What is the method for replacing brake fluid?
3 Answers
The method for replacing brake fluid is: 1. Open the car hood and locate the brake fluid reservoir; 2. Remove the reservoir cap and use a syringe to extract all the old brake fluid; 3. Add new brake fluid. The reasons for replacing brake fluid are: 1. Moisture or impurities from the air can enter through the reservoir vent, lowering the boiling point of the brake fluid; 2. During prolonged braking, the brake lines can develop vapor lock, leading to reduced braking power or brake failure. The functions of brake fluid are: 1. Brake fluid has a very low freezing point, ensuring good fluidity in cold conditions; 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 components.
I've been changing brake fluid for over a decade, and the key lies in tools and procedure. Just prepare new brake fluid, hoses, containers, and wrenches – make sure the specs match your vehicle manual, don't buy randomly. For example, don't mix DOT4 with DOT3. First, lift the car or park it level, open the hood to locate and clean the master cylinder cap to prevent dust contamination. A two-person operation works best – one pumps the brake pedal while the other bleeds, starting from the right rear wheel, then left rear, right front, and left front in sequence. With each full pedal press, drain old fluid into the container while topping up the master cylinder to keep levels above the MIN mark (air ingress causes spongy brakes – extremely dangerous). Never mix old and new fluid types to avoid system corrosion. After replacement, thoroughly bleed air and test brake pedal firmness. Regular changes are critical – moisture absorption lowers boiling points, risking brake fade during high-speed stops. I've witnessed accidents caused by neglected fluid changes in older cars!
I remember my first DIY brake fluid change didn't involve much preparation based on online tutorials. First, I bought the appropriate new fluid, with the tools being just a hose and container, plus needing a friend to help pump the pedal. The process was relatively simple: park and turn off the engine, clean the master cylinder, locate the bleeder valves on the wheel hubs, connect the hose to drain the old fluid into a container. One person pumps the brakes three to four times while the other releases the fluid, repeating until the old fluid is completely replaced by clear new fluid. Keep adding new fluid to the master cylinder to avoid running dry, then bleed the system and test the brake sound and pressure. Beginners often make mistakes like mixing up the sequence or using the wrong fluid type—I once messed up, resulting in soft brakes that nearly caused an accident. My advice is to check the manual and prepare thoroughly before attempting DIY. If you're not confident, it's safer to go to a professional shop since brakes are a matter of life and death. Regularly changing the fluid every two years can prevent issues and save money.
