MERCEDES-BENZ R320 2008 W251 Owner's Manual

490 Practical hints
Replacing wiper blades
Installing
1Wiper blade
2Attachment
3Guide tab
4Opening
With guide tab 3 sliding into
opening4, place wiper blade 1 onto
wiper arm in direction of arrow.
Fold wiper blade 1 towards wiper
arm.
Tabs 2 (
page 489) must engage
into both recesses of attachment 2.
Check whether the wiper blade is
securely fastened.
Fold the wiper arm backward to rest on
the windshield.
Make sure to hold on to the wiper when
folding the wiper arm back.
Rear wiper blade
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*
Make sure the vehicle’s on-board
electronics have status0
(
page 41).
!Make sure the wiper blades are properly in-
stalled. Improperly installed wiper blades may
cause windshield damage.
!Hold on to the wiper when folding the wiper
arm back. If released, the force of the impact
from the tensioning spring could crack the rear
window.
Do not allow the wiper arm to contact the rear
window glass without a wiper blade inserted.
For your convenience, we recommend that you
have this work carried out by an authorized
Mercedes-Benz Light Truck Center.

491 Practical hints
Replacing wiper blades
Removing
1Wiper arm
2Wiper blade
Fold wiper arm 1 away from the rear
window until it engages.
Turn wiper blade2 to form a right
angle with wiper arm 1 as shown.
Hold wiper arm 1 and disengage
wiper blade 2 by carefully sliding it in
direction of arrow.
Remove wiper blade 2.Installing
1Wiper arm
2Wiper blade
Insert wiper blade 2 into wiper
arm1.
Hold wiper arm 1 and engage wiper
blade 2 by pushing it in direction of
arrow until it locks into place.
Check whether the wiper blade is
securely fastened.
Fold the wiper arm to rest on the rear
window.
Make sure to hold on to the wiper when
folding the wiper arm back.
!Do not pull on the wiper blade insert. It
could tear.
!Make sure the wiper blade is properly
installed. An improperly installed wiper blade
may cause windshield damage.

492 Practical hints
Flat tire
Preparing the vehicle
Vehicles with AIRMATIC*:
Make sure the vehicle level is set to
highway level (
page 276).
Park the vehicle in a safe distance from
moving traffic on a hard, flat surface
when possible.
Turn on the hazard warning flasher
(
page 150).
Turn the steering wheel so that the
front wheels are in a straight-ahead
position.
Set the parking brake (page 65).
Set the automatic transmission to
position P (
page 190).
Turn off the engine (page 66).
Have any passenger exit the vehicle at
a safe distance from the roadway.
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*:
Turn off the engine by pressing the
KEYLESS-GO* button once
(
page 66).
Open the driver’s door (this puts
the starter switch in position 0,
same as with the SmartKey re-
moved from the starter switch). The
driver’s door then can be closed
again.
Remove the KEYLESS-GO*
start/stop button from the starter
switch.
Warning!G
The dimensions of the spare wheel are
different from those of the road wheels. As
a result, the vehicle handling characteristics
change when driving with a spare wheel
mounted. Adapt your driving style accord-
ingly.
The spare wheel is for temporary use only.
When driving with spare wheel mounted,
ensure proper tire inflation pressure and do
not exceed a vehicle speed of
50 mph (80 km/ h).
Drive to the nearest Mercedes-Benz Light
Truck Center as soon as possible to have the
spare wheel replaced with a regular road
wheel.
Never operate the vehicle with more than
one spare wheel mounted.
Do not switch off the ESP
® with a spare
wheel mounted.
iOpen doors only when conditions are safe to
do so.

