Example 4th gear (Pl.33+28a, fig.4, with partial clutch engagement).
During braking - with partial and complete stopping of the vehicle - it is necessary to disengage the selected gear.
The gear change piston is kept in its high position, so it is not this which carries out the disengaging in this case. As the engine speed decreases, and consequently the weights of the centrifugal control move out, the gear change piston is moved, cutting the link between clutch cylinder and accumulator, releasing the pressure P1: DECLUTCHING (actually it will be P'1, see following paragraph).
The clutch corrector (placed at the end of the hydraulic part of the centrifugal regulator) is connected to the front right brake caliper.
With the foot brake applied, the fluid under pressure acts on the piston (p) which compresses the spring (t), consequently the spring (t') slackens and it's load decreases.
To compensate for some loss and in order to obtain the same state of balance of the automatic clutch piston, the pressure in chamber (f) becomes higher than P1, i.e. P'1.
Note: If P1 = 30kg/cm2, P'1 = 40kg/cm2 - the difference between P1 and P' 1 is always approximately 10kg/cm2 (even during slight brake application).