2004 MERCEDES-BENZ G55AMG Owner's Manual

233 Operation
Engine compartment
The coolant expansion tank is located on
the passenger side of the engine compart-
ment.
1Cap

Using a rag, turn the cap slowly approx-
imately one half turn to the left to re-
lease any excess pressure.

Continue turning the cap to the left and
remove it.

Check coolant level.
The coolant level is correct if the level

for cold coolant: is level with the
mark on the reservoir


for warm coolant: is approx. 0.6 in
(1.5 cm) higher

Add coolant as required.

Replace and tighten cap until you hear
it click a few times.
For more information on coolant, see
“Coolants” (
page 336).
Warning!
G
In order to avoid any possibly serious burns:

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 display in-
dicates that the coolant is overheated.


Do not remove pressure cap on coolant
reservoir if engine temperature is above
194°F (90°C). Allow engine to cool
down before removing cap. The coolant
reservoir contains hot fluid and is under
pressure.


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-
der pressure.


Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene gly-
col which may burn if it comes into con-
tact with hot engine parts.

234 OperationEngine compartmentWindshield/rear window washer sys-tem and headlamp cleaning system
The windshield washer reservoir is located
in the engine compartment on the passen-
ger side. It holds approximately 5.3 US qt
(5.0 l). The headlamp cleaning system is
also supplied from the windshield washer
reservoir.
1Cap

Use the tab to pull cap1 upwards.

Check washer solvent level and add
washer solvent as required.

Press cap1 on the filler neck until is
has completely engaged.
Add MB Windshield Washer Concentrate
“S” to the water during all seasons.


At temperatures above freezing point,
use MB Windshield Washer Concen-
trate “S” to prevent smearing.


If there is a danger of frost, use
MB Windshield Washer Concentrate
“S” and commercially available pre-
mixed windshield washer solvent/anti-
freeze to prevent water from freezing
on the windshield and the reservoir
from being damaged.
Premix the windshield washer fluid in a
suitable container, adapting the mixing ra-
tio to the outside temperature
(
page 339).
Warning!
G
Washer solvent / antifreeze is highly flam-
mable. Do not spill washer
solvent /antifreeze on hot engine parts, be-
cause it may ignite and burn. You could be
seriously burned.!Only use washer fluid which is suitable
for plastic lenses. Improper washer flu-
id can damage the plastic lenses of the
headlamps.

235 Operation
Battery
Battery
The battery is located in front of the rear
seat bench and below the cup holder. Jump
starting terminals are located in the left
side of the engine compartment
(page 314). Refer to Service Booklet for
battery maintenance intervals.
The battery should always be sufficiently
charged in order to achieve its rated ser-
vice life.
If you use your vehicle less than approxi-
mately 200 miles (300 km) per month,
mostly for short-distance trips, or if it is not
used for long periods of time, you will need
to have the battery charge checked more
frequently and corrected if necessary.
When replacing batteries, always use bat-
teries approved by Mercedes-Benz.
If you do not intend to operate your vehicle
for an extended period of time, consult an
authorized Mercedes-Benz Light Truck
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
for recycling.
For more information, see “Battery”
(
page 311).
G
Observe all safety instructions
and precautions when handling
automotive batteries.
A
Risk of explosion
D
Keep flames or sparks away
from battery. Do not smoke.
B
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
In case it does, immediately
flush affected area with clear
water and seek medical help if
necessary.
E
Wear eye protection.
C
Keep children away.
F
Follow the instructions in this
Operator’s Manual.
iIf the battery is discharged

you will no longer be able to turn
the SmartKey in the starter switch


the gear selector lever will remain
locked in positionP

236 OperationTires and wheels
Tires and wheelsSee your authorized Mercedes-Benz Light
Truck Center for information on tested and
recommended rims and tires for summer
and winter operation. They can also offer
advice concerning tire service and pur-
chase.
Retreaded tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on
retreads. Mercedes-Benz can therefore
not assure the operating safety of the vehi-
cle when such tires are used.
Important guidelines

Use only sets of tires and rims of the
same type and make.


Tires must be of the correct size for the
rim.


Break in new tires for approximately
60 miles (100 km) at moderate
speeds.


Regularly check the tires and rims for
damage. Dented or bent rims can
cause tire pressure loss and damage to
the tire beads.


If vehicle is heavily loaded, check tire
pressure and correct as required.


Do not allow your tires to wear down
too far. Adhesion properties on wet
roads are sharply reduced at tread
depths under
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).
Warning!
G
Replace rims or tires with the same designa-
tion, manufacturer and type as shown on the
original part. See your authorized
Mercedes-Benz Light Truck Center for fur-
ther information. If incorrectly sized rims
and tires are mounted:

The wheel brakes or suspension compo-
nents can be damaged.


The correct operating clearance of the
wheels and the tires are no longer guar-
anteed.
Warning!
G
Do not mix different tire construction types
(i.e. radial, bias, bias-belted) on your vehicle
because handling may be adversely affected
and may result in loss of control.Warning!
G
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, use only genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can re-
sult in the bolts loosening and possibly an
accident.

