2008 MERCEDES-BENZ R320 maintenance

504 Practical hints
Battery
!The battery is a valve-regulated lead acid
(VRLA) battery, also referred to as “fleece”
battery. Such batteries do not require topping-up
of the electrolyte level. VRLA batteries therefore
do not have cell caps and the battery cover is
non-removable. Do not attempt to open the
battery as otherwise the battery will be dam-
aged.
Even though VRLA batteries do not require
topping-up of the electrolyte level and cannot be
opened to check the electrolyte level, the
battery condition must be checked periodically
by performing a battery conductance test. Refer
to Maintenance Booklet for battery condition
testing intervals.
As with any other battery, the battery may
discharge if the vehicle is not operated for an
extended period of time. You can connect a
battery maintenance charge unit tested and
approved for use on your vehicle model or dis-
connected the battery to prevent battery dis-
charge. Contact an authorized Mercedes-Benz
Light Truck Center for more information.!The factory-equipped VRLA battery is
leak-proofed. Only use a battery as replacement
that has the same security features and is of
identical size, voltage, and capacity as the
factory-equipped battery.
The battery, the battery ventilation and the later-
al plug must always be securely installed when
the vehicle is in operation.
Warning!G
Jump starting must only be done using the
jump-start contacts located in the engine
compartment (
page 511).
Warning!G
Failure to follow these instructions can re-
sult in severe injury or death.
Observe all safety instructions and precau-
tions when handling automotive batteries
(
page 503).
Never lean over batteries while connecting,
you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking etc.

529 Technical data
Rims and tires
Rims and tires
!Only use tires which have been tested and
approved by Mercedes-Benz. Tires approved by
Mercedes-Benz are developed to provide best
possible performance in conjunction with the
driving safety systems on your vehicle such as
ABS or ESP
®. Tires specially developed for your
vehicle and tested and approved by
Mercedes-Benz can be identified by finding the
following on the tire’s sidewall:

MO = Mercedes-Benz Original equipment
tires
Using tires other than those approved by
Mercedes-Benz may result in damage that is
not covered by the Mercedes-Benz Limited
Warranty.
!Using tires other than those approved by
Mercedes-Benz can have detrimental effects,
such as

poor handling characteristics

increased noise

increased fuel consumption
Moreover, tires and rims not approved by
Mercedes-Benz may, under load, exhibit dimen-
sional variations and different tire deformation
characteristics that could cause them to come
into contact with the vehicle body or axle parts.
Damage to the tires or the vehicle may be the
result.
iFurther information on tires and rims is
available at any authorized Mercedes-Benz Light
Truck Center. A placard with the recommended
tire inflation pressures is located on the driver’s
door B-pillar (
page 366). Some vehicles may
have supplemental tire inflation pressure infor-
mation for driving at high speeds (
page 372)
or for vehicle loads less than the maximum
loaded vehicle condition (
page 372). If such
information is provided, it can be found on the
placard located on the inside of the fuel filler
flap.The tire inflation pressure should be checked
regularly and should only be adjusted on cold
tires. Follow tire manufacturer’s maintenance
recommendation included with vehicle.
iThe following pages also list the approved
wheel rim and tire sizes for equipping your vehi-
cles with winter tires. Winter tires are not avail-
able as standard or optional factory equipment,
but can be purchased from an authorized
Mercedes-Benz Light Truck Center.
Depending on vehicle model and the standard or
optional factory-equipped wheel rim/tire
configuration on your vehicle (Appearance
Package, Sport Package etc.), equipping your
vehicle with winter tires approved for your
vehicle model may also require the purchase of
two or four wheel rims of the recommended size
for use with these winter tires. Contact an
authorized Mercedes-Benz Light Truck Center
for more information.

