Headlight levelling 1998 Boxer (1 Viewer)

[barrywi]

The headlights on my Boxer are levelled by turning a knob in the cab. This does not seem to do much so I was wondering if anyone knows how the system works? A clear plastic tubes comes from under the dash and links the two headlights together presumably to adjust the headlights in some way. Does anyone know if this is hydraulic or mechanical? I cannot see any electrical wires.

 

[joner8888]

It works on a vacum idea---
but hardly any of them still do work!