2008 MERCEDES-BENZ S-Class TRUNK

724 Practical hintsFlat tirePreparing the vehicle
Prepare the vehicle as described
(page 723).

Take vehicle tool kit tray and vehicle
jack out of trunk (
page 705).

Take the spare wheel from the wheel
well under the trunk floor
(page 707).
Lifting the vehicle

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 707).
When changing wheel on a level surface:

Place the wheel chock in front of and
another sizeable object behind the
wheel that is diagonally opposite to the
wheel being changed.Always try lifting the vehicle using the jack
on a level surface. However, should cir-
cumstances require you to do so on a hill,
place the wheel chock and another size-
able object as follows:

Place the wheel chock and another
sizeable object on the downhill side
blocking both wheels on the side of the
vehicle not being worked on.

Wheel wrench

On wheel to be changed, loosen but
do not yet remove the wheel bolts
(approximately one full turn with
wrench 1).
Warning!
G
The jack is designed exclusively for jacking
up the vehicle at the jack take-up brackets
built into both sides of the vehicle. To help
avoid personal injury, use the jack only to lift
the vehicle during a wheel change. Never
get beneath the vehicle while it is supported
by the jack. Keep hands and feet away from
the area under the lifted vehicle. Always en-
gage the electronic parking brake and block
wheels before raising vehicle with jack.
Do not disengage electronic parking brake
while the vehicle is raised. Be certain that
the jack is always vertical (plumb line) when
in use, especially on hills. Always try to use
the jack on level surface.
Make sure the jack arm is fully seated in the
jack take-up bracket. Always lower the vehi-
cle onto sufficient capacity jackstands be-
fore working under the vehicle.

726 Practical hintsFlat tireRemoving the wheel
1Alignment bolt
Unscrew upper-most wheel bolt and
remove.

Replace this wheel bolt with alignment
bolt1 supplied in the tool kit.

Remove the remaining bolts.

Remove the wheel.Attaching the spare wheel
1Wheel bolt for light alloy rims and
Minispare wheel with light alloy rim
2Wheel bolt for Minispare wheel with
steel rim (located in trunk with spare
wheel)
!
Do not place wheel bolts in sand or dirt. This
could result in damage to the bolt and wheel hub
threads.
Warning!
G
Always replace wheel bolts that are dam-
aged or rusted.
Never apply oil or grease to wheel bolts.
Damaged wheel hub threads should be re-
paired immediately. Do not continue to drive
under these circumstances! Contact an au-
thorized Mercedes-Benz 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 you are using 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 ve-
hicle is raised. Otherwise the vehicle could
fall off the jack.

728 Practical hintsFlat tire6Wheel wrench
Tighten the five wheel bolts evenly, fol-
lowing the diagonal sequence illustrat-
ed (1 to 5), until all bolts are tight.
Observe a tightening torque of
110 lb-ft (150 Nm).

Fully collapse the jack, with handle
folded in (storage position),
(page 706).

Store the jack and the other vehicle
tools in the designated storage space
underneath the trunk floor
(page 705).
Warning!
G
Have the tightening torque checked after
changing a wheel. The wheels could come
loose if they are not tightened to a torque of
110 lb-ft (150 Nm).i
Vehicles with Advanced TPMS:
Do not activate the tire inflation pressure moni-
tor until a full size wheel/tire with functioning
sensor has been placed back into service on the
vehicle.

729 Practical hints
Batteries
Batteries
Your vehicle is equipped with two batter-
ies:

The starter battery, located in the en-
gine compartment


The battery for electrical consumers
(consumer battery), located in the
trunk
The batteries should always be sufficiently
charged in order to achieve its rated ser-
vice life. Refer to Maintenance Booklet for
battery maintenance intervals.
If you use your vehicle mostly for short-dis-
tance trips, you will need to have the bat-
tery charge checked more frequently.
When replacing the batteries, 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.
Large 12-volt storage batteries contain
lead. Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
!
Do not tow-start the vehicle.
Warning!
G
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
faceguard.
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
Operator’s Manual.

730 Practical hintsBatteries!
The consumer battery located in the trunk is
a valve-r
egulated l
ead a
cid (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 consumer battery as other-
wise the battery will be damaged.
Even though VRLA batteries do not require top-
ping-up of the electrolyte level and cannot be
opened to check the electrolyte level, the bat-
tery condition must be checked periodically by
performing a battery conductance test. Refer to
Maintenance Booklet for battery condition test-
ing intervals.
As with any other battery, disconnect the con-
sumer battery if you do not intend to operate
your vehicle for an extended period of time to
prevent battery discharge or connect an acces-
sory battery charge unit expressly approved by
Mercedes-Benz for your vehicle model to main-
tain the battery charge. Contact an authorized
Mercedes-Benz Center for further 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 facto-
ry-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
Failure to follow these instructions can re-
sult in severe injury or death.
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.Warning!
G
Do not place metal objects on the battery as
this could result in a short circuit.
Use leak-proof battery only to avoid the risk
of acid burns in the event of an accident.
Take care that you do not become statically
charged, e.g. by wearing synthetic clothing
or rubbing against textiles. For this reason,
you also should not pull or push the battery
over carpets or other synthetic materials.
Never touch the battery first. First touch the
outside body of the vehicle in order to re-
lease any possible electrostatic charges.