493 Practical hints
Flat tire
Mounting the spare wheel
Preparing the vehicle
Prepare the vehicle as described
(
page 492).
Take the wheel wrench and the vehicle
jack from the vehicle tool kit
(
page 469).
Take the spare wheel from the wheel
well under the cargo compartment
floor (
page 472).Lifting the vehicle
iYou can use the power outlets, except for
the power outlet in the front center console, to
operate the electric air pump even when the
ignition is switched off, e.g. in order to inflate the
collapsible tire (
page 499).
An emergency shut-off feature ensures that the
vehicle’s electrical voltage does not fall below a
minimum level. If the voltage drops to this mini-
mum level, the power outlets are automatically
switched off. This ensures that enough power
remains to start the engine.
Warning!G
When jacking up the vehicle, only use the
jack which has been specifically approved
by Mercedes-Benz for your vehicle.
The jack is designed exclusively for jacking
up the vehicle at the jack take-up brackets
built into both sides of the vehicle. Make
sure the jack arm is fully seated in the jack
take-up bracket.
The jack is intended only for lifting the
vehicle briefly for wheel changes. It is not
suited for performing maintenance work
under the vehicle. To help avoid personal in-
jury, use the jack only to lift the vehicle dur-
ing a wheel change.
Never get beneath the vehicle while it is sup-
ported by the jack. Keep hands and feet
away from the area under the lifted vehicle.
Always lower the vehicle onto sufficient
capacity jackstands before working under
the vehicle.


494 Practical hints
Flat tire
Prevent the vehicle from rolling away
by blocking wheels with wheel chocks
or other sizeable objects.
One wheel chock is included with the
vehicle tool kit (
page 469).Changing wheel on a level surface
Changing rear wheel on passenger side
(Example illustration)
Place the wheel chock in front of and
another sizeable object behind the
wheel that is diagonally opposite to the
wheel being changed.
Always firmly set parking brake and block
wheels with wheel chocks or other sizeable
objects before raising vehicle with jack. Do
not disengage parking brake while the vehi-
cle is raised.
Make sure that the ground on which the
vehicle is standing and where you place the
jack is solid, level and not slippery. If neces-
sary, use a large underlay. On slippery
surfaces, such as tiled floors, you should
use a non-slip underlay, for example a
rubber mat.
Do not use wooden blocks or similar objects
to support the jack. Otherwise the jack may
not be able to achieve its load-bearing
capacity if it is not at its full height.
Never start the engine when the vehicle is
raised.
Also observe the notes on the jack.
Warning!G
Only jack up the vehicle on level ground or
on slight inclines/declines. Otherwise, the
vehicle could fall off the jack and injure you
or others.


495 Practical hints
Flat tire
Changing wheel on a slight decline
Always try lifting the vehicle using the jack
on a level surface. However, should
circumstances require you to do so on a
slight decline, place the wheel chock and
another sizeable object as follows:
Changing wheel on passenger side
(Example illustration)
Place wheel chock (or another sizeable
object) in front of both wheels on the
side opposite to the side on which the
wheel is to be changed.Changing wheel on a slight incline
Always try lifting the vehicle using the jack
on a level surface. However, should
circumstances require you to do so on a
slight incline, place the wheel chock and
another sizeable object as follows:
Changing wheel on passenger side
(Example illustration)
Place wheel chock (or another sizeable
object) behind both wheels on the side
opposite to the side on which the wheel
is to be changed.1Wheel wrench
On wheel to be changed, loosen but do
not yet remove the wheel bolts
(approximately one full turn with wheel
wrench 1).

496 Practical hints
Flat tire
The jack take-up brackets are located
directly behind the front wheel housings
and in front of the rear wheel housings as
indicated by the arrows.Depending on production date, your vehi-
cle may be equipped with either a
screw-type vehicle jack or a scissors-type
jack, see “Vehicle jack” (
page 469).
Screw-type jack
2Take-up bracket
3Jack
4Crank
Scissors-type jack
2Take-up bracket
3Jack
4Ratchet
Vehicles with scissors-type jack:
Attach reversible ratchet4 to vehicle
jack in such a way that the wordUP
can be seen.
Place jack 3 on firm ground.
Position jack3 under take-up
bracket2 so that it is always vertical
(plumb-line) as seen from the side,
even if the vehicle is parked on an
incline.
Warning!G
The jack is designed exclusively for
jacking up the vehicle at the jack take-up
brackets. Make sure the jack arm is fully
seated in the jack take-up bracket.
If you do not position the jack correctly in
the jack take-up bracket, the vehicle can:

fall off the jack

seriously or fatally injure you or others
!Do not position the jack on the body of the
vehicle, as this may cause damage to the
vehicle.

