Audi 80 Quiz
Fuel tank and fuel pump

What is the purpose of fuel tank venting?

In this manual: Fuel tank and fuel pump
Technical Description — 39Engines — 41Exhaust System — 13Cooling System — 28Fuel tank and fuel pump — 12Air Filter and Intake Ducts — 13Mono-Motronic Injection System — 18Digifant Injection System — 19KE-III-Jetronic Injection System — 35MPI and MPFI Injection Systems — 32Clutch — 11Transmission and Driveline — 21Suspension and Steering — 33Brake System — 41Anti-lock brake system — 8Wheels and Tires — 13Body Electrical System — 35Ignition System — 24Lighting — 14Signaling Devices — 7Instruments and Auxiliary Equipment — 54Heating and Ventilation — 7Body Components — 18Troubleshooting — 6Specifications — 13
~1min read

Fuel tank venting is important for uninterrupted fuel supply: air must enter the tank in the same amount as fuel is consumed; otherwise, a vacuum forms in the fuel tank and fuel delivery stops.

The fuel tank must be vented to allow its contents to expand when heated.

During refueling, air must be able to escape from the tank, because otherwise the fuel being added will rise back up to the filler neck and begin to overflow.

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A quick Audi 80 quiz: every answer comes with an explanation and a link to the manual page.