When Should Brake Fluid Be Replaced?
3 Answers
Brake fluid should be replaced when it appears dirty, turns black, or the brakes feel spongy. The replacement method is as follows: 1. Lift the vehicle using a lift; 2. Remove the dust cap from the oil port; 3. Attach both ends of the hose to the oil drain port and the collection bottle; 4. Loosen the drain screw with a wrench while pressing the brake pedal; 5. Add brake fluid as the level drops until all the old fluid is drained; 6. Tighten the drain screw and check the brake fluid reservoir level. The working principle of brake fluid is based on the incompressible nature of liquids. In a sealed container or a pipeline filled with liquid, when pressure is applied, the liquid quickly and uniformly transmits the pressure to all parts of the liquid. Its functions include transmitting energy, dissipating heat, preventing corrosion and rust, and providing lubrication.
Changing brake fluid is actually quite common. After driving for so many years, I believe there are several situations where it really needs to be done promptly. First, over time, brake fluid becomes thicker after a year or two of use and absorbs moisture, lowering its boiling point. This can cause it to boil and form bubbles during hard braking, making the brake pedal feel spongy. Second, it depends on how much you drive—frequent braking in city traffic or long highway trips can accelerate fluid degradation. Third, during maintenance checks, if the technician uses a tool to measure moisture content exceeding 2%, or if the fluid color darkens or becomes cloudy, it’s time for an immediate change. Additionally, if you notice reduced braking responsiveness, longer stopping distances, or abnormalities like leaks or unusual noises in the system, don’t hesitate—check the fluid right away. I recommend following the manual’s advice to change it every two years or 20,000 kilometers. Neglecting this can lead to increased wear on the braking system, higher repair costs, and compromised safety. When it comes to driving, paying attention to details ensures peace of mind. Regularly check the fluid level in the reservoir—avoid overfilling or letting it run too low—and monitor the fluid color periodically. Don’t wait until problems arise to regret it.
When it comes to replacing brake fluid, I believe its primary purpose is to prevent safety hazards. Generally, manufacturers recommend changing it every two years or 30,000 kilometers. For experienced drivers like me who frequently take long-distance trips, encountering high temperatures or rainy, humid conditions can cause the fluid to absorb moisture, significantly lowering its boiling point. In emergency braking situations, this can lead to complete brake failure—how dangerous is that? Another scenario is during maintenance when the fluid appears yellow or black, or if a spot check reveals high water content. These are clear signs it needs immediate replacement. Delaying the change could damage the brake master cylinder or wheel cylinders, resulting in much higher repair costs. Additionally, if your car hasn’t had a fluid change in several years, or if you’ve just bought a used car and it’s your first maintenance check, it’s wise to test the fluid to avoid potential risks. I once experienced early signs of brake failure, and now I make it a habit to change the fluid regularly. Don’t skimp on this small expense—safety should always come first. A quick glance at the fluid reservoir before daily drives to ensure it’s clear and not murky gives me peace of mind.
