brake rotor BMW 750IL SEDAN 1998 Owners Manual

122n
To ensure that your vehicle provides
maximum economy throughout a long
service life, we request that you comply
with the following:
Engine and differentialUp to 1,200 miles (2,000 km):
Drive at varying engine speeds and
road speeds, but do not exceed
4500 rpm and/or 105 mph (170 km/h)
during this initial period. Comply with
the legal speed limit at all times.
Refrain from using full throttle and avoid
pressing the accelerator beyond the
kickdown point.
Once 1,200 miles (2,000 km) have
elapsed, engine speeds and road
speeds can gradually be increased.
You should also comply with these
break-in procedures if the engine or dif-
ferential is replaced later in the course
of the vehicle service life.TiresDue to technical factors associated with
their manufacture, tires do not achieve
their full traction potential until an initial
break-in period has elapsed.
Thus drive with extra care during the
initial 200 miles (300 km).When the vehicle is operated on
wet or slushy roads, a wedge of
water may form between the tire and
the road surface. This phenomenon is
referred to as aquaplaning, or hydro-
planing, and can lead to partial or com-
plete loss of traction, vehicle control
and braking effectiveness. Reduce your
speed on wet roads.<
Brake systemApproximately 300 miles (500 km) must
elapse before the brake pads and rotors
achieve the optimal pad-surface and
wear patterns required for trouble-free
operation and long service life later on.
To break-in the separate parking brake
drums, apply the parking brake lightly
when coasting to a standstill (at a traffic
signal, for instance), provided that traf-
fic conditions allow you to do so.
To avoid corrosion, repeat this proce-
dure from time to time.
The brake lamps do not come on
when the parking brake is applied.
Vacuum for the brake system servo unit
on your BMW is available only when the
engine is running. When you move the
car with the engine shut off – when tow-
ing, for instance – substantially higher
levels of pedal force will be required to
brake the vehicle.<
Break-in procedure

126n
Antilock Brake System (ABS) Disc brakesIn the event of a fault
If the ABS warning lamp in the
instrument cluster comes on, re-
fer to page 21. The brake sys-
tem then reverts to conventional
operation as on vehicles without
ABS. However, have the brake
system checked by your BMW center
as soon as possible. To prevent unde-
tected defects and cumulative faults
from adversely affecting the brake sys-
tem, refer any problems to your autho-
rized BMW center at the earliest oppor-
tunity.
Disc brakes furnish optimum decelera-
tion and braking control and greater
fade resistance under heavy use.
When the vehicle is driven only occa-
sionally, during extended periods when
the vehicle is not used at all, and in op-
erating conditions where brake applica-
tions are less frequent, there is an in-
creased tendency for corrosion of the
rotors and accumulation of contamina-
tion on the brake pads. This occurs be-
cause the minimal pressure which must
be exerted by the pads to clean the ro-
tors by brake applications is not
reached.
If the brake rotors are corroded, they
will tend to respond to braking with a
pulsating effect which even extended
application will fail to cure.
We recommend the use of original
BMW brake pads and compo-
nents, otherwise driving safety can be
impaired.<

