The depression created during the operation of the engine through a rubber hose and the backpressure valve 1 is transferred to A1 cavity. As A1 cavity through the central opening in a connector 22 and openings in a flange of a connector and the piston 10 is constantly reported with cavities of A3 and A5, in these cavities depression is also created.

When the pedal of a brake is not pressed, A5 cavity through a gap between a diaphragm of 18 valves, the piston 17 and radial openings of a connector 22 is reported with a cavity of A4 which, in turn, through A6 openings in a persistent cover is connected to A2 cavity. Therefore, in all cavities of A1, A2, A3, A4 and A5 of the amplifier depression is created.

The backpressure valve 1 holds the greatest depression which is formed during the operation of the engine in the amplifier.

By pressing a brake pedal the piston 17 under the influence of the pusher 16 connected with a pedal concerns a diaphragm of 18 valves and interrupts the message of cavities of A1, A3, A5 with cavities of A4 and A2. Then the piston 17, moving a diaphragm 18, tears off it from a saddle on the case of 15 valves. As a result atmospheric air, pass via the filter 14, openings in the case 15, comes to a diaphragm 18 and further through radial drillings in the case of 15 valves — to a cavity of A4 and through A6 openings in A2 cavity, that is to pistons 5 and 10. Atmospheric air comes to cavities of A4 and A2 until the diaphragm of 18 valves under the influence of a jet washer 20 does not sit down at the same time on saddles of the piston 17 and case 15, blocking intake of air. Thus, through a jet washer the watching action of system, i.e. the effort created by the amplifier, in direct ratio to the effort made by the driver for a brake pedal is carried out. At increase in effort to a pedal the piston 17 squeezes a jet washer 20, removes a diaphragm 18 from a saddle in the case of 15 valves and the additional amount of atmospheric air arrives to pistons 5 and 10 again that increases operation of the amplifier. The effort from a leg of the driver and from pistons 5 and 10 of the amplifier through a jet washer is transferred to a pusher 3 and further — to pistons of the main cylinder.

At a pedal otpuskaniye the piston 17 departs from a diaphragm 18, allowing it to move to a saddle in the case 15. In this case access of atmospheric air stops, and depression through the formed face gap between the piston 17 and a diaphragm 18 is transferred from A5 cavity to cavities of A4, A2. Cavities of A1, A2, A3, A4 and A5 will be reported among themselves again, and pistons under the influence of a spring 21 will return to a starting position and braking will stop. The amplifier is ready to new braking.

In case of an engine stop the depression kept in the amplifier by the backpressure valve allows to carry out 2 — 3 effective braking of the car. In the absence of vacuum in the amplifier, the pusher 3 will be influenced only by the effort made by the driver for a brake pedal.