Should Brake Fluid Be Replaced When Water Content Reaches 4%?
2 Answers
Normally, the water content in brake fluid should be below 1%. If it is too high, it will lower the boiling point of the brake fluid, causing the fluid to boil and vaporize during high-intensity braking, which can lead to brake failure. When the water content in brake fluid reaches 3%, the boiling point of the brake fluid will decrease by 25%. If the water content reaches 7-8%, the boiling point will drop by more than 50%. Here are some details about brake fluid: Introduction to Brake Fluid: Brake fluid is also known as hydraulic brake fluid. The water content in brake fluid has a certain limit, and when it exceeds this limit, the brake fluid must be replaced promptly. Brake fluid naturally absorbs moisture, and over time, water from the air can seep into the brake fluid reservoir through the vent hole, leading to excessive water content in the brake fluid. Functions of Brake Fluid: It effectively lubricates the moving parts of the braking system, extending the service life of brake calipers and rubber cups.
As an experienced driver who has driven for many years, I have encountered similar situations where the brake fluid's water content reached 4%, which is a dangerous sign. The standard is that it should be replaced if it exceeds 3%, because water mixed in lowers the boiling point. During long-distance driving or sudden braking, the fluid temperature rises, making the brakes feel spongy and increasing the risk of accidents. I remember one time when my car's brake response was sluggish, and upon inspection, the water content was found to be 4.5%. If I hadn't replaced it in time, it could have led to an accident. Spending a small amount of money to replace the fluid made it much safer. I usually recommend using a test pen to check the water content—it's inexpensive and something you can do yourself. Don't wait until the brakes fail to regret it. Safety comes first, so go to a repair shop and get it replaced as soon as possible. It affects not only your safety but also that of others on the road. In the long run, avoiding major repair costs is more economical.
