Fuel Tank System, Checking For Leaks

Fuel Tank System, Checking for Leaks

• Always check for leaks after working on the fuel tank on the Audi R8 as follows:

• Before starting the work, make sure (VAS 6615) is working correctly.

Special tools, testers and auxiliary items required

• Tank leak tester Audi R8 (VAS 6615)

Making sure the (VAS 6615) is working correctly

• The (VAS 6615) is not connected to the vehicle.

- Connect (VAS 6615) to compressed air, 6 to 10 bar- 1 -.





- Open the shut-off valve - 2 -. The handle is horizontal.

- Read the display:

• Specified value: 180 mbar.

- Close the shut-off valve. The handle is vertical.

• Specified value: the pressure may drop maximum 5 to 10 mbar within 2 minutes.

• If the specified values were attained, then (VAS 6615) is OK and the testing can start.

• If the specified values were not attained, then (VAS 6615) is faulty and must be replaced.

CAUTION!
If the display on the (VAS 6615) exceeded 200 mbar during the functionality test or during the pressure test that followed, then the unit is faulty and must be disconnected immediately from the pressure supply.

Preparing for Leakage Test

- Remove the side panel cover - 1 - and fuel filler door insert.





- Remove the right engine compartment trim - 3 -.





- Remove the right engine control module from the bracket - arrows -.





- Loosen bolts - arrows - a few turns.





- Remove the bolt - 2 - and remove the right engine control module bracket - 1 -.

- Press the release buttons and remove the fuel tank bleed hose - arrow - from the EVAP canister - 1 -.





- Seal off the hose with a plug - 1 - taken from (VAS 6615).





- Remove the cover from the fuel filler tube.

- Install the adapter - 1 - from (VAS 6615) on the fuel filler tube.





- Connect the compressed air connecting line - 2 - from (VAS 6615) to the adapter from (VAS 6615).

Leakage Test

- Open the shut-off valve. The handle is horizontal.

• Compressed air flows into the fuel tank.

- Close the shut-off valve on (VAS 6615) after 5 minutes (the handle is vertical) and check the pressure inside the fuel tank.

- Read the display:

• Specified value: 180 mbar.

- Check the pressure in the fuel tank again after 2 minutes and read the display on the instrument.

• Specified value: the pressure may drop maximum 5 to 10 mbar within 2 minutes.

- If the specified value is not attained, find the leak in the fuel tank using a leak detection spray and repair. Repeat the leakage test.

- If the specified value is attained, (VAS 6615) disconnect the compressed air supply from the fuel tank.

Assembly is in reverse order of removal, note the following:

- Install the right engine compartment trim.

- Install the side panel cover and fuel filler door insert.