vehicles equipped with a brake fluid level warning device, regularly check if the warning light is flashing and ensure the sensor is functioning properly. When brake fluid is low, replenish it promptly, keeping the stored fluid between the minimum and maximum marked levels. If braking feels inconsistent during normal driving, replace the brake fluid immediately. Before replacement, clean the braking system with alcohol. If the vehicle pulls to one side during braking, conduct a comprehensive inspection of the braking system. If the wheel cylinder rubber cup is excessively swollen, it may indicate poor-quality brake fluid. Replace it with high-quality brake fluid and change the rubber cup simultaneously. During seasonal changes, especially in winter, if braking performance declines, the brake fluid grade may not suit winter conditions. In such cases, choose a low-viscosity brake fluid for cold temperatures. Do not mix different types or brands of brake fluid. For braking systems with special requirements, use the specified brake fluid. Different formulations can degrade performance. Even brands claiming compatibility may not perform satisfactorily, so avoid long-term mixed use. If water, impurities, or sediment contaminate the brake fluid, replace or filter it promptly to prevent insufficient braking pressure and reduced effectiveness. Regularly replace brake fluid: Brake fluid volume changes with temperature, so the reservoir has a vent hole. Moisture or impurities in the air absorbed through this hole can lower the fluid's boiling point. Prolonged braking heats the system, potentially causing vapor lock, compressed air, and reduced braking power or failure. For safety, replace brake fluid periodically.