What is the water content of brake fluid?
3 Answers
Under normal circumstances, the water content of 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 of the brake fluid reaches 7-8%, the boiling point of the brake fluid will decrease by more than 50%. The relevant content about brake fluid is as follows: Introduction to brake fluid: Brake fluid is also known as hydraulic brake fluid. The water content of brake fluid has a certain proportion, and when the water content is too high, it must be replaced promptly. Brake fluid itself has hygroscopic properties, and moisture in the air can seep in through the vent holes of the brake fluid reservoir. Over time, this can lead to excessive water content in the brake fluid. 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.
Excessive moisture in brake fluid is unacceptable, typically it should be kept within 3%-4% for safety. I've encountered many car owners neglecting this—water content drastically lowers the boiling point. Once it exceeds the standard, braking at high speeds becomes as soft as cotton, risking slippage in critical moments. Testing is straightforward with a dedicated pen; if readings are high, replacement is necessary. Regular checks every two years not only prevent accidents but also protect the entire system. Long-term exposure to air leads to moisture buildup; ignoring it increases wear and can lead to shocking repair costs. Make it a habit to check fluid levels—don't wait until bubbles appear at a red light to regret it.
The water content in brake fluid should be below 3%-4%, as higher levels can impair performance. From years of driving experience, I've learned that excessive moisture easily vaporizes and forms bubbles, leading to brake failure. This is especially problematic during rainy seasons or long-distance driving. I recommend keeping a testing tool handy—it only costs a few dollars. If the reading exceeds the limit, replace the fluid immediately. This is directly related to safety; small oversights can cause major issues. Check the fluid level and condition every two years to avoid trouble. Remember, good brake fluid ensures crisp, reliable stopping power for smooth journeys.
