What is the method for bleeding brake fluid during a car brake fluid change?
2 Answers
The method for bleeding brake fluid during a car brake fluid change is: 1. Lift the vehicle using a lift and remove the rubber dust cap from the drain port; 2. Attach both ends of a transparent hose to the drain port and a waste oil collection bottle, then loosen the drain port screw counterclockwise with a wrench; 3. Repeatedly press the brake pedal, causing brake fluid to spray from the drain port. Once the fluid runs clear, tighten the drain port screw; 4. After repeatedly pressing the brake pedal, hold it down and loosen the drain port screw; 5. Once the brake fluid stops spraying, tighten the screw and release the brake pedal; 6. Repeat the above steps several times until no air bubbles are present in the discharged brake fluid.
When bleeding brake fluid, it's crucial to completely remove all air. I often do this job, and teamwork is safest. First, prepare new brake fluid, an open-end wrench, transparent tubing, and a small container. Start the car and let the engine idle with the master cylinder filled with new fluid. Have an assistant sit in the car to pump the brake pedal while you locate and open the bleeder valve at the wheel. When the pedal is pressed down, open the valve to expel old fluid and air bubbles. Close the valve when bubbles stop appearing, then release the pedal. Repeat this 4-5 times until the fluid runs clear and bubble-free. Start with the wheel farthest from the master cylinder (usually right rear), then left rear, right front, and left front. Never let the master cylinder level drop too low - keep adding fresh fluid to prevent air ingress. Wear gloves as old fluid can corrode skin, and dispose of waste fluid at an auto shop. After finishing, pump the brakes to test pedal feel before driving.
