Checking Vacuum Control Unit of Bypass Flaps

1. Detach cover frame from charge air cooler.
2. Remove hose between frequency valve and throttle body from throttle body.

Special Tool 9160/1:

3. Connect special tool 9160/1 to removed hose.

Frequency Valve:

4. Use commercially available hose clamp to pinch hose between frequency valve and front intake pipe.

Measuring Push Rod Travel:

5. Fit dial gauge and dial gauge holder VW 387 to heat shield of turbocharger (using G clamp). Place measuring pin on fastening bracket.

- Use special tool 9160/1 to create excess pressure of approx. 0.5 bar.
- The push rod must be lifted by 4 + 0.5 mm;
- If required, readjust by turning adjustment nuts.

- Turning clockwise - lift decreases.
- Turning counterclockwise - lift increases.