Solenoid Valve

The active element of the brake servo is the solenoid valve, which is supplied with current by the SBA control unit in by-wire mode. The activation of the solenoid valve allows air to flow into the work chamber of the active brake servo, which moves the linkage and exerts a force on the tandem brake master cylinder. Thus brake force can be built up in the hydraulic brake system without mechanical actuation by the driver.