237 Operation
Tires and wheels
Life of tire
The service life of a tire is dependent upon
varying factors including but not limited to:

Driving style


Tire pressure


Distance driven
Direction of rotation
Unidirectional tires offer added advantag-
es, such as better hydroplaning perfor-
mance. To benefit, however, you must
ensure the tires rotate in the direction
specified.
An arrow on the sidewall indicates the in-
tended direction of rotation of the tire.
Checking tire inflation pressure
Correct the tire pressure only when tires
are cold.
Regularly check your tire pressure at inter-
vals of no more than 14 days.
If the tires are warm, you should only cor-
rect the tire pressure if it is too low for cur-
rent operating conditions.
A table on the fuel filler flap lists the spec-
ified tire inflation pressures for warm and
cold tires as well as for various operating
conditions.
Warning!
G
Tires and spare wheel should be replaced af-
ter six years, regardless of the remaining
tread.!Keep unmounted tires in a cool, dry
place with as little exposure to light as
possible. Protect tires from contact
with oil, grease and gasoline.
Warning!
G
If the tire pressure drops repeatedly:

Check the tires for punctures from for-
eign objects.


Check to see whether air is leaking from
the valves or from around the rim.

238 OperationTires and wheelsTire pressure changes by approximately
1.5 psi (0.1 bar) per 18°F (10°C) of air
temperature change. Keep this in mind
when checking tire pressure where the
temperature is different from the outside
temperature.
Tire temperature and tire pressure are also
increased while driving, depending on the
driving speed and the tire load.Check the spare tire periodically for condi-
tion and inflation. Spare tire will age and
b e c o m e w o r n o v e r t i m e e v e n i f n e v e r u s e d ,
and thus should be inspected and replaced
when necessary.
Rotating wheels
The wheels can be rotated every 3000 to
6 000 miles (5 000 to 10 000 km) or soon-
er if necessary, according to the degree of
tire wear. The same direction of tire rota-
tion must be retained.
Rotate the wheels before the characteris-
tic tire wear pattern becomes visible
(shoulder wear on front wheels and tread
center wear on rear wheels).
Thoroughly clean the inner side of the
wheels after each rotation. Check and en-
sure proper tire inflation pressure.
iThe pressures listed for light loads are
minimum values offering high driving
comfort.
Increased inflation pressures listed for
heavier loads may also be used for light
loads. These higher pressures produce
favorable handling characteristics. The
ride of the vehicle, however, will be
somewhat harder. Never exceed the
max. values or inflate tires below the
min. values listed in the fuel filler flap.
Warning!
G
Follow recommended inflation pressures.
Do not overinflate tires. Overinflated tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes,
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.
Do not overload the tires by exceeding the
Gross Vehicle Weight Rating (GVWR) and
the Gross Axle Weight Rating (GAWR) as in-
dicated on the certification label on the driv-
er’s door pillar. Overloading the tires can
overheat them, possibly causing a blowout.
Warning!
G
Rotate front and rear wheels only if there are
of the same size.

239 Operation
Tires and wheels
Warning!
G
Have the tightening torque checked after
changing a wheel. Wheels could become
loose if not tightened with a torque of
97 lb-ft (130 Nm).
Use only genuine Mercedes-Benz wheel
bolts specified for your vehicle’s rims.

240 OperationWinter driving
Winter drivingBefore the onset of winter, have your vehi-
cle winterized at an authorized
Mercedes-Benz Light Truck Center. This
service includes:

Check of anticorrosion and antifreeze
concentration.


Addition of cleaning concentrate to the
water of the windshield and headlamp
cleaning system. Add MB Concentrate
“S” to a premixed windshield washer
solvent/antifreeze which is formulated
for below freezing point temperatures
(page 339).


Battery test. Battery capacity drops
with decreasing ambient temperature.
A well charged battery helps to ensure
the engine can be started even at low
ambient temperatures.


Tire change. Mercedes-Benz recom-
mend M+S rated radial-ply tires with a
minimum tread depth of approximately 1⁄6in (4 mm) on all four wheels for the
winter season.
Winter tires
Always use winter tires at temperatures
below 45°F (7°C) and whenever wintry
road conditions prevail. Use of winter tires
is the only way to achieve the maximum ef-
fectiveness of the ABS, ESP, EBB and
4-ETS in winter operation.
For safe handling, make sure all winter
tires mounted are of the same make and
have the same tread design.
Always observe the speed rating of the
winter tires installed on your vehicle. If the
maximum speed for which your tires are
rated is below the speed rating of your ve-
hicle, you must place a notice to this effect
where it will be seen by the driver. Such no-tices are available at your tire dealer or any
authorized Mercedes-Benz Light Truck
Center.
Block heater (Canada only)
The engine is equipped with a block heat-
er.
The electrical cable may be installed at
your authorized Mercedes-Benz Center.
Warning!
G
Winter tires with a tread depth under
1⁄6in
(4 mm) must be replaced. They are no long-
er suitable for winter operation.
Warning!
G
If you use your spare tire when winter tires
are fitted on the other wheels, be aware that
the difference in tire characteristics may
very well impair turning stability and that
overall driving stability may be reduced.
Adapt your driving style accordingly.
Have the spare tire replaced with a winter
tire at the nearest authorized
Mercedes-Benz Light Truck Center.