How to Determine if Brake Fluid Needs Replacement?
2 Answers
Methods to determine if brake fluid needs replacement are: 1. Open the brake fluid reservoir cap; if the brake fluid appears cloudy or black, it needs to be replaced; 2. Drive at a normal speed above 40km/h and then brake hard; if the braking distance is significantly longer, replacement is required; 3. If the brakes feel soft or unstable during normal driving, replacement is needed. The reasons for replacing brake fluid are: 1. Moisture or impurities from the air can enter through the reservoir's vent hole, lowering the boiling point of the brake fluid; 2. During prolonged braking, the brake lines can develop vapor lock, leading to reduced braking force or brake failure. The functions of brake fluid are: 1. Brake fluid has a very low freezing point, ensuring good fluidity at low temperatures; 2. Brake fluid has an extremely high boiling point, preventing vapor lock at high temperatures; 3. It does not cause corrosion to metal or rubber.
I've been driving for a while, and I feel that judging whether the brake fluid needs to be changed starts with looking for clues in actual driving. For example, if the brake pedal feels softer than before when pressed, or if you need to exert more force to stop the car, it might be a sign that the fluid has aged. It's best to regularly pop the hood and check the small fluid reservoir: new fluid is clear and yellowish, shiny like honey; but if it turns dark brown or looks dirty, like old coffee grounds, then it's time for a change. Another method is to give it a sniff—bad fluid has a strange odor. I recommend checking it every two years or 40,000 kilometers; don't wait until something goes wrong to panic. In humid areas where the car is driven frequently, the fluid is more prone to absorbing moisture, lowering its boiling point and reducing braking efficiency, which poses risks during high-speed driving. So, paying more attention can ensure safety.
