Volkswagen Workshop Service and Repair Manuals

Special tools, workshop equipment, testers, measuring instruments and auxiliary items required

• ◆ V.A.G 1368 Vacuum tester

• ◆ V.A.G 1390 Hand vacuum pump

Test conditions

• ● Ignition must be switched off

Test sequence

• ‒ → Pull vent hose -1- from activated charcoal filter off solenoid valve -2-.
• ‒ Connect hand vacuum pump V.A.G 1390 and vacuum tester V.A.G 1368 as shown to hose -1-.
• ‒ Set vacuum tester to -A/B- position.
• ‒ Operate hand vacuum pump V.A.G 1390 several times.
       Vacuum must not
  build up.

If vacuum builds up:

• ‒ Check breather connection -3- located on bottom of activated charcoal filter -4- for soiling, clean if necessary.

If vacuum does not build up:

• ‒ Temporarily seal breather connection -3- and operate vacuum pump again several times.
       A vacuum must build up.
  (Vacuum non-return valve in activated charcoal filter must close).

If vacuum does not build up:

• ‒ Renew activated charcoal filter.

Checking lines to fuel tank and fuel cap

• ‒ → Pull vent hose -1- from fuel tank off activated charcoal filter -2-.
• ‒ Connect hand vacuum pump V.A.G 1390 and vacuum tester V.A.G 1368 as shown to hose -1-.
• ‒ Set vacuum tester to -A/B- position.
• ‒ Remove fuel filler cap from filler neck.
• ‒ Operate V.A.G 1390 several times. Vacuum must
       not build-up.

If vacuum builds-up:

• ‒ Check gravity/overflow valve , item 4
• ‒ Check line -1- from fuel tank for blockage.

If vacuum does not build up:

• ‒ Refit fuel filler cap.
• ‒ Operate hand vacuum pump V.A.G 1390 several times.
       Vacuum must not
  build up.

Note:

If the fuel level in the tank is low the hand vacuum must be operated at least 20...30 times.

If vacuum builds up:

• ‒ Replace fuel tank cap.