Master brake cylinder
1 - adapter with three tubes; 2 - adapter with two tubes; 3 - the main brake cylinder; 4 - gasket; 5 - vacuum brake booster
Removing
1. Disconnect the electrical connector from the brake fluid reservoir.
2. Remove the brake reservoir cap and use a syringe to draw out the brake fluid.
3. Mark the brake pipes suitable for the main brake cylinder. Position a clean rag under the brake master cylinder. Unscrew nuts of fastening of brake tubes and take brake tubes aside from the main brake cylinder. Close the ends of the tubes with appropriate plugs.
4. Unscrew nuts of fastening and remove the main brake cylinder from the vacuum amplifier of brakes together with a lining.
Repair
Details of the main brake cylinder (top without ABS, bottom with ABS)
1 - the body of the main brake cylinder; 2 - sealing ring; 3 – the screw of fastening of a tank of a brake liquid; 4 - plug; 5 - mesh filter; 6 - brake fluid reservoir; 7 - sealing ring; 8 - retaining ring; 9 - piston and spring No. 1; 10 - piston and spring No. 2; 11 - gasket; 12 - locking bolt; 13 - locking bolt; 14 - gasket; 15 - sealing ring; 16 - screw for fastening the brake fluid reservoir; 17 - cork; 18 - mesh filter; 19 – brake fluid reservoir; 20 - sealing ring; 21 - retaining ring; 22 - piston and spring No. 1; 23 - piston and spring No. 2; 24 - the body of the main brake cylinder
1. Unscrew a bolt of fastening of a tank.
2. Remove the brake fluid reservoir and o-rings.
3. Fix the main brake cylinder in a vise and, using a suitable mandrel, press the pistons of the main brake cylinder against the stop and unscrew the lock bolt.
4. Remove the circlip at the end of the brake master cylinder.
5. Remove the pistons and springs from the brake master cylinder housing.
6. Wash all parts of the brake master cylinder in brake fluid and check the condition of the parts. Before installing the parts in the master brake cylinder, pre-lubricate them with clean brake fluid.
7. Install the pistons with springs in the brake master cylinder, move them all the way forward and tighten the locking bolt.
8. Install a new retaining ring at the rear of the brake master cylinder.
9. Establish sealing plugs of a reservoir of a brake liquid, a reservoir and fix a reservoir with the screw.
10. Before installing the master brake cylinder, fill it with brake fluid and remove air, for which fix the master brake cylinder in a vice and close the outlet holes of the master brake cylinder with threaded plugs.
11. Fill the reservoir with clean brake fluid.
12. Unscrew one stopper and, moving the piston in the main brake cylinder, squeeze out air from it.
13. Screw the screw plug back in before releasing the piston.
14. Repeat the bleeding operation until only clean brake fluid comes out of the hole without air bubbles. Repeat the operation to remove air from the brake master cylinder at the second outlet.
Installation
1. Install the brake master cylinder to the brake booster struts and secure with nuts, hand-tight at this stage.
2. Unscrew the screw plugs from the main brake cylinder and screw the brake pipes in their place.
3. Finally tighten the brake master cylinder nuts.
4. Remove the air from the brake master cylinder that got there when installing the brake pipes. Press the brake pedal sharply, unscrew the nut securing the brake tube to the brake master cylinder by half a turn while pressing the pedal. By continuing to press a pedal, force out the liquid which is in system together with air. After the pedal has reached its frontmost position and fluid has stopped flowing out, tighten the pipe nut. Repeat these operations until the release of air from the master brake cylinder stops.