Which instruction is important regarding mixing brake fluids?

The instruction to not mix brake fluid with other fluids is critical due to the potential chemical reactions that can occur. Different types of brake fluids are formulated with specific chemical compositions, and mixing them can lead to reduced boiling points, increased moisture absorption, and even damage to the brake system components. For example, if a glycol-ether based brake fluid (like DOT 3 or DOT 4) is mixed with a silicone-based fluid (like DOT 5), it can cause the brake fluid to lose its effectiveness and create significant safety hazards.

Additionally, mixing brake fluid with other automotive fluids, like power steering fluid or engine oil, can introduce contaminants that compromise the performance and safety of the braking system. This is why the guidance to avoid mixing brake fluids is emphasized in vehicle maintenance protocols. Keeping the brake fluid type consistent helps ensure proper function and longevity of the braking system.