When bleeding the brakes, air may be trapped in the brake lines or valves far upstream, as much as 10 feet from the bleeder screw. Therefore, it is very important to have a fast flow of a large volume of brake fluid when bleeding the brakes, to make sure all of the air is expelled from the system.
To bleed the brakes, proceed as follows.
- Remove the old brake fluid from the reservoir using a siphon gun or a baster and clean the brake master cylinder reservoir with a clean lint-free cloth. If necessary, remove the reservoir and flush out with brake cleaner.
- Bleed the brake system at each fitting. Do NOT proceed to the next fitting until all air bubbles are removed from the previous fitting. Bleed the brakes, making sure to following this sequence:
- Attach a clear plastic hose to the bleeder screw, then place the hose into a clean jar that has enough fresh brake fluid to submerge the end of the hose.
- Have an assistant pump the brake pedal ins a smooth, easy fashion, 3-4 times, and hold it down keeping pressure on it, then open the bleeder screw at least 1 / 4 turn. When the bleeder screw opens, the brake pedal may drop further and should be kept pressed down. Have the assistant hold it there until the bleed valve is closed.
- Close the bleeder valve and have the assistant slowly release the brake pedal only AFTER the bleeder valve is closed, then check the master cylinder fluid level and top off as necessary.
- Repeat the bleeding procedure until all there are no air bubbles, or a minimum of 4 or 5 times at each bleeder screw, then check the pedal for travel and feel. If the pedal travel is excessive, or feels spongy, it's possible enough fluid has not passed through the system to expel all of the trapped air.
- Once completed, pump and check the brake pedal for a firm feel, then, if the pedal pressure is firm, test drive the vehicle to be sure the brakes are operating correctly and that the pedal feel is firm during braking.