The figure demonstrates the vacuum clutch system. This type of clutch uses the prevailing vacuum inside the motor manifold to function the clutch. The vacuum clutch is made up of a reservoir, non-return valve, vacuum cylinder with piston, and solenoid valve.  The springs preserve the flywheel transferring ahead or backward https://beckettvvsqo.activosblog.com/32084394/clutch-plate-an-overview