How to Determine Brake Fluid?
4 Answers
Brake fluid can be seen on the exterior of the reservoir, which has markings. If the brake fluid is depleted, the brake warning light on the dashboard will illuminate. Here is relevant information about brake fluid: Methods for selecting brake fluid: 1. First, since the seals in the braking system are rubber components, prolonged immersion in brake fluid can cause chemical changes. 2. Second is the high-temperature performance, which refers to the brake fluid's ability to resist vapor lock at high temperatures. This is evaluated using the "equilibrium reflux point" metric. 3. Third is the low-temperature performance of the brake fluid, which refers to its flow characteristics at low temperatures. This is assessed by measuring the kinematic viscosity of the brake fluid at 40°C. If the viscosity is too high at this temperature, it can affect the transmission of braking force. 4. Fourth, since many components in the automotive braking system are made of metal, high-quality brake fluid should contain various anti-corrosion additives to prevent corrosion of the braking system.
I've been driving for over a decade. How to check brake fluid condition? First observe the color – new fluid is usually light yellow or clear. If it turns cloudy or black, it means there's excessive moisture or contaminants, requiring replacement. Secondly, regularly use a brake fluid tester to measure moisture content at the reservoir opening. If it exceeds 3%, replacement is needed because water lowers the boiling point, risking brake failure during high-temperature operation. I personally check annually and watch for symptoms like spongy brake pedal or no response when fully depressed, which may indicate degraded fluid quality. After car washes or rain, pay extra attention to the reservoir cap seal to prevent bubbling and system corrosion. Finally, recommend testing every two years or 30,000 km – don't neglect minor issues, as brake failure on highways could be disastrous.
As a safety-first driver, I believe assessing brake fluid is crucial. During every maintenance session, I have the technician check the moisture content—it's simple, using a tester to measure the boiling point, which should normally be above 260°C to be considered safe. You can also inspect the color change of the fluid at home; if it turns from transparent to dark brown, it indicates oxidation and should no longer be used, otherwise, braking distance increases and danger doubles. Don’t forget to check the fluid level with the dipstick—if it’s too low or has foam, it’s a sign of system leakage. I recommend a quick test every six months, especially before long trips, combined with symptoms like unusual noises or vibrations for a comprehensive analysis. Brake failure is a serious issue—early detection and fluid replacement save both peace of mind and money.
For daily driving, I judge the brake fluid based on two points: color and feel. The fluid is originally clear, and if it turns dark or foamy, it's about to go bad. When washing the engine, I usually take a quick look at the fluid reservoir's condition and clean it if it's dirty. Generally, the fluid should be replaced every 30,000 kilometers or every two years, otherwise, the brake pedal might feel spongy and lack power when pressed. For testing, you can use a test strip to dip into the fluid and observe how quickly the color changes—it's simple and convenient. In short, keep up with regular checks and don't wait until the vehicle inspection to address any issues.