127n
RepairsIndexOverview Controls Car care Technology Data
Disc brakesDriving notesWhile driving in wet conditions and in
heavy rain, it is a good idea to apply
light pressure to the brake pedal every
few miles. Watch traffic conditions to
ensure that this maneuver does not en-
danger other road users. The heat gen-
erated in this braking process helps dry
the brake pads and rotors.
Maximum braking force is obtained
while the wheels continue to rotate,
peaking when the wheels remain on the
verge of locking without actually doing
so. ABS maintains this state automati-
cally. If the ABS fails, you should revert
to the staggered braking technique de-
scribed below (refer to page 129).
Extended or steep mountain descents
do not necessarily have to lead to re-
duced braking efficiency; downshift to a
gear in which only minimal periodic
brake applications are required - move
the selector lever to the appropriate
lower range.
You can continue to increase the brak-
ing effect of the engine by selecting a
lower gear - you can select transmis-
sion ranges as low as position 2 for ex-
treme conditions.Should engine braking prove inade-
quate, you should still avoid extended,
continuous braking. Instead of main-
taining low to moderate pressure over
an extended period of time, you should
decelerate the vehicle by applying more
substantial force on the pedal (watch
for following traffic!) and then pausing
before repeating the application. This
staggered braking technique allows the
brakes to cool in the intervals between
active braking phases, preventing over-
heating and ensuring that full braking
capacity remains available at all times.
Do not coast with the transmission
selector lever in neutral. Do not
drive with the engine shut off. The en-
gine provides no braking effect when
the transmission is in neutral, and there
is no power-assist for braking or steer-
ing when the engine is shut off.
Never allow floor mats, carpets or any
other objects to protrude into the area
around the accelerator and brake ped-
als and obstruct their movement.<
Dynamic Brake Control (DBC)
*
If you apply the brakes rapidly, this sys-
tem automatically produces the maxi-
mum braking force boost and thus
helps to achieve the shortest possible
braking distance during "panic stops."
All of the benefits of the ABS system
are exploited under these circum-
stances.
Do not reduce the pressure on the
brake pedal for the duration of the
brake application. When the brake
pedal is released, the DBC is deacti-
vated.
In the event of a malfunction, the
warning lamp comes on with a
yellow light. Conventional brak-
ing efficiency is available with-
out limitations.
Have the system checked and
repaired at your BMW center as soon
as possible.
For "Information for your safety"
covering the ABS system, refer to
page 125. This information also gener-
ally applies for DBC.<

150n
Caring for your carWashing your carYou can have your new BMW washed
in an automatic car wash. Car wash
systems that do not employ brushes are
preferable.
Wipe away tough dirt and loosen and
remove dead insects before washing
the car.
To prevent spots, avoid washing when
the hood is still warm, or immediately
after and during exposure to strong
sunlight.
When using an automatic car wash, be
sure that:
>The car wash system is suited for the
dimensions of your vehicle
>No damage will occur on vehicles
with attached body accessories (such
as spoilers or antennas). If you are
uncertain, consult the manager of the
car wash
>The wheels and tires of your vehicle
cannot be damaged by the convey-
ance devices of the car wash system
>The vehicle is cleaned with minimum
brush pressure, and that ample water
is available for washing and rinsing.Vehicles with rain sensor
*:
Clean the windshield regularly. Wax
from automatic car washes or insects,
for example, can cause malfunctions in
the function of the rain sensor.
Turn the rain sensor off in auto-
matic car washes. If you do not,
damage may occur if the wipers switch
on unintentionally.<
Parts of the car which are inaccessible
to the automatic washer - such as door
sills, door and hood edges, etc. -
should be cleaned by hand.
In the winter months, it is especially im-
portant to ensure that the car is washed
on a regular basis. Large quantities of
dirt and road salt are difficult to remove,
and they also cause damage to the ve-
hicle.
If spray wands or high-pressure
washers are used, be sure to
maintain an adequate distance between
the spray source and the vehicle's sur-
face.
Inadequate distance and excessive
pressure can damage or weaken the
finish, making it more susceptible to
subsequent attack. In addition, mois-
ture could penetrate to vehicle compo-
nents, leading to long-term damage.<
When cleaning the headlamps,
please observe the following:
>Do not clean by wiping with a dry
cloth (scratches). Never use abra-
sives or strong solvents to clean the
covers
>Remove dirt and contamination
(such as insects) by soaking with
BMW Car Shampoo and then rinsing
with plenty of water
>Always use a deicer spray to remove
accumulated ice and snow – never
use a scraper.<
After washing the car, apply the
brakes briefly to dry them. Braking
efficiency might otherwise be reduced
by the moisture, and the brake rotors
could also be corroded.<