
Originally Posted by
Memphis Raines
Bleeding the brakes is when you flush air that may be found in the brake fluid line.
Usually, we replace the brake fluid itself during the process which is essential maintenance. The mechanic may ask you to pump the brake pedal several times and lets you hold it. The mechanic then opens the bleeder valve to let out fluid and air, then closes the valve after the pedal has set. This process is done to prevent air being sucked back in through the valve. The process is repeated as many times as needed for each brake.