Emergency Brake Mode, Function - GF42.22-P-1003RFH

Model 205.012/013/047/053/054/147/212/213/247/253, 

Model 253.353/354/953/954/99 

Emergency braking mode, general 

The emergency braking mode describes the hydraulic safety circuit. At the front axle, the brake pressure continues to be generated hydraulically via the master brake cylinder, as also in the case of fault-free operation.

In the event of a fault, the rear axle switchover valve (A7/3y19) is not actuated. The rear axle brake circuit (secondary circuit) thus remains hydraulically connected to the master brake cylinder. The driver uses pedal force to generate the desired brake pressure at the rear axle, like in case of a conventional brake system.

The pedal force of the driver is assisted by the brake booster BAS (A7/7). The distribution of the brake pressure to the front and rear axles is realized by a brake pressure distribution facility that is installed in the traction system hydraulic unit (A7/3).