Checking fuel tank and fuel filler cap

WARNING: This page does not describe the selected car, but rather 25 other vehicles, including the 2002 Volkswagen Cabrio, 2001 Volkswagen Cabrio, 2000 Volkswagen Cabrio, 1999 Volkswagen Jetta, and 1999 Volkswagen Golf. However, it is still accessible from the selected car via links, so may be relevant.

Remove fuel filler cap.
Connect VAG 1390 to breather hose -3- from fuel tank (previously removed from EVAP canister -4-).

Fig 1: Checking Fuel Tank & Fuel Filler Cap (Vehicles Up To 1996)
Courtesy of VOLKSWAGEN OF AMERICA, INC.
Operate VAG 1390 hand vacuum pump several times.
- Vacuum must not build up

If vacuum builds up:

Check gravity valve, see Figure , item -33-.
Check line -3- (from fuel tank) for blockage.

If vacuum does not build up:

Reinstall fuel filler cap.
Operate VAG 1390 hand vacuum pump several times.
- Vacuum must not build up

NOTE: If the fuel levels are low, it will take much longer to build vacuum, so the pump must be operated at least 20 to 30 times.

If vacuum builds up:

Replace fuel filler cap.