Brake fluid is known today as the standard DOT3 , DOT4 and so on , are made of basic materials that absorb water and water vapor ( humidity ) or also called hygroscopic . This causes the water content in brake fluid increases with time.



In the standard DOT3 brake fluid with water content as much as 3 % can occur in just one year and has been able to lower the boiling point of 205° Celsius to 145° Celsius only ! It means the brake fluid will boil easier . We know that the water has a boiling point of 100 degrees Celsius . This means that the water content in brake fluid will boil first and turns into water vapor that air bubbles form.


Air bubbles are very dangerous because of the ability to channel the brake fluid pushing the brake pressure will be reduced . Yet we know that the performance of the braking system is highly dependent on the ability of pressing the brake fluid canvas . This resulted in us having pressed the pedal harder and we might even just stepping on the air while the canvass was not working . This is what we call symptoms of brake failure.


So we should get used to drain the brake fluid once a year or every 20,000 km on the car and every 10,000 Km on the bike . Well as to clean and inspect the condition of seals , piston and brake calipers . It is not costly but can save our lives.