How Many Liters of Brake Fluid Should Be Replaced at One Time?
2 Answers
Generally, only 1L of brake fluid is needed for a replacement. It is essential to use brake fluid of the same grade as the original. The brake fluid grade is indicated on the brake fluid cap. For example, if the original fluid is DOT4, only DOT4 should be used. When replacing brake fluid, pay attention to the replacement interval, which varies depending on the climate. Additionally, the choice of brake fluid is crucial—always use the same grade, and avoid mixing different brands. Brake fluid is the liquid used in hydraulic brake systems. It must be chemically inert, resistant to high temperatures, and must not corrode, soften, or expand metal and rubber components. Common grades include DOT3, DOT4, and DOT5.
I've changed brake fluid multiple times myself, and experience tells me the amount needed for one change is between 0.5 liters to 1 liter, depending on the vehicle model. For compact cars like the Civic, about 0.6 liters is sufficient, while larger SUVs like the Tiguan require close to 1 liter. The key isn't the quantity but completely draining the old fluid before adding new one, as residual impurities can affect braking performance. Brake fluid absorbs moisture, lowering its boiling point over time, which can lead to soft brakes or failure. I change it every two years or every 40,000 kilometers. If doing it yourself, you'll need someone to help pump the brake pedal to bleed the system and ensure no air bubbles remain. Safety comes first, as this affects stopping distance and accident prevention—never cut corners to save money.
