Checking the pneumatic headlight beam tilt regulator (Mercedes-Benz S-Class W140)

1. The pneumatic regulator is not installed on vehicles with clearance adjustment depending on the vehicle load. The headlight beam angle can be adjusted by the switch (1).



2. The pneumatic lines (2) are connected to the switch (1) by quick-release connectors or, as of 10.93, by shrink fitting. The shut-off valve integrated into the switch (1) closes the vacuum tubes according to the position of the regulator. The switch (1) is supplied with vacuum from the inlet pipe via the vacuum distribution block.



3. The switch (1) has several positions: "0", "1", "2" and "3". Different positions of the regulator apply different vacuum depths to hold the reflector in the desired position.

Dependence of the vacuum depth on the regulator position

Regulator position	Adjustment position of the installation element, mm	Vacuum depth, bar
0	0.0	400±30
1	0.95	290±30
2	1.70	200±30
3	3.00	50±30

Article text obtained from the website [MERCEDESMAN]