BMW 745i Sedan 2005 User Manual
Page 125
123
Hydroplaning
When driving on wet or slushy roads,
reduce road speed. If you do not, a
wedge of water can form between tires and
road surface. This phenomenon is referred
to as hydroplaning, and is characterized by
a partial or complete loss of contact
between tires and road surface, ultimately
undermining your ability to steer and brake
the vehicle.
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Driving through water
Only drive through water with a maxi-
mum depth of 1 ft/30 cm, and then
only at walking speed at the most. Other-
wise, the vehicle's engine, the electrical
systems and the transmission may be dam-
aged.
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Safe braking
Your BMW is equipped with ABS as stan-
dard equipment. The best way to brake is
to apply maximum pressure to the brake
pedal during emergency: full brake applica-
tion. Since the vehicle maintains steering
responsiveness, you can nevertheless
avoid possible obstacles with a minimum
of steering effort.
Pulsation at the brake pedal combines with
sounds from the hydraulic circuits to indi-
cate to the driver that ABS is in its active
mode.
Driving in wet conditions
While driving in wet conditions and in heavy
rain, it is a good idea to apply light pressure
to the brake pedal every few miles. Monitor
traffic conditions to ensure that this maneu-
ver does not endanger other road users.
The heat generated in this process helps
dry the pads and rotors to ensure that full
braking efficiency will then be available
when you need it.
Hills
To prevent overheating and reduced
efficiency of the brake system, drive
long or steep downhill gradients in the gear
in which the least braking is required.
Otherwise, even light but consistent pedal
pressure can lead to high temperatures,
brake wear and possibly even brake fail-
ure.
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You can further enhance the engine's brak-
ing effect by selecting a lower gear in the
automatic transmission's manual mode,
downshifting as far as first gear on
extremely steep stretches, refer to
page
. This strategy helps you avoid
placing excessive loads on the brake sys-
tem.
Never allow the vehicle to coast with
the transmission in Neutral – or with
the engine switched off – as there is no
engine braking when the transmission is in
Neutral, and no power-assist for brakes
and steering when the engine is not run-
ning.
Never allow floor mats, carpets or any other
objects to protrude into the area around the
accelerator and brake pedals and obstruct
their movement.
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Corrosion on brake rotors
When the vehicle is driven only occasion-
ally, during extended periods when the
vehicle is not used at all, and in operating
conditions where brake applications are
less frequent, there is an increased ten-
dency for corrosion to form on rotors, while
contaminants accumulate on the brake
pads. This occurs because the minimal
pressure which must be exerted by the
pads during brake applications to clean the
rotors is not reached.
Should corrosion form on the brake rotors,
the brakes will tend to respond with a pul-
sating effect that even extended applica-
tion will fail to cure.
Mobile communications devices in
vehicle
BMW does not recommend using
mobile communications devices, e.g.
portable phones, in the interior of the vehi-
cle without a direct connection to an out-
side antenna. Otherwise the vehicle elec-
tronics and mobile communications device
can affect each other. In addition, it is not
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