731 Practical hints
Batteries
Starter battery (example illustration from
S 550)1Negative terminal
2Positive terminal
Disconnecting starter battery
Secure vehicle in place with electronic
parking brake (
page 422).

Shift the automatic transmission to
park positionP (
page 426).
Do not rub the battery with rags or cloths.
The battery could explode if touched due to
electrostatic charge or due to spark forma-
tion.!
Switch off the engine and switch off the ve-
hicle’s internal electrical functions (
page 732)
before you disconnect or remove the battery’s
terminal clamps. You could otherwise destroy
electronic assemblies such as the generator.
Have the battery checked regularly by an autho-
rized Mercedes-Benz Center. Refer to Mainte-
nance Booklet for maintenance intervals or
contact an authorized Mercedes-Benz Center for
further information.
!
Do not connect any consumers directly to
the starter battery. The starter battery will other-
wise be discharged.
i
Only replace a discharged battery with a bat-
tery recommended by Mercedes-Benz. The con-
sumer battery is installed in the trunk in such a
way that it is safeguarded as much as possible
against mechanical destruction in the event of
an accident.
i
Remove SmartKey from starter switch (vehi-
cles with KEYLESS-GO*: Make sure the vehicle’s
on-board electronics have status 0)
(
page 370) when you turn off the engine and
no longer require any electrical consumers. The
vehicle then uses very little power and the con-
sumer battery is spared.
i
If the consumer battery is discharged, you
must use the mechanical key to unlock the vehi-
cle (page 708). Since the vehicle has a sepa-
rate starter battery, however, you can still start
the vehicle.
!
Always disconnect the starter battery in the
order described below. You could otherwise
damage the vehicle’s electronics.
!
Switch off the vehicle’s internal electrical
functions before disconnecting the starter bat-
tery. If the vehicle is stationary for more than one
hour with the SmartKey removed, you do not
need to switch off the vehicle’s internal electrical
functions.

733 Practical hints
Batteries
Starter battery
Connect the switched-off charging de-
vice to the terminals of the starter bat-
tery. Observe the operating
instructions in the manual for the
charging device while doing so.
Reinstalling starter battery
Install starter battery in engine com-
partment.

Swing retaining bar down.
Reconnecting starter battery

Make sure that the consumer battery in
the trunk is correctly installed and con-
nected.

Turn SmartKey in starter switch to po-
sition 0 and remove.

Connect the positive lead and fasten its
cover2 (
page 731).

Connect negative lead1
(page 731).

Attach ventilation tube.

Switch on the ignition (
page 370).

Start the engine (
page 416).

Check vehicle functions.
!
Only use charging devices with a maximum
charging voltage of 14.8 V.
Warning!
G
During the charge procedure, there is a risk
of acid burns due to gases escaping from
the battery. Do not bend over the battery
during the charge procedure.
!
The battery and the battery ventilation hose
must always be securely installed when the vehi-
cle is in operation.
!
Always connect the starter battery in the or-
der described below. Otherwise, the vehicle’s
electronics could be damaged.
Warning!
G
Do not drive without a properly installed and
connected consumer battery.
Have any work on the consumer battery car-
ried out by an authorized Mercedes-Benz
Center.
!
Never invert the terminal connections.
!
Make sure that the battery has a plug where
the ventilation tube is attached to it.

740 Practical hintsTowing the vehicleInstalling towing eye bolt
1Cover on right side of front bumper
1Cover on right side of rear bumperRemoving cover

Press mark on cover1 in the direction
of arrow.

Lift cover off to reveal the threaded
hole for towing eye bolt.
Installing towing eye bolt

Take towing eye bolt and wheel wrench
out of the vehicle tool kit in the trunk
(page 705).

Screw towing eye bolt clockwise into
its stop and tighten with wheel wrench.Removing towing eye bolt

Loosen towing eye bolt counterclock-
wise with wheel wrench.

Unscrew towing eye bolt.

Store towing eye bolt and wheel
wrench in the vehicle tool kit in the
trunk.
Installing cover

Fit cover1 and snap into place.