2. Loosen the nuts of the brake hydraulic lines on the master cylinder (see photo).
3. Loosen the bolts securing the shut-off valve/drain cock, remove the bracket. Disconnect the brake lines from the master cylinder and plug the holes to prevent dirt from entering.
4. Unscrew the two nuts securing the master cylinder, move aside the bracket with the shut-off valve and drain cock (see photo). Remove the master cylinder.
5. Remove the tank cap and diaphragm, drain the remaining liquid.
6. Place the master cylinder in a vice.
7. Remove the primary chamber piston retaining ring by pushing the piston back and prying the ring off with a screwdriver (see photo).
8. Remove the primary chamber piston with spring from the cylinder (see photo).
9. Remove the secondary chamber piston from the cylinder. If necessary, turn the cylinder over and tap the piston against a wooden block to remove it (see photo).
10. Pry and remove the tank from the cylinder body (see photo). Remove the seals.
11. It is not permitted to remove the bypass valve from the cylinder body, since this device is non-disassemblable and cannot be serviced.
12. Check the condition of the cylinder. If any damage is found, replace the master cylinder. Grinding the inner surface is not allowed.
13. Lubricate the new reservoir seals with brake fluid and press them into the cylinder body. Make sure the seals are in place.
14. Place the reservoir on a hard surface and press it into the master cylinder body (see photo).
15. Remove the old secondary chamber piston seals and install new seals with the lips facing away from each other (see photo). The secondary piston main seal must be oriented as shown in the photo.
16. Install a new spring thrust washer onto the secondary chamber piston (see photo).
17. Lubricate the cylinder with clean brake fluid and install the spring and piston of the secondary chamber with seals (see photo).
8.17. Brake master cylinder parts.
1. Feed tank with lid, diaphragm
2. Seals
3. Retaining ring
4. Primary chamber piston with spring
5. Secondary chamber piston with spring
6. Body
18. Install the primary chamber piston with the spring into the cylinder, press the piston back and insert the retaining ring.
19. Check the tank cap and diaphragm. If cracks or deformations are found, replace the tank. Secure the diaphragm to the tank cap.
20. Before installing on the vehicle, remove air from the cylinder, which will speed up bleeding of the brakes and save fluid.
21. Clamp the cylinder in a vice, fill the reservoir with fluid, tighten the plugs and press the primary chamber piston with a large Phillips screwdriver. Unscrew the plug to release air. Screw the plug back on and release the piston. Repeat these steps until fluid begins to flow out of the hole under the fitting. Maintain the fluid level in the reservoir at all times. Repeat the air removal steps for the other hole.
22. Instead of a plug, you can close the hole with your finger. Release your finger after pressing the pistons, after the liquid flows out, close the hole with your finger and release the pistons. After a few seconds, press the piston again and remove your finger. Repeat the procedure and do the same on the other hole. After only liquid begins to flow out of the holes, tighten the plugs.
24. Install the cylinder in the reverse order. First, tighten both nuts by hand. Screw in the fittings without distortions, manipulating the cylinder. Tighten the nuts and fittings.
25. When finished, remove air from the brake hydraulic system.