What are the hazards of excessive water content in brake fluid?
2 Answers
Normally, the water content in brake fluid is below 1%. If it is too high, it will lower the boiling point of the brake fluid, causing the brake fluid to boil and vaporize during high-intensity braking, leading to brake failure. When the water content in the brake fluid reaches 3%, the boiling point of the brake fluid will decrease by 25%; if the water content in the brake fluid reaches 7-8%, the boiling point of the brake fluid will decrease by more than 50%. The relevant information about brake fluid is as follows: Introduction to brake fluid: Brake fluid is also known as hydraulic brake fluid. The water content in brake fluid has a certain proportion, and when the water content is too high, it must be replaced promptly. Brake fluid itself is hygroscopic, and moisture in the air can seep in through the vent hole of the brake fluid reservoir. Over time, this can cause the water content in the brake fluid to exceed the standard. Function of brake fluid: It can effectively lubricate the moving parts of the braking system, extending the service life of the brake calipers and rubber cups.
I once encountered the issue of brake fluid with excessive water content during a long-distance drive. That time, emergency braking on a mountain road nearly caused an accident. Water in the brake fluid lowers its boiling point, and when you press the brake, the fluid temperature rises and boils, creating bubbles in the system. The result is a spongy brake pedal, or even complete loss of braking power, which is as dangerous as playing with your life. Water also corrodes brake lines and pistons, leading to leaks or seizing over time, and repairs can be costly. Later, I bought a moisture test pen to check regularly. If the water content exceeds 3%, it's time to change the fluid, usually every two years. Also, if the fluid looks cloudy or thinner than usual, it's a warning sign. Don’t be lazy—safety comes first. Saving a little money isn’t worth the risk.
