Note. The fluid used in the hydraulic circuit of the brake system is highly toxic and chemically aggressive. Try to avoid getting brake fluid in your eyes and on painted surfaces of body panels. In addition, brake fluid is highly hygroscopic, so it is unacceptable to use it after long-term storage in an open container. Excessive moisture content can significantly reduce braking efficiency.
1. The procedure is similar to that described in Chapter Brake system for bleeding the brake system, with the caveat that the brake master cylinder reservoir must first be emptied using a syringe or rubber bulb.
2. Open the bleed valve of the caliper/wheel cylinder of the first brake mechanism in order (see Chapter Brake system), then pump out the brake fluid present in the master cylinder by pressing the foot brake pedal several times smoothly.
3. Top up the reservoir to the MAX mark and repeat bleeding until the brake fluid is completely replaced (fresh fluid should start flowing out of the valve). Tighten the valve and fill the tank again to the maximum mark.
Note: Old brake fluid is usually noticeably darker in color than fresh fluid, so the procedure should not be too difficult.
4. Repeat the procedure for each of the remaining calipers/wheel cylinders in turn - make sure that the fluid level in the master cylinder reservoir does not fall below the MIN mark to avoid air being sucked into the system, which can significantly increase the time and effort required.
5. After completing the procedure, make sure that the bleeder valves are securely tightened. Don't forget to put the protective caps on the valves. Collect all traces of spilled brake fluid and check the level in the master cylinder reservoir again.
6. Before operating the vehicle, make sure that the brakes are functioning properly.