The figure reveals the vacuum clutch mechanism. This sort of clutch employs the existing vacuum while in the motor manifold to operate the clutch. The vacuum clutch contains a reservoir, non-return valve, vacuum cylinder with piston, and solenoid valve.  Go with a clutch package so you may have matching sections. https://clutchkereta97429.blog-ezine.com/33147901/5-simple-techniques-for-clutch-plate