With the dead point (engine speed lower than approximately 700rpm), the clutch is disengaged (60 to 65kg/cm2 in the clutch cylinder) the automatic clutch piston is lowered and the pressure in the cylinder becomes equal to P1 (see # clutch cylinder).

Example: 1st. Starting the car (see Pl.31)

Placing the gear lever in first moves the selector piston, which passes fluid under pressure to:

- the selector fork cylinder: the selector shaft slave piston advances - consumption of fluid under pressure.

The pressure, increasing at the end of the fork's movement, becomes sufficient to raise the valve corresponding to 1st gear. The valve actuates the gear changing piston:

- Lowering pressure in the clutch cylinder: "slip"

- When accelerating: progressive clutch engagement.