GF42.25-W-3000B | Brake application at front axle, function | 18.6.07 |
MODEL 944, 950.5 /6, 952.5 /6, 953.6, 954.5
with CODE (BB1) Brake control (BS)
except CODE (ZX2) EPB II
MODEL 944, 950.5 /6, 952.5 /6, 953.6, 954.5
with CODE (BB8) Brake control (BS) with ASR
except CODE (ZX2) EPB II
MODEL 950.0 /1 /2 /3, 952.0 /1 /2 /3, 953.1 /3, 954.04 /05 /06 /08 /1 /2 with CODE (BB1) Brake control (BS)
MODEL 950.0 /1 /2 /3, 952.0 /1 /2 /3, 953.1 /3, 954.04 /05 /06 /08 /1 /2 with CODE (BB8) Brake control (BS) with ASR
W42.25-0015-06
1.1 Proportioning valve
1.2 Relay valve
12.07 Brake wear sensor
12.08 Rpm sensor
13.05 Brake value sensor
16.07 Proportioning relay valve
20.02 Single-circuit diaphragm brake cylinder
45.01 ABS solenoid valve
V1 Supply, circuit 1
V2 Supply, circuit 2
a Supply pressure (V1 and V2)
b Redundancy circuit (pneumatic control pressure)
c Brake pressure
The maximum supply pressure is available at the brake value sensor (13.05) and the proportioning relay valve (16.07).
When the brake pedal is depressed, the brake value sensor (13.05) measures the pedal travel and relays it to the control unit. In addition, the stop lamp switches are closed, indicating to the control unit that the brake lights must be actuated.
The BS/EPB control unit then actuates the proportioning relay valve (16.07) such that the calculated brake pressure is sent to the single-circuit diaphragm brake cylinders (20.02) via the ABS solenoid valves (45.01).
The wheel speed sensors (12.08) provide the control unit with feedback on the achieved braking effect and the wheel slip. This feedback is used in conjunction with the position of the brake pedal to regulate the brake pressure precisely.
In the event of a fault in the electronics system, the redundant (pneumatic) control pressure from the brake value sensor (13.05) actuates the relay valve (1.2) in the proportioning relay valve (16.07).