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Vacuum System, Checking For Leaks






Diagnostic Procedures

Vacuum System, Checking for Leaks

Hose Setup, Checking

- Disconnect vacuum line at intake manifold.

- Connect hand vacuum pump (VAG1390) to disconnected vacuum line.





- Operate hand vacuum pump at least 50 times (Vacuum build-up must be noticeable when operating).

- Disconnect hose from hand vacuum pump.

During this, vacuum must be released only between hand vacuum pump and check-valve.

- If further vacuum is audibly released, check-valve is leaky (replace check-valve).

Vacuum Diaphragm, Checking

- Disconnect vacuum line from vacuum diaphragm for intake manifold change-over.

- Connect hand vacuum pump directly to vacuum diaphragm.

- Operate hand vacuum pump and observe change-over procedure during this.

- Check vacuum reservoir for proper seal.

Specified value: Vacuum diaphragm must not return to output position, as long as the hand vacuum pump is not vented.

If vacuum diaphragm moves back.

- Replace vacuum diaphragm.
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