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188Vehicle careThe filter is drained as soon as dieselfuel emerges from the knurled screw
at the bottom. Retighten the two
screws.
Check diesel fuel filter at shorter
intervals if the vehicle is subjected to
extreme operating conditions.
Diesel fuel system bleeding
If the fuel tank has been run dry, it will be necessary to air vent or bleed the
diesel fuel system.
Fill the tank with fuel and proceed as
follows:
1. Place a suitable container underneath the fuel filter vent
screw to collect fuel.
2. Loosen the vent screw (arrowed) by one turn.
3. Manually operate the in-line supply pump slowly and steadily
until fuel discharging from the
loosened vent screw is free of air
bubbles.
4. Retighten the vent screw.
In vehicles without an in-line supply
pump, fill the tank with fuel and
proceed as follows:Caution
Do not turn ignition key to position 3 before beginning the bleeding
procedure.
Ignition switch positions 3 136.
1. Turn ignition key to position 2 and
hold for 5 seconds.
2. Turn key back to position 1 and
wait for 3 seconds.
3. Repeat Step 1 and 2 multiple times.
4. Turn key to position 3, then return
to 0.
If the engine cannot be started after
several attempts to bleed the diesel
fuel system, seek the assistance of a
workshop.
Wiper blade replacement
Wiper blades on the windscreen If required, use the step located below
the headlights to reach the
windscreen wiper.
Page 224 of 269

222Vehicle careDo not clean the engine compartmentwith a steam-jet or high-pressure jet
cleaner.
Thoroughly rinse and leather-off the
vehicle. Rinse leather frequently. Use
separate leathers for painted and
glass surfaces: remnants of wax on
the windows will impair vision.
Exterior lights
Headlight and other light covers are
made of plastic. Do not use any
abrasive or caustic agents, do not use
an ice scraper, and do not clean them
dry.
Polishing and waxing
Wax the vehicle regularly (at the
latest when water no longer beads).
Otherwise, the paintwork will dry out.
Polishing is necessary only if the paint
has become dull or if solid deposits
have become attached to it.
Paintwork polish with silicone forms a
protective film, making waxing
unnecessary.Unpainted plastic body parts must not be treated with wax or polishing
agents.
Matt filmed body parts or decor tapes must not be polished, to avoid
gleaming. Do not use hot wax
programmes in automatic car washes
if the vehicle is equipped with these
parts.
Matt painted decor parts, e.g. mirror
housing cover, must not be polished.
Otherwise these parts would become agleam or the colour would be
dissolved.
Windows and windscreen wiper
blades
Use a soft lint-free cloth or chamois
leather together with window cleaner
and insect remover.
When cleaning the rear window from
inside, always wipe in parallel to the
heating element to prevent damage.
For mechanical removal of ice, use a
sharp-edged ice scraper. Press the
scraper firmly against the glass so
that no dirt can get under it and
scratch the glass.Remove dirt residues from smearing
wiper blades by using a soft cloth and window cleaner. Also make sure to
remove any residues such as wax,
insect residues and similar from the
window.
Wheels and tyres Do not use high-pressure jet
cleaners.
Clean rims with a pH-neutral wheel
cleaner.
Rims are painted and can be treated
with the same agents as the body.
Paintwork damage
Rectify minor paintwork damage with
a touch-up pen before rust forms.
Have more extensive damage or rust areas repaired by a workshop.
Underbody
Some areas of the vehicle underbody
have a PVC undercoating while other critical areas have a durable
protective wax coating.
Page 228 of 269

226Service and maintenanceEngine oil viscosity grades
The SAE viscosity grade gives
information of the thickness of the oil.
Multigrade oil is indicated by two
figures, e.g. SAE 5W-30. The first
figure, followed by a W, indicates the
low temperature viscosity and the
second figure the high temperature viscosity.
Select the appropriate viscosity grade
depending on the minimum ambient
temperature 3 229.
All of the recommended viscosity
grades are suitable for high ambient
temperatures.
Coolant and antifreeze
Use only silicate-free long life coolant (LLC) antifreeze approved for the
vehicle. Consult a workshop.
The system is factory filled with
coolant designed for excellent
corrosion protection and frost
protection down to approx. -28 °C.
This concentration should be
maintained all year round. The use of additional coolant additives that
intend to give additional corrosionprotection or seal against minor leaks
can cause function problems. Liability
for consequences resulting from the
use of additional coolant additives will be rejected.
Washer fluid Use only washer fluid approved for
the vehicle to prevent damage of
wiper blades, paintwork, plastic and
rubber parts. Consult a workshop.
Brake fluid Over time, brake fluid absorbs
moisture which will reduce braking
effectiveness. The brake fluid should
therefore be replaced at the specified
interval.
AdBlue Only use AdBlue to reduce the
nitrogen oxides in the exhaust
emission 3 145.