How Does The Fuel Pump Know When To Shut Off?

Have you ever wondered how the fuel pump nozzle knows when to shut off when you are pumping fuel?  Well, here is a simple video that explains the inner workings of a fuel nozzle, and how it 'knows' when to shut off...

The explanation involves air, fluid, flow, pressure and the Venturi effect.  Happy motoring!

(Via Youtube)