GF42.50-D-0001A | Vacuum-assisted hydraulic dual-circuit brake system, function | 9.1.01 |
MODELS 901, 902, 903, 904, 905
D42.50-1102-05
1 Vacuum pump
shown on engine 612.981
2 Brake booster
3 Brake master cylinder
The service brake at the wheels consists of a dual-circuit hydraulic brake system. A vacuum pump (1) flanged onto the engine produces a vacuum which boosts the actuating force applied by the driver during braking.
This vacuum acts on a vacuum chamber at the brake booster (2). Ambient air pressure presses on the working membrane on the side nearest the pedal corresponding to the force applied to the pedal by the driver. The vacuum created by the vacuum pump (1) acts on the opposite side of the membrane of the brake
booster (2).
The force on the membrane resulting from the difference in pressure contributes to the force applied to the pedal by the driver. A master brake cylinder (3) flanged onto the brake booster (2) actuates the booster via a thrust rod and converts the displacement of the thrust rod into hydraulic pressure. This hydraulic pressure is guided in a dual circuit via the brake lines and actuates the individual wheel brakes. The clamping force of the brake pads and thus the braking of the vehicle depends on the pressure in the brake system.