The upper surface of yellow cup at its lowest position is lower than the liquid surface in the tank. So the cup is filled fully with the liquid.
Turn pink cam to raise the cup to its highest position to get:
1. The coincidence of cross holes on the orange bar and on the blue support.
2. The upper surface of yellow cup is higher than the liquid surface in the tank.
Then the liquid amount contained in the cup flows out through green pipe (red arrow). The red line shows liquid surface in the cup.