brake MERCEDES-BENZ R350 2006 W251 Service Manual

303 Controls in detail
Useful features
Ashtray in the front center console
Opening the ashtray
1Cover
2Chrome label
Tab lightly on chrome label 2 of
cover1.
Cover 1 swings open.Removing ashtray insert
1Cover plate
2Ashtray insert

Grip ashtray insert 2 on the sides and
pull it out upwards.
Reinstalling ashtray insert

Insert ashtray insert 2 and push down
until the ball catch engages.

Close ashtray cover plate 1.
Warning!
G
Remove ashtray only with vehicle standing
still. Set the parking brake to secure vehicle
from movement. Set automatic transmis-
sion toP. With the automatic transmission
set toP, turn off the engine.

331 Operation
Driving instructions
Driving instructions
Drive sensibly – save fuel
Fuel consumption, to a great extent,
depends on driving habits and operating
conditions.
To save fuel you should:

Keep tires at the recommended infla-
tion pressures.


Remove unnecessary loads.


Remove roof rack when not in use.


Allow engine to warm up under low
load use.


Avoid frequent acceleration and decel-
eration.


Have all maintenance work performed
at the intervals specified in the Mainte-
nance Booklet and as required by the
Maintenance System (U.S. vehicles) or
FSS PLUS (Canada vehicles). Contact
an authorized Mercedes-Benz Light
Truck Center.Fuel consumption is also increased by
driving in cold weather, in stop-and-go
traffic, on short trips and in hilly area.
Drinking and driving
PedalsPower assistance
Warning!
G
Drinking and driving and/or taking drugs
and driving are a very dangerous combina-
tion. Even a small amount of alcohol or
drugs can affect your reflexes, perceptions
and judgment.
The possibility of a serious or even fatal
accident are greatly increased when you
drink or take drugs and drive.
Do not drink or take drugs and drive or allow
anyone to drive who has been drinking or
taking drugs.
Warning!
G
Keep driver’s foot area clear at all times. Ob-
jects stored in this area may impair pedal
movement.Warning!
G
With the engine not running, there is no
power assistance for the brake and steering
systems. In this case, it is important to keep
in mind that a considerably higher degree of
effort is necessary to brake and steer the ve-
hicle.

332 OperationDriving instructionsBrakesTo help prevent brake disk corrosion after
driving on wet road surfaces (particularly
salted roads), it is advisable to brake the
vehicle with considerable force prior to
parking. The heat generated serves to dry
the brakes.
If your brake system is normally only sub-
jected to moderate loads, you should occa-
sionally test the effectiveness of the
brakes by applying above-normal braking
pressure at higher speeds. This will also
enhance the grip of the brake pads.
Refer to the description of the Brake Assist
System (BAS) (
page 99).If the parking brake is released and the
brake warning lamp in the instrument clus-
ter stays on and there is no audible warn-
ing (EBP), the brake fluid level in the
reservoir is too low.
Brake pad wear or a leak in the system may
be the reason for low brake fluid in the
reservoir.
Have the brake system inspected immedi-
ately. Contact an authorized
Mercedes-Benz Light Truck Center.
All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact an authorized
Mercedes-Benz Light Truck Center.
Only install brake pads and brake fluid
recommended by Mercedes-Benz.
Warning!
G
After driving in heavy rain for some time
without applying the brakes or through wa-
ter deep enough to wet brake components,
the first braking action may be somewhat
reduced and increased pedal pressure may
be necessary to obtain expected braking ef-
fect. Maintain a safe distance from vehicles
in front.
Resting your foot on the brake pedal will
cause excessive and premature wear of the
brake pads.
It can also result in the brakes overheating,
thereby significantly reducing their effec-
tiveness. It may not be possible to stop the
vehicle in sufficient time to avoid an acci-
dent.
Warning!
G
Make sure not to endanger any other road
users when carrying out these braking
maneuvers.

