GF42.25-W-3003A | Brake application with trailer braking, 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, 954.0 /1 /2 with CODE (BB1) Brake control (BS)
MODEL 950.0 /1 /2 /3, 952.0 /1 /2 /3, 953.1 /3, 954.0 /1 /2 with CODE (BB8) Brake control (BS) with ASR
W42.25-0013-12
1.1 Proportioning valve
1.2 Pressure sensor
1.3 Relay valve
13.05 Brake value sensor
14.02 Parking brake valve with trailer control
16.07 Proportioning relay valve
18.07 Trailer control valve
33.06 Redundancy valve
35.02 Coupling head for supply
35.03 Coupling head for brake
V1 Supply, circuit 1
V2 Supply, circuit 2
V3 Supply, circuit 3
a Supply pressure (V1, V2 and V3)
b Redundancy circuit (pneumatic control pressure)
c Brake circuit
The maximum supply pressure is available at the brake value sensor (13.05) and the trailer control valve (18.07).
When the brake pedal is depressed, the brake value sensor (13.05) measures the pedal travel and relays it to the BS/EPB control unit. In addition, the brake light switches are closed, indicating to the BS/EPB control unit that the brake lights must be actuated.
When the brake value sensor (13.05) is operated, the trailer control valve (18.07) is actuated electrically and supplies pressure to the brake coupling head (35.03) according to the defined specification. Simultaneously the pneumatic control pressure modulated by the brake value sensor is also present at connection 42 of the trailer control valve.
The wheel speed sensors provide the BS/EPB 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 electropneumatic system, the redundant (pneumatic) control pressure modulated by the brake value sensor (13.05) actuates the trailer control valve via connection 42.