What is the operation process for replacing brake fluid?
2 Answers
The operation process for replacing brake fluid is: 1. Use a machine to suck out the brake fluid from the drain nut, then continuously add new brake fluid to the reservoir and repeat the operation; 2. Continue until the discharged brake fluid is clear and free of air, then use the same method to replace the brake fluid for the remaining three wheels. Brake fluid, also known as hydraulic fluid, should be purchased from reliable manufacturers, and the higher the grade, the better. All liquids have the characteristic of being incompressible. In a sealed container or a pipeline filled with liquid, when the liquid is under pressure, it quickly and uniformly transmits the pressure to all parts of the liquid. Hydraulic braking works based on this principle.
As an auto mechanic for many years, I frequently perform brake fluid replacement jobs. The entire process must be executed step by step: First, prepare tools including new brake fluid, a container, tubing, a wrench, and gloves. Safety first—find a level ground to lift and stabilize the vehicle's tires. Next, locate the brake master cylinder reservoir and remove some old fluid to prevent overflow. Then, follow the bleeding sequence starting from the point farthest from the pump—traditionally, the left rear wheel first. Loosen the bleeder screw, connect the tube to drain the old fluid into a bottle, wait until the flow clears or runs out, then tighten the screw. Repeat the same operation for the left front wheel, followed by the right front wheel and then the right rear wheel. Finally, ensure all screws are tightened securely without leaks. After draining, refill with new DOT4-type brake fluid, start the engine, and gently pump the brake pedal a dozen times to purge air bubbles. Check if the pedal is firm and doesn’t wobble. Once completed, test-drive at low speed to verify brake response and prevent accidents. Why this specific sequence? To avoid air remaining in the system, which could lead to brake failure. A vacuum pump can simplify the process for efficiency. Safety reminder: Wear goggles to prevent fluid splashes into the eyes. Replace the fluid every two years to prevent moisture corrosion and boiling point degradation hazards.