333 Operation
Driving instructions
After hard braking, it is advisable to drive
on for some time, rather than immediately
park, so that the air stream will cool down
the brakes faster.
Driving off
Apply the brakes to test them briefly after
driving off. Perform this procedure only
when the road is clear of other traffic.
Warm up the engine smoothly. Do not
place full load on the engine until the oper-
ating temperature has been reached.
When starting off on a slippery surface, do
not allow a drive wheel to spin for an
extended period with the ESP
® switched
off. Doing so may cause serious damage to
the drivetrain which is not covered by the
Mercedes-Benz Limited Warranty.
Warning!
G
If other than recommended brake pads are
installed, or other than recommended brake
fluid is used, the braking properties of the
vehicle can be degraded to an extent that
safe braking is substantially impaired. This
could result in an accident.
!When driving down long and steep
grades, relieve the load on the brakes
by shifting into a lower gear to use the
engine’s braking power. This helps
prevent overheating of the brakes and
reduces brake pad wear.
When using the engine’s braking pow-
er, a drive wheel may not spin for an ex-
tended period of time, e.g. on slippery
road surfaces. This may cause serious
damage to the drivetrain which is not
covered by the Mercedes-Benz Limited
Warranty.
!Simultaneously depressing the
accelerator pedal and applying the
brake reduces engine performance and
causes premature brake and drivetrain
wear.

334 OperationDriving instructionsParking
Tires
Treadwear indicators (TWI) are required by
law. These indicators are located in six
places on the tread circumference and
become visible at a tread depth of
approximately
1/16
in (1.6 mm), at which
point the tire is considered worn and
should be replaced.
!Set the parking brake whenever park-
ing or leaving the vehicle. In addition,
set the automatic transmission to
positionP.
When parking on hills, always turn front
wheels towards the curb.Warning!
G
To reduce the risk of personal injury, or
damage to the vehicle powertrain, as a
result of vehicle movement, before turning
off the engine and leaving the vehicle al-
ways:

Keep right foot on brake pedal.


Firmly depress parking brake pedal.


Set the automatic transmission to
positionP.


When parked on an incline, turn front
wheel towards the road curb.


Turn the SmartKey to starter switch
position0 and remove, or press
KEYLESS-GO* start / stop button (vehi-
cles with KEYLESS-GO*).


Take the SmartKey or the SmartKey with
KEYLESS-GO* with you and lock vehicle
when leaving.
Warning!
G
If you feel a sudden significant vibration or
ride disturbance, or you suspect that possi-
ble damage to your vehicle has occurred,
you should turn on the hazard warning flash-
ers, carefully slow down, and drive with cau-
tion to an area which is a safe distance from
the road.
Inspect the tires and the vehicle underbody
for possible damage. If the vehicle or tires
appear unsafe, have the vehicle towed to
the nearest Mercedes-Benz Light Truck
Center or tire dealer for repairs.

335 Operation
Driving instructions
The treadwear indicator appears as a solid
band across the tread.
Specified tire pressures must be main-
tained. This applies particularly if the tires
are subjected to high loads (e.g. high
speeds, heavy loads, high ambient temper-
atures).
Hydroplaning
Depending on the depth of the water layer
on the road, hydroplaning may occur, even
at low speeds and with new tires. Reduce
vehicle speed, avoid track grooves in the
road and apply brakes cautiously in the
rain.
Tire traction
The safe speed on a wet, snow covered or
icy road is always lower than on a dry road.
You should pay particular attention to the
condition of the road whenever the outside
temperatures are close to the freezing
point.
Warning!
G
Although the applicable federal motor
vehicle safety laws consider a tire to be
worn when the treadwear indicators (TWI)
become visible at approximately
1/16in
(1.6 mm), we recommend that you do not
allow your tires to wear down to that level.
As tread depth approaches
1/8in (3 mm),
the adhesion properties on a wet road are
sharply reduced.
Depending upon the weather and/or road
surface (conditions), the tire traction varies
widely.
Warning!
G
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle. You
may lose control of the vehicle. Continued
driving with a flat tire or driving at high
speed with a flat tire will cause excessive
heat build-up and possibly a fire.
Warning!
G
If ice has formed on the road, tire traction
will be substantially reduced. Under such
weather conditions, drive, steer and brake
with extreme caution.

