What is the purpose of brake fluid?
2 Answers
Brake fluid is used in hydraulic brake booster pumps as a force transmission medium. The brake pedal pushes the piston of the master cylinder, which then applies force to the brake fluid. Since the oil pipes can be arranged flexibly, it facilitates the layout of the braking system. Subsequently, the pressure of the brake fluid acts on the wheel cylinders, which then push the braking components to generate braking force. Hydraulic clutches operate on the same principle. Brake fluid is toxic and highly corrosive, and should not come into contact with paint. Brake fluid is hygroscopic, meaning it can absorb moisture from the surrounding air, so it should be stored in a sealed container. When brake fluid absorbs moisture, its braking effectiveness diminishes, so it should be replaced regularly.
Brake fluid is essentially the lifeblood of the braking system, responsible for transmitting the force from your foot to the brake calipers on all four wheels. I've seen many car owners who think replacing it makes no noticeable difference, but what they don't realize is that it's highly susceptible to moisture absorption and degradation. Over time, water contamination can lead to vapor lock during high-temperature braking, causing a spongy pedal or even complete failure. That's why regular replacement is absolutely crucial—I recommend checking and changing it every two years or 40,000 kilometers, especially in humid southern regions. During replacement, make sure the mechanic thoroughly bleeds the air from the system, otherwise your brakes will feel like stepping on cotton—a potentially deadly scenario when it matters most.
