air condition MERCEDES-BENZ ML350 1997 Complete Service Manual

174
Driving instructions
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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 inflation pressures,
• remove unnecessary loads,
• remove roof rack when not in use,
• allow engine to warm up under low load use,
• avoid frequent acceleration and deceleration,
• have all maintenance work performed at regular
intervals by 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
country. Drinking and driving
Pedals
Wa r n i n g !
Drinking or taking drugs and driving can be a very
dangerous combination. Even a small amount of
alcohol or drugs can affect your reflexes,
perceptions and judgement.The possibility of a serious or even fatal accident is
sharply increased when you drink or take drugs
and drive.Please don’t drink or take drugs and drive or allow
anyone to drive after drinking or taking drugs.Wa r n i n g !
Keep driver’s foot area clear at all times. Objects
stored in this area may impair pedal movement.

175
Driving instructions
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Power assistance
Brakes The condition of the parking brake system is checked
each time the vehicle is in the shop for the required
maintenance service.
If the parking brake is released and the brake warning
lamp in the instrument cluster stays on and there is no
audible warning (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 f luid in the reservoir.
Have the brake system inspected at an authorized
Mercedes-Benz Light Truck Center immediately.
All checks and service work on the brake system should
be carried out by an authorized Mercedes-Benz Light
Truck Center.
Install only brake pads and brake fluid recommended by
Mercedes-Benz.
Wa r n i n g !
When the engine is not running, the brake and
steering systems are without power assistance.
Under these circumstances, a much greater effort is
necessary to stop or steer the vehicle.Wa r n i n g !
After driving in heavy rain for some time without
applying the brakes or through water 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 effect. Be sure to 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 effectiveness. It may
not be possible to stop the vehicle in sufficient time
to avoid an accident.
Wa r n i n 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.

177
Driving instructions
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Tires
Tread wear 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
1/16in (1.5 mm), at which point the tire is
considered worn and should be replaced.
The tread wear indicator appears as a solid band across
the tread.
Wa r n i n g !
If you feel a sudden significant vibration or ride
disturbance, or you suspect that possible damage to
your vehicle has occurred, you should turn on the
hazard warning f lashers, carefully slow down, and
drive with caution to an area which is a safe
distance from the roadway.Inspect the tires and under the vehicle for possible
damage. If the vehicle or tires appear unsafe, have
it towed to the nearest Mercedes-Benz Light Truck
Center or tire dealer for repairs.
Wa r n i n g !
Do not allow your tires to wear down too far. As
tread depth approaches
1/16in (1.5 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.

180
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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
selector lever to position “N”. Try to keep the vehicle
under control by corrective steering action.
Caution!
Do not use LOW RANGE mode when driving on ice or
packed snow. At speeds below 18 mph (30 km / h)
vehicle steering is adversely affected by the LOW
RANGE ABS.
Road salts and chemicals can adversely affect braking
efficiency. Increased pedal force may become necessary
to produce the normal brake effect. We therefore
recommend depressing the brake pedal periodically
when traveling at length on salt-strewn roads. This can
bring road salt impaired braking efficiency back to
normal. A prerequisite is, however, that this be done
without endangering other drivers on the road. If the vehicle is parked after being driven on salt treated
roads, the braking efficiency should be tested as soon as
possible after driving is resumed while observing the
safety rules in the previous paragraph.
Wa r n i n 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 engine running.
Otherwise, deadly carbon monoxide (CO) gases may
enter vehicle interior resulting in unconsciousness
and death.To assure sufficient fresh air ventilation, open a
window slightly on the side of the vehicle not
facing the wind.

195
Driving instructions
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At very steep inclines, not manageable with selector
lever in position “1”, switch transfer case to LOW
RANGE, see page 209 for instructions on how to engage
LOW RANGE.
When going down a long hill, shift into a lower gear and
use the engine’s braking effect. Avoid riding the brakes,
thus overheating the vehicle and trailer brakes.
If the engine coolant rises to an extremely high
temperature (coolant temperature needle approaching
the red zone) when the air conditioner is on, turn off the
air conditioner. Engine coolant heat can be additionally
vented by opening the windows, switching the climate
control fan speed to high and setting the temperature
control to the maximum hot position.
Extreme care must be exercised since your vehicle with
a trailer will require additional passing distance ahead
than when driving without a trailer. Because your
vehicle and trailer is longer than your vehicle alone, you
will also need to go much farther ahead of the passed
vehicle before you can return to your lane. Parking
Wa r n i n g !
To reduce the risk of personal injury, or damage to
the vehicle powertrain, as a result of vehicle/trailer
movement, always:1. Keep right foot on brake pedal.2. Shift gear selector lever to position “N”.3. Have a second person place wheel chocks on
downhill side of left and right trailer wheels.4. Slowly release brake pedal and let vehicle and trailer roll into chocks until stopped.5. Firmly depress parking brake pedal.6. Move gear selector lever to position “P”.7. On inclines turn front wheels towards the road curb.

213
What you should know at the gas station
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Leaving the engine running and the fuel cap open can
cause the “CHECK ENGINE” lamp to illuminate.
Fuel tank capacity approximately 19.0 US gal (72.0 l).
This includes approximately 3.2 US gal (12.0 l) reserve.
Use premium unleaded gasoline: Posted Octane
Index 91 (Average of 96 RON / 86 MON).
•Engine oil Engine oil level check, see page 89 and page 233.
Fill quantity between upper and lower dipstick
marking level: 2.1 US qt (2.0 l).
Recommended engine oils, see Approved Service
Products sheet. • Coolant
For normal replenishing, use water (potable water
quality).
For further information (e.g. anticorrosion/
antifreeze), see page 292.
• Spark plugs Approved spark plugs, see page 290.
• Tire pressure For tire pressure, refer to tire pressure label inside
the fuel filler flap. See page 250 for further details.
• Air conditioner R-134a refrigerant and special PAG lubricant, see
page 294.
Wa r n i n g !
Overfilling of fuel tank may result in creating
pressure in the system which could cause a gas
discharge such as the gas spraying back out upon
removing the filler nozzle which could cause
personal injury.