538 Technical data
Fuels, coolants, lubricants, etc.
Engine oils
Engine oils are specifically tested for their
suitability in our engines and durability for
our service intervals. Therefore, only use
approved engine oils and oil filters
required for vehicles with Maintenance
System. For a listing of approved engine
oils and oil filters, refer to the Factory
Approved Service Products pamphlet (USA
only), or contact an authorized
Mercedes-Benz Light Truck Center.Engine oil additives
Air conditioning refrigerant
R-134a (HFC) refrigerant and special PAG
lubricating oil are used in the air condition-
ing system.
ModelCapacityFuels, coolants, lubricants, etc.
Air conditioning systemR-134a refrigerant and special PAG lubricant
oil (never R-12)
Windshield washer
system and headlamp
cleaning system*8.0 US qt (7.6 l)MB Windshield Washer Concentrate1
1Use MB Windshield Washer Concentrate “MB SummerFit” and water for temperatures above freezing point or MB Windshield Washer Concentrate “MB SummerFit”
and commercially available premixed windshield washer solvent/antifreeze for temperatures below freezing point. Follow suggested mixing ratios (page 544).
!Using engine oils and oil filters of
specification other than those expressly
required for the Maintenance System, or chang-
ing of oil and oil filter at change intervals longer
than those called for by the Maintenance System
will result in engine or emission control system
damage not covered by the Mercedes-Benz
Limited Warranty.
Please follow Maintenance System recommen-
dations for scheduled oil changes. Failure to do
so will result in engine or emission control
system damage not covered by the
Mercedes-Benz Limited Warranty.
!Do not blend oil additives with engine oil.
They may damage the engine.
Damage or malfunctions resulting from blending
oil additives are not covered by the
Mercedes-Benz Limited Warranty.
!Never use R-12 (CFC) or mineral-based
lubricating oil. Otherwise damage to the system
will occur.

539 Technical data
Fuels, coolants, lubricants, etc.
Brake fluid
Only brake fluid approved by
Mercedes-Benz is recommended. Your
authorized Mercedes-Benz Light Truck
Center will provide you with additional
information.Premium unleaded gasoline
(gasoline engine)
Warning!G
During vehicle operation, the boiling point of
the brake fluid is continuously reduced
through the absorption of moisture from the
atmosphere. Under extremely strenuous
operating conditions, this moisture content
can lead to the formation of bubbles in the
system, thus reducing the system’s
efficiency.
Therefore, the brake fluid must be
replaced regularly. Refer to your vehicle’s
Maintenance Booklet for replacement
interval.
Warning!G
Gasoline is highly flammable and poisonous.
It burns violently and can cause serious
personal injury.
Never allow sparks, flame or smoking mate-
rials near gasoline!
Turn off the engine before refueling.
Whenever you are around gasoline, avoid in-
haling fumes and skin or clothing contact,
extinguish all smoking materials.
Direct skin contact with gasoline and the in-
halation of gasoline vapors are damaging to
your health.
!To maintain the engine’s durability and
performance, premium unleaded gasoline must
be used. If premium unleaded gasoline is not
available and low octane fuel is used, follow
these precautions:

Have the fuel tank only partially filled with
unleaded regular gasoline and fill up with
premium unleaded gasoline as soon as
possible.

Avoid full throttle driving and abrupt acceler-
ation.

Do not exceed an engine speed of 3 000 rpm
if the vehicle is loaded with a light load such
as two persons and no luggage.

Do not exceed2/3of maximum accelerator
pedal position if the vehicle is fully loaded or
operating in mountainous terrain.

541 Technical data
Fuels, coolants, lubricants, etc.
In areas where carbon deposits may be
encountered due to lack of availability of
gasolines which contain these additives,
Mercedes-Benz recommends the use of
additives approved by us for use on
Mercedes-Benz vehicles. Refer to Factory
Approved Service Products pamphlet (USA
only) or contact an authorized
Mercedes-Benz Light Truck Center for a
listing of approved product(s). Follow
directions on product label.
Do not blend other specific fuel additives
with fuel. This only results in unnecessary
costs and may be harmful to the engine
operation.Coolants
The engine coolant is a mixture of water
and anticorrosion/antifreeze, which
provides:

Corrosion protection

Freeze protection

Boiling protection (by increasing the
boiling point)
The cooling system was filled at the factory
with a coolant providing freeze protection
to approximately -35°F (-37°C) and
corrosion protection.If the antifreeze mixture is effective to
-35°F (-37°C), the boiling point of the cool-
ant in the pressurized cooling system is
reached at approximately 266°F (130°C).
The coolant solution must be used year
round to provide the necessary corrosion
protection and increase boil-over protec-
tion. Refer to Maintenance Booklet for
replacement interval.
!Damage or malfunction resulting from poor
fuel quality or from blending additional fuel
additives other than those tested and approved
by us for use on Mercedes-Benz vehicles are not
covered by the Mercedes-Benz Limited
Warranty.
! Add premixed coolant solution only. Adding
water and MB 325.0 Anticorrosion/Antifreeze
separately from each other, could cause engine
damage not covered by the Mercedes-Benz
Limited Warranty.

