The internal cavity of the master brake cylinder is divided by pistons into two separate chambers. Each of the chambers serves its own circuit. When you press the brake pedal, the pistons of the master brake cylinder begin to move, displacing fluid under pressure from the chambers into the brake pipes, and then into the wheel brake cylinders. Due to the fact that the chambers of the main brake cylinder are not communicated, when one of the circuits is depressurized, the second brake circuit remains operational.
Rear brake fluid pressure regulator: 1 - earring for fastening the elastic lever to the rear axle; 2 - retainer of the elastic lever in the earring; 3 - elastic lever; 4 - regulator mounting bracket; 5 - protrusion of the plate adjusting bracket; 6 - a bolt of forward fastening of a regulator; 7 - plate adjusting bracket; 8 - plate; 9 - lever; 10 - regulator; 11 - control hole closed with a plug; 12 - arrow on the body of the regulator, indicating the direction of fluid flow in the connected tube
The force applied to the brake pedal is increased by a vacuum booster that uses the vacuum created in the receiver when the engine is running. If the engine stalls while the vehicle is moving, much more force will have to be applied to the brake pedal to stop the vehicle.
The tubes going to the working cylinders of the rear brake mechanisms pass through the pressure regulator. When braking hard, there is an increase in the load on the front axle of the car and a decrease in the load on the rear axle. At the same time, the traction of the front wheels improves, and the rear wheels deteriorate, and they are easily blocked, which makes the rear axle of the car prone to skidding. To prevent this from happening, the pressure regulator, when unloading the rear axle, limits the fluid pressure in the rear brake cylinders and prevents their instant blocking.
In the body of the regulator there is a control hole closed with a plug. Leakage of fluid from this hole indicates a leak in the cuffs of the regulator and the need to repair or replace it.