497 Practical hints
Flat tire
Screw-type jack (example illustration)
Scissors-type jack (example illustration)
Vehicles with screw-type jack: Turn
crank4 clockwise until jack 3 is fully
seated in take-up bracket2 and the
jack base evenly meets the ground.
Vehicles with scissors-type jack:
Turn ratchet 4 up and down until
jack3 is fully seated in take-up
bracket2 and the jack base evenly
meets the ground.
Continue to turn crank/ratchet 4
until the wheel is a maximum of
1.2 in (3 cm) from the ground.Removing the wheel
1Alignment bolt
Unscrew upper-most wheel bolt and
remove.
Replace this wheel bolt with alignment
bolt1 supplied in the vehicle tool kit
(
page 467).
Remove the remaining wheel bolts.
Remove the wheel.
!Do not place wheel bolts in sand or dirt. This
could result in damage to the bolts and wheel
hub threads.

498 Practical hints
Flat tire
Mounting the spare wheel
1Wheel bolt for 18", 19", and 20" light al-
loy wheels
2Wheel bolt for spare wheel (located in
cargo compartment with spare wheel)
Clean contact surfaces of wheel and
wheel hub.
Guide spare wheel onto the alignment
bolt and push it on.
Insert wheel bolts and tighten them
slightly.
Unscrew the alignment bolt, install last
wheel bolt and tighten slightly.
!Wheel bolts2 must be used when mount-
ing the spare wheel with collapsible tire.
The use of any wheel bolts other than wheel
bolts2 for the spare wheel with collapsible tire
will physically damage the vehicle’s brakes.
!To avoid paint damage, place wheel flat
against hub and hold it there while installing first
wheel bolt.
Warning!G
Always replace wheel bolts that are
damaged or rusted.
Never apply oil or grease to wheel bolts.
Damaged wheel hub threads should be
repaired immediately. Do not continue to
drive under these circumstances! Contact
an authorized Mercedes-Benz Light Truck
Center or call Roadside Assistance.
Incorrect wheel bolts or improperly tight-
ened wheel bolts can cause the wheel to
come off. This could cause an accident.
Make sure to use the correct wheel bolts.
Warning!G
Only use genuine Mercedes-Benz wheel
bolts. Other wheel bolts may come loose.
Do not tighten the wheel bolts when the
vehicle is raised. Otherwise the vehicle
could fall off the jack.

499 Practical hints
Flat tire
Inflating the collapsible tire
Take the electric air pump out of the
vehicle tool kit storage well
(
page 467).
Electric air pump
1Flap
2On/off switch
3Electrical plug
4Air hose with pressure gauge and vent
screw
5Union nut
Open flap 1 on electric air pump.
Pull out electrical plug 3 and air hose
with pressure gauge 4.
Remove the valve cap from the
collapsible tire valve.
Screw union nut 5 onto the
collapsible tire valve.
Insert electrical plug 3 into a power
outlet (
page 314).
Turn the SmartKey in the starter switch
to position1.
Vehicles with KEYLESS-GO*:
Press the KEYLESS-GO start/stop
button once without depressing the
brake pedal.
Press I on electric air pump switch 2.
The electric air pump should now
switch on and inflate the collapsible
tire.
Warning!G
Inflate collapsible tire only after the wheel is
properly mounted.
Inflate the collapsible tire using the electric
air pump (
page 467) before lowering the
vehicle.
Warning!G
Observe instructions on air pump label.
!Do not lower the vehicle before inflating the
collapsible tire. Otherwise the rim may be dam-
aged.
!The cigarette lighter (page 312) is not de-
signed for use with the electric air pump. Use a
power outlet (
page 314) for electric air pump
operation.