542 Technical data
Fuels, coolants, lubricants, etc.
Coolant system design and coolant used
determine the replacement interval. The
replacement interval published in the
Maintenance Booklet is only applicable if
MB 325.0 Anticorrosion/Antifreeze solu-
tion or other Mercedes-Benz approved
products of equal specification are used to
renew the coolant concentration or bring it
back up to the proper level.
For information on other Mercedes-Benz
approved products of equal specification,
refer to the Factory Approved Service
Products pamphlet (USA only) or contact
an authorized Mercedes-Benz Light Truck
Center.To provide important corrosion protection,
the solution must be at least
50% anticorrosion/antifreeze (equivalent
to freeze protection to approximately
-35°F [-37°C]). If you use a solution that is
more than 55% anticorrosion/antifreeze
(freeze protection to approximately
-49°F [-45°C]), the engine temperature
will increase due to the lower heat transfer
capability of the solution.
Therefore, do not use more than this
amount of anticorrosion/antifreeze.
If the coolant level is low, water and
MB 325.0 Anticorrosion/Antifreeze
should be used to bring it up to the proper
level (have cooling system checked for
signs of leakage). Please make sure the
mixture is in accordance with label
instructions.The water in the cooling system must meet
minimum requirements, which are usually
satisfied by normal drinking water. If you
are not sure about the water quality,
consult an authorized Mercedes-Benz
Light Truck Center.

549 Index
D
Date display, Setting 176
Daytime running lamp mode 145
Setting 177
Deep water see Standing water
Defogging windshield 216, 230
Defrosting, Front 214, 229
Defrosting, Rear 207
Delayed shut-off
Exterior lamps 179
Interior lighting 180
Department of Transportation see DOT
Diesel engine
Bleeding fuel system 502
Preglow indicator lamp 29
Diesel fuel see Fuel
Difficulties
While driving 62
With starting 55
Digital speedometer 157, 165
Dimensions, Vehicle 534
Direction of rotation (tires) 365Displays
Digital speedometer 157, 165
Distronic* (Canada only) 168, 265
Maintenance service indicator
message 400
Messages in the multifunction
display 427–466
Multifunction display 157
Outside temperature 155, 157, 165
Selecting 175
Showing malfunctions 169
Symbol messages 444
Text messages 429
Vehicle status message memory 169
Vehicle system settings, Control
system 161, 163, 170
Distance to empty (range), Trip
computer 185
Distance warning function* (Canada
only) 185Distronic* (Canada only) 262
Activating 268
Cleaning system sensor 407
Control system 267
Deactivating 271
Distance warning function* 275
Driving hints 273
Messages in the multifunction
display 431
Warning and indicator lamps 265
Door
Entry lamps 153
Locking, In an emergency 475
Locking/unlocking,
KEYLESS-GO* 113
Locking/unlocking, SmartKey 110
Messages in the multifunction
display 452
Opening from the inside 118
Opening from the outside 112
Remote door unlock (Tele Aid*) 328
Unlocking, Mechanical key 474
Door control panel 36
Door handle 36
Door windows see Power windows
DOT 388, 394

556 Index
Lighting
Parking lamps 143
Lighting, Exterior and interior 143
Limp-home mode 202, 417, 418
Loading see Vehicle loading
Loading terminology 393
Locator lighting 146, 178
Lock buttons, KEYLESS-GO*
Outside door handle 68
Loss of keys, Mechanical key 118
Loss of keys, SmartKey 118
Loss of keys, SmartKey with
KEYLESS-GO* 118
Loss of Service and Warranty Information
Booklet 523
Low beam headlamps
Messages in the multifunction
display 455–460
Replacing bulbs 483
switching on 58, 143
Lubricants 536M
Maintenance 12, 400
Calling up service indicator
display 402
Clearing service indicator
message 401
Maintenance System 400
Resetting service indicator 402
Service indicator message 400
Service term exceeded 401
Manual headlamp mode see Headlamps
Maximum cooling, MAXCOOL see Auto-
matic climate control (3-zone)*
Maximum inflation pressure, Tires 395
Maximum load rating, Tires 395
Maximum loaded vehicle weight,
Tires 395
Mechanical key 474
Memory function* 141Menus see Control system menus
Messages in display see Multifunction dis-
play messages
Microphone, Hands-free 33
Mirrors
Adjusting 48
Auto-dimming* 203
Exterior rear view mirrors 48
Interior rear view mirror 48, 203
Mobile phone see Telephone*
MON 540
Multicontour seats* 132
Multifunction display 157
Changing settings see Control system
menus and Control system
submenus
Selecting language 174
Standard display 161