mm. HG or PSI? All my gauges are psi or Kg/cm2. I think your pressures given are really psi.

1 mm Hg is ~ .01933 psi.

Typical cutout pressures are 2 bar low; 30 bar high. (~30 psi ; 450 psi)

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1RX11DXS31S01A6ZA0&year=1986&make=MB&model=420-SEL-001&category=R&part=A%2FC+Pressure+Switch

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)