Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Supply Line, Vacuum Reservoir And Check Valve, Checking
- Remove the engine cover. Refer to ENGINE COVER .
- Seal off the open ends of the hoses with plugs.
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.
- Watch the pressure gauge on the hand vacuum pump for approximately 30 seconds.
- The vacuum must 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 621-.
- Remove the plugs from the hose ends.
- If the check valve functions, a noticeable hissing can be heard as the vacuum in the vacuum reservoir 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 .
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.