P42.31-0209-06
A7/7 BAS brake booster
b1 BAS diaphragm travel sensor
s1 BAS release switch
y1 BAS solenoid valve
a Vacuum piston
b Compression spring
c Power diaphragm
d Poppet valve
e Line connection for release switch and solenoid valve
f Air filter 2
g Air filter 1
h Output rod
i Vacuum fitting
Basic function as a normal brake booster.
An emergency stop is detected by the BAS control unit via the BAS diaphragm travel sensor (b1). In the case of a BAS brake application, the BAS solenoid valve (y1) opens valve (d), which admits atmospheric pressure from inside the vehicle via the air filters (g and f) to the rear of the power diaphragms (c).
The full assistance pressure from the brake booster is transmitted to the master brake cylinder via the output rod (h).
When the brake application is terminated, the control unit receives a signal from the BAS release switch (s1) and the BAS solenoid valve (y1) closes again. The BAS assistance is terminated.