Mercedes-Benz R 350 BlueTEC 2012 Operator's Manual page 164

Refueling
162
use a sponge and cold water to clean it. DEF
residues crystallize after time and
contaminate the affected surfaces.
! DEF is not a fuel additive and must not be
added to the fuel tank. If DEF is added to
the fuel tank, this can lead to engine
damage.
i If you are adding between maintenance
intervals, add approximately 1 gallon (3.8 l)
of DEF to the DEF tank. One gallon (3.8 l)
of DEF is approximately 2 DEF refill bottles.
For further information on DEF, see:
( Y page 357).
The DEF filler neck is under the cargo
compartment floor.
X
Switch off the ignition.
X
Open the tailgate.
X
Lift up the trunk floor (
X
Remove lug wrench ; and ratchet wrench
= if applicable.
X
Turn DEF cap : counter-clockwise and
remove it.
Y
page 296).
I n f o r ma t i o n P r o v i d e d b y :
X
Turn DEF filler cap ? counter-clockwise
and open it.
Filler cap ? is secured with a plastic strap.
X
Unscrew the covering cap from DEF refill
bottle A.
X
Place DEF refill bottle A on the filler neck
as shown and screw on clockwise hand-
tight.
! Only screw on the DEF refill bottle hand-
tight. It could otherwise be damaged.
X
Press DEF refill bottle A down.
The DEF tank is filled. This may take up to
one minute.
i If the DEF refill bottle is no longer pressed
down, the filling process stops and the
partially emptied bottle can be removed.
X
Release DEF refill bottle A.
X
Turn DEF refill bottle A counter-clockwise
and remove it.
X
Place DEF filler cap ? on the filler neck and
turn it clockwise.