223
Malfunction and indicator lamps
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Seat belt warning lamp
With the key in steering lock position 2, the
seat belt warning lamp comes on for a short
time if the driver’s seat belt is not fastened.
After starting the engine, the warning lamp remains
illuminated for a short time to remind the driver and
passengers to fasten seat belts.
Charge indicator lamp Should the charge indicator lamp fail to
come on prior to starting when the key is in
steering lock position 2 or should it fail to go
out after starting or during operation, this indicates a
malfunction which must be repaired at an authorized
Mercedes-Benz Light Truck Center immediately. If the charge indicator lamp comes on while the engine
is running, this may indicate that the poly-V-belt has
broken. Should this condition occur, the poly-V-belt
must be replaced before continuing to operate the
vehicle. Otherwise, the engine will overheat due to an
inoperative water pump which may result in damage to
the engine.
Do not continue to drive the vehicle with the charge
indicator lamp illuminated. Doing so could result in
serious engine damage that is not covered by the
Mercedes-Benz Limited Warranty.

250
Tires, Wheels
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Tire inflation pressure
A table (see fuel filler flap) lists the tire inflation
pressures specified for Mercedes-Benz recommended
tires as well as for the varying operating conditions.
Important!
Tire pressure changes by approximately 1.5 psi (0.1 bar)
per 18 °F (10 °C) of air temperature change. Keep this in
mind when checking tire pressure inside a garage –
especially in the winter.
Example:
If garage temperature = approximately +68 °F (+20 °C)
and ambient temperature = approximately +32 °F (0 °C)
then the adjusted air pressure = specified air pressure
+3 psi (+0.2 bar). Tire pressures listed for light loads are minimum values
offering high driving comfort. Increased inflation
pressures for heavy loads produce favorable handling
characteristics with lighter loads and are perfectly
permissible. The ride of the vehicle, however, will
become somewhat harder.
Tire temperature and pressure increase with the vehicle
speed. Tire pressure should therefore only be checked
and corrected on cold tires. Correct tire pressure in
warm tires only if pressure has dropped below the
pressure listed in the table and the respective operating
conditions are taken into consideration.
An underinf lated tire due to a slow leak (e.g. due to a
nail in the tire) may cause damage such as tread
separation, bulging etc.. Regular tire pressure checks
(including the spare tire) at intervals of no more than
14 days are therefore essential.

251
Battery
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If a tire constantly loses air, it should be inspected for
damage.
The spare tire should be checked periodically for
condition and inflation. Spare tire will age and become
worn over time even if never used, and thus should be
inspected and replaced when necessary. Battery
Important!
Battery replacement information:
The maintenance-free battery is located in the engine
compartment.
The service life of the battery is dependent on its
condition of charge. The battery should always be kept
sufficiently charged, in order to last an optimum length
of time.
Wa r n i n g !
Do not overinflate tires. Overinflating tires can
result in sudden deflation (blowout) because they
are more likely to become punctured or damaged
by road debris, potholes etc.. Follow recommended
inflation pressures.Do not overload the tires by exceeding the specified
vehicle capacity weight (as indicated by the label
on the driver’s door latch post). Overloading the
tires can overheat them, possibly causing a
blowout.
Wa r n i n g !
Failure to follow these instructions can result 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..

278
Cleaning and care of the vehicle
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Cleaning and care of the vehicle
In operation, your vehicle is subjected to varying
external inf luences which, if gone unchecked, can
attack the paintwork as well as the underbody and
cause lasting damage.
Such damage is caused not only by extreme and varying
climatic conditions, but also by air polution, road salt,
tar, gravel and stone chipping. Grease and oil, fuel,
coolant, brake fluid, bird droppings, insects, tree resins
etc. should be removed immediately to avoid paint
damage. Frequent washing reduces and / or eliminates
the aggressiveness and potency of the above adverse
influences. More frequent washings are necessary to deal with
unfavorable conditions; for example, near the ocean, in
industrial areas (smoke, exhaust emissions), or during
winter operation.
You should check your vehicle from time to time for
stone chipping or other damage. Any damage should be
repaired as soon as possible to prevent the start of
corrosion.
In doing so, do not neglect the underside of the vehicle.
A prerequisite for a thorough check is a washing of the
underbody followed by a thorough inspection. Damaged
areas need to be reundercoated.
Your vehicle has been treated at the factory with a wax-
base ru stproof ing in th e body cavities w hich will la st for
the lifetime of the vehicle. Post-production treatment is
neither necessary nor recommended by Mercedes-Benz
because of the possibility of incompatibility between
materials used in the production process and others
applied later.
We have selected car-care products and compiled
recommendations which are specially matched to our
vehicles and which always reflect the latest technology.
You can obtain Mercedes-Benz approved car-care
products at your authorized Mercedes-Benz Light Truck
Center.
Wa r n i n g !
Many cleaning products can be hazardous. Some
are poisonous, others are flammable. Always follow
the instructions on the particular container.
Always open your vehicle’s doors or windows when
cleaning the inside.Never use fluids or solvents that are not designed
for cleaning your vehicle.