337 Operation
Driving instructions
Winter driving instructions
The most important rule for slippery or icy
roads is to drive sensibly and to avoid
abrupt acceleration, braking and steering
maneuvers. Do not use the cruise control
system under such conditions.
When the vehicle is in danger of skidding,
move gear selector lever to positionN. Try
to keep the vehicle under control by
corrective steering action.Road salts and chemicals can adversely af-
fect braking efficiency. Increased pedal
force may become necessary to produce
the normal brake effect.
Depressing the brake pedal periodically
when traveling at length on salt-strewn
roads can bring road-salt-impaired braking
efficiency back to normal.
If the vehicle is parked after being driven
on salt-treated roads, the braking efficien-
cy should be tested as soon as possible af-
ter driving is resumed.
For more information, see “Winter driving”
(
page 390).
iFor information on driving with snow
chains, see “Snow chains”
(page 391).
Warning!
G
On slippery road surfaces, never downshift
in order to obtain braking action. This could
result in drive wheel slip and reduced vehi-
cle control. Your vehicle’s ABS will not pre-
vent this type of control loss.
Warning!
G
Make sure not to endanger any other road
users when carrying out these braking
maneuvers.
Warning!
G
If the vehicle becomes stuck in snow, make
sure that snow is kept clear of the exhaust
pipe and from around the vehicle with the
engine running. Otherwise, deadly carbon
monoxide (CO) gases may enter vehicle in-
terior resulting in unconsciousness and
death.
To assure sufficient fresh air ventilation,
open a window slightly on the side of the ve-
hicle not facing the wind.Warning!
G
The outside temperature indicator is not de-
signed to serve as an ice-warning device and
is therefore unsuitable for that purpose. In-
dicated temperatures just above the freez-
ing point do not guarantee that the road
surface is free of ice.

343 Operation
At the gas station

Replace the fuel cap by turning it clock-
wise until it audibly engages.

Close the fuel filler flap.
Check regularly and before a long trip
Open the hood (
page 345).
1Coolant level
2Brake fluid
3Windshield washer system and
headlamp cleaning system*
Engine oil level
For more information on engine oil, see
“Engine oil” (
page 346).
iOnly use premium unleaded gasoline
with a minimum Posted Octane Rating
of 91 (average of 96 RON / 86 MON).
Information on gasoline quality can
normally be found on the fuel pump.
For more information on gasoline, see
the Factory Approved Service Products
pamphlet.
iLeaving the engine running and the fuel
cap open can cause the yellow fuel
tank reserve warning lamp to flash and
the? malfunction indicator lamp
(USA only) or the± malfunction in-
dicator lamp (Canada only) comes on.
For more information, see “Practical
hints” (
page 408).

344 OperationAt the gas stationCoolant
For normal replenishing, use water (pota-
ble water quality). For more information,
see “Coolant level” (
page 351) and
“Fuels, coolants, lubricants, etc.”
(
page 521).
Brake fluidWindshield / rear window washer
system and headlamp cleaning
system*
For more information on refilling the reser-
voir, see “Windshield / rear window washer
system and headlamp cleaning system*”
(
page 352).
Vehicle lighting
Check function and cleanliness. For infor-
mation on replacing light bulbs, see “Re-
placing bulbs” (
page 465).
For more information, see “Exterior lamp
switch” (
page 147).
Tire inflation pressure
For more information, see “Checking tire
inflation pressure” (
page 365).
!If you find that the brake fluid in the
brake fluid reservoir has fallen to the
minimum mark or below, have the
brake system checked for brake pad
thickness and leaks immediately. Noti-
fy an authorized Mercedes-Benz Light
Truck Center immediately. Do not add
brake fluid as this will not solve the
problem. For more information, see
“Brake fluid” (
page 523).

353 Operation
Tires and wheels
Tires and wheels
See an 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
purchase.
Retreaded tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on
retreads. The operating safety of the
vehicle cannot be assured when such tires
are used.
Important guidelines

Only use 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 inflation pressure loss and
damage to the tire beads.


If vehicle is heavily loaded, check tire
inflation 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 an authorized
Mercedes-Benz Light Truck Center for fur-
ther information. If incorrectly sized rims
and tires are mounted:

The wheel brakes or suspension
components can be damaged.


The operating clearance of the wheels
and the tires may no longer be correct.
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, only use genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can
result in the bolts loosening and possibly an
accident.