Brake Master Cylinder Air Detection Without a Test Valve

The patent extracts the air detection function from the test valve and implements it using the existing pressure sensor that is already part of the brake system. The pressure sensor measures brake master cylinder pressure during actuation, and air presence is detected by analyzing whether the pressure increases sufficiently when the master cylinder is actuated with closed isolation valves. This eliminates the need for a separate test valve while maintaining air detection capability.

The pressure sensor serves multiple functions: it monitors brake master cylinder pressure during normal braking operation and simultaneously detects air presence by analyzing pressure changes during specific actuation sequences. This multi-functionality eliminates the need for dedicated test valve hardware while providing both safety monitoring and diagnostic capabilities.

The system automatically performs air detection by utilizing the existing brake actuation mechanism. When the driver presses the brake pedal, the master cylinder actuates and the pressure sensor automatically measures the pressure. The control unit analyzes the pressure data to detect air presence. This self-service approach eliminates the need for manual isolation valve operation by the user, as the system performs detection during normal braking operation.

The control unit is pre-programmed with the expected pressure characteristics for air-free and air-containing conditions. During brake actuation, it automatically compares the measured pressure against these pre-stored reference values to determine air presence. This preliminary preparation of reference data enables automatic detection without requiring manual isolation valve manipulation.