2003 MERCEDES-BENZ C320 COUPE Owner's Manual

289 Practical hints
Flat tire
When changing wheel on a hill:
Place chocks on the downhill side
blocking both wheels of the other axle.

Take the two-piece wheel wrench and
the jack out of the vehicle tool kit
(page 272). Assemble wheel wrench.

On whee l to b e change d, loos en b ut do
not yet remove the wheel bolts (ap-
proximately one full turn with wrench).
The jack take-up brackets are located di-
rectly behind the front wheel housings and
in front of the rear wheel housings.1Jack
2Crank
3Take-up bracket

Place jack on firm ground.

Position jack1 under the take-up
bracket3 so that it is always vertical
(plumb-line) as seen from the side,
even if the vehicle is parked on an in-
cline.

Jack up the vehicle until the wheel is a
maximum of 1.2 in (3 cm) from the
ground. Never start engine while vehi-
cle is raised.
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
firmly set parking brake and block wheels
before raising vehicle with jack.
Do not disengage parking brake while the
vehicle is raised. Be certain that the jack is
always vertical (plumb line) when in use, es-
pecially on hills. Always try to use the jack
on level surface. Make sure that the jack
arm is fully seated in the jack take-up brack-
et. Always lower the vehicle onto sufficient
capacity jackstands before working under
the vehicle.

290 Practical hintsFlat tireRemoving the wheel
1Alignment bolt
Unscrew upper-most wheel bolt and re-
move.

Replace this wheel bolt with the align-
ment bolt1 supplied in the tool kit.

Remove the remaining bolts.

Remove the wheel.

Take the spare tire out of the trunk.
Mounting the new wheel
1Wheel bolt for light alloy rims
2Wheel bolt for light alloy spare wheel
rim size 4
1/2B x15 H2

Clean contact surfaces of wheel and
wheel hub.

Guide the spare wheel onto the align-
ment bolt and push it on.

Insert wheel bolts and tighten them
slightly.

Inflate the spare tire using the electric
pump (
page 292).
!Do not place wheel bolts in sand or dirt.
This could result in damage to the bolt
and wheel hub threads.
!Wheel bolts2 must be used when
mounting spare wheel rim
size 4
1/2B x 15 H2 (
page 313).
The use of any wheel bolts other than
wheel bolts2 for spare wheel rim
size 4
1/2B x15 H2 can cause physical
damage to the vehicle.
Warning!
G
Be sure to use original lenght wheel bolts
when remounting the original wheel after it
has been repaired.Warning!
G
Inflate spare wheel with collapsible tire only
after the wheel is properly mounted.
Inflate the spare wheel tire using the electric
air pump before lowering the vehicle.


291 Practical hints
Flat tire

Unscrew the alignment bolt, install last
wheel bolt and tighten slightly.Lowering the vehicle

Lower vehicle by turning crank coun-
terclockwise until vehicle is resting ful-
ly on its own weight.

Remove the jack.
1-5 Wheel bolts

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 80 ft lb
(110 Nm).
!To avoid paint damage, place wheel flat
against hub and hold it there while in-
stalling first wheel bolt.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 mounting bolts or improperly
tightened mounting bolts can cause the
wheel to come off. This could cause an acci-
dent. Be sure to use the correct mounting
bolts.
Warning!
G
Use only genuine equipment
Mercedes-Benz wheel bolts. They are identi-
fied by the Mercedes star. Other wheel bolts
may come loose.
Do not tighten the wheel bolts when the ve-
hicle is raised. Otherwise the vehicle could
tip over.


292 Practical hintsFlat tire
Before storing the jack in the trunk, it
should be fully collapsed, with handle
folded in.Inflating the spare tire

Take the electric air pump out of the
trunk.
1Flap
2Air hose with pressure gauge and vent
screw
3Union nut
4Electrical plug
Please exercise appropriate caution

Open flap 1 on air pump.

Pull out electrical plug4 and air hose
with the pressure gauge2.
Observe instructions on air pump label.

Remove the valve cap from valve.

Screw the air hose2 on to the tire
valve.

Insert electrical plug 4 into vehicle cig-
arette lighter socket.

To switch on the air pump turn the key
in the starter switch to position1
(page 31).

Operate air pump until the pressure
gauge displays 36 psi (2.5 bar)
This takes about five minutes for the
space tire. The air hose 2 and the union
nut 3 can become hot during inflation.
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
80 ft lb (110 Nm).
Warning!
G
Observe instructions on air pump label.


293 Practical hints
Flat tire

To switch off the air pump turn the key
in the starter switch to position0
(page 31).

If the tire pressure is above 36 psi (2.5
bar), release excess tire pressure using
the vent screw.

Detach the electric air pump.

Store the electrical plug and the air
hose behind the flap and place the air
pump back in the trunk.
!Do not operate the electric air pump
longer than six minutes without inter-
ruption. Otherwise it may overheat.
You may operate the air pump again af-
ter it has cooled off.
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. Underinfalted 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
specified vehicle capacity weight (as indicat-
ed by the label on the driver’s door latch
post). Overloading the tires can overheat
them, possibly causing a blowout.

294 Practical hintsBattery
BatteryThe battery is located in the engine com-
partment on the right hand side.
Removal of filter box:
Release the three clamps1.

Remove filter box.
Installation of filter box:

Insert filter box properly.

Secure it with the three clamps1.
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.
!Never loosen or detach battery termi-
nal clamps while the engine is running
or the key is in the starter switch. Oth-
erwise the alternator and other elec-
tronic components could be severely
damaged.
Have the battery checked regularly by
an authorized Mercedes-Benz Center.
Refer to Service Booklet for mainte-
nance intervals or contact your autho-
rized Mercedes-Benz Center for further
information.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.

295 Practical hints
Battery
Disconnecting the battery
Turn off all electrical consumers.

Open the hood (
page 226).

Remove the filter box.

Disconnect the battery negative lead.

Remove the cover from the positive ter-
minal.

Disconnect the battery positive lead.
Removing the batteries
Remove the screw-nuts securing the
battery.

Remove the battery bracket.

Take out the battery.
Charging and reinstalling batteries
Charge battery in accordance with the
instructions of the battery charger
manufacturer.

Reinstall the charged battery. Follow
the previously described steps in re-
verse order.
Reconnecting the batteries
Turn off all electrical consumers.

Connect the positive lead and fasten its
cover.

Connect the negative lead.

Reinstall the filter box.
Warning!
G
With a disconnected battery

y o u w i l l n o l o n g e r b e a b l e t o t u r n t h e k e y
in the starter switch


the selector lever will remain locked in
positionP
Warning!
G
Never charge a battery while still installed in
the vehicle. Gases may escape during charg-
ing and cause explosions that may result in
paint damage, corrosion or personal injury.
!NEVER invert the terminal connections!!The battery, its filler caps and the vent
tube must always be securely installed
when the vehicle is in operation.

296 Practical hintsBattery
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.
iThe following procedures must be car-
ried out following any interruption of
battery power (e.g. due to reconnec-
tion):

Set the clock (
page 116) (vehi-
cles with COMAND*: see COMAND
operator’s manual).


Resynchronize the ESP
(page 260).


Resynchronize side windows
(page 184).


Resynchronize panorama slid-
ing/pop-up roof (
page 188).