Vacuum System, Checking

Vacuum System, Checking

=> [ Supply Line and Check Valve, Checking ]

=> [ Control Line to Turbocharger, Checking ]

Special tools, testers and auxiliary items required

• Hand Vacuum Pump (VAS 6213)


• When routing the vacuum lines, make sure they are not kinked, twisted or pinched. They could disable the vehicle.

• Follow the safety precautions when working on the charge air system and turbocharger. Refer to => [ Safety Precautions ] Safety Precautions.

• Observe the rules for cleanliness. Refer to => [ Clean Working Conditions ] Clean Working Conditions.

Always follow these instructions before and during work.

Supply Line and Check Valve, Checking

- Remove the engine cover. Refer to => [ Engine Cover ] Engine Cover.

Disconnect the vacuum hose from the lower connection on the wastegate bypass regulator valve (N75) - arrow in I -.

- Sealing the open end of the hose with a suitable plug.

• Do not use threaded bolts or pins.

- Disconnect the vacuum hose - arrow - at the vacuum pump connecting piece.






- Connect the hand vacuum pump (VAS 6213) to the removed hose and generate a vacuum of 0.6 bar.

- Observe the pressure gauge on the hand vacuum pump (VAS 6213) for approximately 30 seconds.

• The vacuum may not drop.

If the vacuum drops:

- Replace the hose piece if there is damage or leaks in the hose line connection.

If the vacuum does not decrease:

- First disconnect the hose at the hand vacuum pump (VAS 6213).

- Remove the plugs from the end of the hose.

- If the check valve - item 6 - in => [ Vacuum Hose Connection Diagram ] [1][2]Diagrams functions, a noticeable hissing can be heard as the vacuum reduces.

If there is not a hissing sound:

- Replace the check valve.

If there is a hissing sound:

- Connect all the vacuum hoses.

- Check the control line to the turbocharger. Refer to => [ Control Line to Turbocharger, Checking ].

Control Line to Turbocharger, Checking

- Disconnect the vacuum hose at the center connection on the wastegate bypass regulator valve (N75) - item 2 - in => [ Vacuum Hose Connection Diagram ] [1][2]Diagrams and the turbocharger vacuum diaphragm - item 1 - in => [ Vacuum Hose Connection Diagram ] [1][2]Diagrams.

- Seal the opening in the hose with suitable plugs.

• Do not use threaded bolts or pins.

- Connect the hand vacuum pump (VAS 6213) to the other end of the hose and generate a vacuum of 0.6 bar.

- Observe the pressure gauge on the hand vacuum pump (VAS 6213) for approximately 30 seconds.

• The vacuum may not drop.

If the vacuum drops:

- Replace the vacuum hose.

- Connect all the vacuum hoses.

- Install the engine cover. Refer to => [ Engine Cover ] Engine Cover.

If the vacuum does not decrease:

- Connect all the vacuum hoses.

- Install the engine cover. Refer to => [ Engine Cover ] Engine Cover.