Draining The Fuel Prefilter - Mercedes-Benz Unimog Operating Instructions Manual

Avoid fire, naked flames, smoking and creat-
ing sparks under all circumstances. Switch off
the ignition and auxiliary heating before car-
rying out work to the fuel system. Always wear
protective gloves.
H
Environmental note
Dispose of the water-fuel mixture in an envi-
ronmentally responsible manner.
H
Environmental note
Dispose of used filter elements, seals and fuel
residue in accordance with relevant local reg-
ulations.

Draining the fuel prefilter

Drain fuel prefilter : regularly.
X
Remove bolts ; on cover plate =.
X
Remove cover plate =.
Example
Hand pump
?
Shutoff valve
A
Inspection window
B
Drain plug
C
X
Place a collector under drain plug C.
X
Open drain plug C. To do so, turn the drain
plug to the left.
X
Press hand pump ? several times in suc-
cession and collect the fuel/water mixture.
X
Close drain plug C. To do so, screw the
drain plug tightly to the right.
X
Bleed the fuel system (
X
Check the fuel system for leaks.
Replacing the fuel prefilter
Example
Filter head
:
Hand pump
;
Bleed screw
=
Shutoff valve
?
Filter element
A
Sealing ring
B
Sealing ring
C
Water separator
D
Drain plug
E
X
Place a collector under drain plug E.
X
Open drain plug E and bleed screw =.
Collect the draining water-fuel mixture.
Engine
Y page 322).
Z
321