Vacuum Advance Unit, Checking For Leakage

Vacuum advance unit, checking for leaks

Work sequence





- Connect vacuum tester VAG 1368 or equivalent according to manufacturer's instructions.
- Run engine at approx. 2500 RPM and check that vacuum at throttle valve housing is reaching vacuum unit.

If NO, vacuum connection on throttle valve housing may be blocked.

- Increase engine speed until vacuum tester indicates higher reading than 360 mbar (270mm Hg).
- Switch vacuum tester so it holds vacuum on side connected to vacuum unit.

- Turn engine OFF.
- Vacuum reading on tester must not drop more than 10% within 1 minute, otherwise vacuum unit or hose is defective.