What is the Function of Brake Fluid?
2 Answers
Brake fluid functions by transmitting hydraulic pressure from the master cylinder to the wheel cylinders, where pistons are pushed out under the action of sealed rubber cups. This force is then applied to the brake discs and pads, enabling the braking function. Characteristics of brake fluid include: 1. Low freezing point: Ensures good fluidity in low-temperature conditions; 2. High boiling point: Prevents vapor lock formation under high temperatures; 3. Minimal quality degradation: Does not cause corrosion to metals or rubber. The replacement procedure for brake fluid is: 1. Position the vehicle over an inspection pit or lift it with a hoist; 2. Clean the drain port, remove the dust cap, loosen the drain screw, repeatedly depress the brake pedal until clear fluid emerges, then tighten the drain screw; 3. Refill with fresh brake fluid.
I remember one time when my car's brakes suddenly felt spongy, and later I found out it was time to change the brake fluid. This stuff is like the blood of the braking system—every time you press the brake pedal, it transfers the force smoothly to the brake pads on all four wheels. The biggest concern is high temperatures. Friction from the brake pads generates heat, and if the brake fluid has a low boiling point, bubbles can form under high temperatures, making the brakes feel dangerously soft, like stepping on cotton. It also hates moisture. Absorbing too much water lowers its boiling point, so you need to be extra careful during the humid rainy season in the south. I change it every 20,000 kilometers or every two years—it's not expensive, but safety is no small matter.
