Hose Setup, Checking
- Disconnect vacuum line at intake manifold.
Scheme 833
- 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).