Can Brake Fluids Be Mixed?

[DeHenry]

Brake fluids should not be mixed. Different types and brands of brake fluids contain varying compositions of fluid components. Mixing them can lead to a decline in performance indicators and chemical reactions, which may reduce the vehicle's 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 Fluids: 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 anti-rubber swelling; Mineral oil type, produced from refined light diesel fractions with thickeners added. Precautions for Using Automotive Brake Fluid: If gasoline, diesel, or engine oil accidentally mixes into a synthetic brake fluid-based braking system, the incompatibility between fluids can also reduce braking performance. For vehicles driven normally for 40,000 kilometers or with brake fluid used continuously for over 2 years, the fluid is prone to deterioration due to prolonged use, so timely replacement is essential. Vehicles equipped with brake fluid level warning devices should monitor whether the warning light flashes and if the sensor is functioning properly. When the brake fluid is low, it should be replenished promptly, and stored brake fluid should be maintained between the calibrated minimum and maximum capacity marks. If braking becomes inconsistent during normal driving, the brake fluid should be replaced immediately. Before replacement, clean the braking system thoroughly with alcohol. If the vehicle pulls to one side during braking, conduct a comprehensive inspection of the braking system. If the wheel cylinder rubber cups are excessively swollen, it may indicate poor-quality brake fluid. In such cases, opt for higher-quality brake fluid for replacement and replace the rubber cups simultaneously. During seasonal changes, especially in winter, if braking performance declines, the brake fluid grade may not be suitable for winter conditions. When replacing the fluid, choose a brake fluid with lower viscosity at low temperatures. Avoid mixing different types and brands of brake fluids. For braking systems with special requirements, use the specified brand of brake fluid. Due to differing formulations among brands and types, mixing brake fluids can degrade performance. Even if certain brands claim compatibility or substitutability, their performance may still be unsatisfactory, so avoid long-term use. If water or impurities are found in the brake fluid, replace or filter it promptly to prevent insufficient braking pressure and compromised braking performance. Regularly replace brake fluid: The volume of brake fluid changes with temperature, so the fluid reservoir has a vent hole. Air drawn in through this hole may contain moisture or impurities, which can be absorbed or dissolved by the brake fluid, lowering its boiling point. During prolonged braking, the braking system heats up, potentially causing vapor lock as air is compressed, leading to reduced braking force or failure. For safety, brake fluid must be replaced periodically.