The determine demonstrates the vacuum clutch system. This sort of clutch works by using the prevailing vacuum during the motor manifold to work the clutch. The vacuum clutch contains a reservoir, non-return valve, vacuum cylinder with piston, and solenoid valve.  An automobile air conditioning compressor that has a magnetic clutch. https://zandertvsro.ttblogs.com/12660998/details-fiction-and-clutch-kereta