How to Bleed Air After Adding Brake Fluid?
2 Answers
Method for bleeding air after adding brake fluid: 1. Lift the vehicle using a jack and secure it properly with jack stands, or drive it onto an inspection pit; 2. Three people are needed: the first person is responsible for loosening the air screws on the four-wheel brake calipers, the second person gets into the driver's seat ready to press the brake pedal, and the third person opens the engine hood, unscrews the filler cap of the brake fluid reservoir, and prepares to add brake fluid into the master cylinder container; 3. Loosen the bleeder screws on the four-wheel brake calipers, place a transparent plastic tube over the bleeder screw of each caliper, and put the other end of the tube into a container filled with brake fluid; 4. Continuously press the brake pedal until all the contaminated brake fluid is discharged; 5. While performing the above actions, continuously add new brake fluid into the container above the master cylinder, but do not let the brake fluid run out, as this would allow air to enter the brake lines, which would prolong the time needed to bleed the air from the lines; 6. After renewing the brake fluid, first tighten the bleeder screws on the four-wheel brake calipers, then proceed with the air bleeding process; 7. When bleeding air, first press the brake pedal 5 or 6 times continuously, then hold it down. At this point, immediately loosen the bleeder screw on the right rear wheel brake caliper and then quickly tighten it. Repeat this action until the brake fluid shoots out of the bleeder screw in a straight line (with strong jetting and no air bubbles).
I've been repairing cars for over ten years, and bleeding brakes is a pretty common task. After adding brake fluid, air can easily get into the brake system, making the brake pedal feel spongy and weak when pressed, which could even lead to accidents. That's why it's crucial to thoroughly bleed the system. The basic procedure requires two people working together: find a friend to help, with one person sitting in the driver's seat, pumping the brake pedal a few times until it firms up, then holding it down firmly; the other person uses a wrench to loosen the bleeder screw on the brake caliper, watching as fluid mixed with bubbles flows out, and tightening it back up once the flow becomes clean. Throughout the process, keep an eye on the brake fluid reservoir to ensure the level doesn't drop too low, or air will get sucked back in. I recommend starting with the front wheels first, then moving to the rear, repeating the process until the pedal feels firm. If you're doing it alone, you can buy a manual brake bleeder tool—it's more convenient but costs a bit. Be patient during the whole process and avoid being too rough to prevent damaging parts. Regular checks after changing the fluid are key to prevention; brake safety is nothing to take lightly.
