Fuel Tank: Testing and Inspection

Fuel Tank Ventilation, Checking

Special tools, testers and auxiliary items required
- Vacuum Tester V.A.G 1368
- Hand Vacuum Pump V.A.G 1390

Test sequence
- Remove front right wheelhousing liner.







- Disconnect ventilation line -2- from EVAP canister -1- at solenoid valve -3-.
- Connect connection "A" of Vacuum Tester V.A.G 1368 to EVAP canister using ventilation line -2-
- Connect Hand Vacuum Pump V.A.G 1390 to connection "B" of Vacuum Tester V.A.G 1368.
- Set Vacuum Tester V.A.G 1368 to position "A/B".
- Operate Hand Vacuum Pump V.A.G 1390 several times.
- No vacuum should be built up.

If vacuum is built up:
- Check breather hose -5- at EVAP canister -1- for soiling, clean if necessary.

If no vacuum is built up:
- Seal lines -5- and -6-.
- Operate Hand Vacuum Pump V.A.G 1390 several times.
- Vacuum must build up.

If no vacuum is built up:
- Replace EVAP canister -1- with pressure retaining valve -4-.

Check ventilation line
- Unscrew fuel filler cap from fuel filler tube.







- Connect Hand Vacuum Pump V.A.G 1390 to connection "B" of Vacuum Tester V.A.G 1368.
- Set Vacuum Tester V.A.G 1368 to position "A/B".
- Operate Hand Vacuum Pump V.A.G 1390 several times.
- No vacuum should be built up.

If vacuum is built up:
- Check gravity valve.
- Check line -1- from fuel tank for throughflow.

If no vacuum is built up:
- Screw fuel filler cap on fuel filler tube.
- Operate Hand Vacuum Pump V.A.G 1390 several times.
- No vacuum should be built up.

NOTE: At a low fuel level in fuel tank, Hand Vacuum Pump must be operated at least 20 to 30 times.

If vacuum is built up:
- Replace fuel filler cap for fuel filler tube.