The structure and operating principle of the master brake cylinder (VAZ-2101)

The main brake cylinder is attached to the clutch and brake pedal bracket. Pistons 3 and 4 (Fig. 136) activate different circuits. Both pistons take their initial position under the action of springs 7. The movement of the pistons under the action of the springs is limited by screws 6. The tightness of the pistons in the cylinder is ensured by four sealing rings 5. The housing 2 of the cylinder is closed at the front by plug 1.



In the initial position of the pistons in the cylinder, the spacer rings 9 rest against the screws 6. In this case, the sealing rings 5 move away from the end surface of the piston grooves and through the resulting gaps, the working cavities of the cylinder are filled with liquid from the tank.

When the pedal is pressed, the pusher moves the piston 4 forward (to the left). The spacer ring 9 stops pressing on the sealing ring 5, and it, pressed under the action of the spring 8 to the end of the piston groove, separates the tank cavity from the cylinder cavity. This ends the free travel of the piston, which on the brake pedal is 3-5 mm.

With further movement of piston 4, the fluid pressure in the cavity of the drive of the front wheel brake mechanism circuit increases and under its action, piston 3 of the drive of the other circuit moves. With serviceable circuits, the pressure in both working cavities of the cylinder will increase equally.

(The original can be viewed on the portal: VAZBOOK.ru)