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Unscrew filler cap1 from filler neck.
Add engine oil as required.
Be careful not to overfill with oil.
Be careful not to spill any oil when adding.
Avoid environmental damage caused by oil
entering the ground or water.
Screw filler cap1 back on filler neck.
For more information on engine oil, see
“Technical data” (
page 443) and
Transmission fluid level*
Vehicles with automatic transmission*:
The transmission fluid level does not need
to be checked. If you notice transmission
fluid loss or gear shifting malfunctions,
have an authorized Mercedes-Benz Center
check the transmission.Coolant level
The engine coolant is a mixture of water
and anticorrosion/antifreeze. To check
the coolant level, the vehicle must be
parked on level ground and the engine
must be cool.
!Excess oil must be siphoned or drained off.
It could cause damage to the engine and
emission control system not covered by the
Mercedes-Benz Limited Warranty.Warning!G
In order to avoid any potentially serious
Use extreme caution when opening the
hood if there are any signs of steam or
coolant leaking from the cooling system,
or if the coolant temperature gauge indi-
cates that the coolant is overheated.
Do not remove pressure cap on coolant
reservoir if coolant temperature is
above 158°F (70°C). Allow engine to
cool down before removing cap. The
coolant reservoir contains hot fluid and
is under pressure.
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The coolant expansion tank is located on
the passenger side of the engine compart-
SLK 350 (example illustration)
1Coolant expansion tank
3Marking bar in the expansion tank
Using a rag, turn cap2 slowly approx-
imately one half turn counterclockwise
to release any excess pressure.
Continue turning cap2 counterclock-
wise and remove it.
The coolant level is correct if the level
for cold coolant: reaches marking
bar3 in expansion tank1
for warm coolant: is approximately
0.6 in (1.5 cm) higher
Add coolant as required.
Replace and tighten cap2.
For more information on coolant, see
Using a rag, slowly open the cap approx-
imately 1/2turn to relieve excess pres-
sure. If opened immediately, scalding
hot fluid and steam will be blown out un-
Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene
glycol which may burn if it comes into
contact with hot engine parts.
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Windshield washer system and
headlamp cleaning system*
The windshield washer reservoir is located
on the passenger side of the engine com-
SLK 350 (example illustration)
1Cap for windshield washer reservoir
Fluid for the windshield washer system
and the headlamp cleaning system* is
supplied from the windshield washer
reservoir. It has a capacity of
approximately 7.4 US qt (7 l).During all seasons, add MB Windshield
Washer Concentrate “MB SummerFit” to
water. Premix the windshield washer fluid
in a suitable container.
Use the tab to pull cap 1 upwards.
Refill the reservoir with MB Windshield
Washer Concentrate “MB SummerFit”
and water (or commercially available
premixed windshield washer
solvent/antifreeze, depending on
For more information, see “Windshield
washer system and headlamp cleaning
Washer solvent/antifreeze is highly flamma-
ble. Do not spill washer solvent/antifreeze
on hot engine parts, because it may ignite
and burn. You could be seriously burned.!Always use washer solvent/antifreeze
where temperatures may fall below freezing
point. Failure to do so could result in damage to
the washer system/reservoir.
!Only use washer fluid which is suitable for
plastic lenses. Improper washer fluid can dam-
age the plastic lenses of the headlamps.
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Your vehicle’s battery is located in the en-
The battery should always be sufficiently
charged in order to achieve its rated ser-
vice life. Refer to the Maintenance Booklet
for battery maintenance intervals.
If you use your vehicle mostly for
short-distance trips, you will need to
have the battery charge checked more
When replacing the battery, always use
batteries approved by Mercedes-Benz.
If you do not intend to operate your vehicle
for an extended period of time, consult an
authorized Mercedes-Benz Center about
steps you need to observe.Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
Observe all safety instructions and precau-
tions when handling automotive batteries.
Risk of explosion.
Fire, open flames and smoking
are prohibited when handling
batteries. Avoid creating sparks.
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
Wear suitable protective cloth-
ing, especially gloves, apron and
Wear eye protection.
Rinse any acid spills immediate-
ly with clear water. Contact a
physician if necessary.
Keep children away.
Follow the instructions in this
Page 305 from 473
Tires and wheels
Contact an authorized Mercedes-Benz
Center for information on tested and
recommended rims and tires for summer
and winter operation. They can also offer
advice concerning tire service and
Only use sets of tires and rims of the
same type and make.
Tires must be of the correct size for the
Break in new tires for approximately
60 miles (100 km) at moderate
Regularly check the tires and rims for
damage. Dented or bent rims can
cause tire inflation pressure loss or
damage the tire beads.
If vehicle is heavily loaded, check tire
inflation pressure and correct as
Do not allow your tires to wear down
too far. Adhesion properties on wet
roads are sharply reduced at tread
depths of less than
1/8in (3 mm).
When replacing individual tires, you
should mount new tires on the front
wheels first (on vehicles with
same-sized wheels all around).
Replace rims or tires with the same designa-
tion, manufacturer and type as shown on the
original part. Contact an authorized
Mercedes-Benz Center for further informa-
tion. If incorrectly sized rims and tires are
The wheel brakes or suspension compo-
nents can be damaged.
The operating clearance of the wheels
and the tires may no longer be correct.
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires have
sustained damage, replace them.
When replacing rims, only use genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can re-
sult in the bolts loosening and may lead to
Retreaded tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on
retreads. Mercedes-Benz therefore cannot
assure the operating safety of the vehicle
when such tires are used.