1998 BMW 740I steering

125n
RepairsIndexOverview Controls Car care Technology Data
Antilock Brake System (ABS)The conceptABS enhances active safety by helping
to prevent the wheels from locking dur-
ing brake applications. The reason:
Locked wheels are dangerous. When
the front wheels slide, the driver loses
steering control over the vehicle. Trac-
tion loss at the rear wheels can cause
the rear end to break into an uncon-
trolled skid.
The system can achieve the shortest
braking distances possible under most
conditions (on straights and in curves,
on asphalt, ice, wet road surfaces, etc.).
ABS is designed to meet two essential
requirements during every brake appli-
cation:
>To help provide vehicle stability
>To help maintain steering control and
maneuverability – on all types of road
surfaces (asphalt, concrete, mud, wet
pavement, snow, ice).
Braking with ABSThe system becomes operative once
the vehicle exceeds a speed of approx.
6 mph (10 km/h). The ABS is deactivated
whenever the vehicle's speed drops
back below approx. 4 mph (6 km/h). This
means that the wheels can lock in the fi-
nal phase of a panic stop – a factor of no
significance in actual use.
If you are in a situation which requires
full braking, you will exploit the full bene-
fits of the ABS system if you apply maxi-
mum brake pressure ("panic stop").
Since the vehicle maintains steering re-
sponsiveness, you can avoid possible
obstacles with a minimum of steering ef-
fort, despite the full brake application.
The ABS system closed-loop control cir-
cuit cycles in fractions of a second.
A pulsation at the brake pedal indicates
to the driver that ABS is active, that is,
that the vehicle is within its maximum
braking range. In addition, a pulsation – a
result of the control function cycles – in-
dicates to the driver that vehicle speed
should be reduced to adapt to road sur-
face conditions when there is reduced
traction and grip between tires and road
surface (slippery road surface).
Always depress the brake pedal with
constant pressure. Keep the brake pedal
down. Do not pump the brakes.In driving conditions where there is a
loose upper surface together with a
subsurface which provides better trac-
tion (on gravel or snow, for instance), or
with snow chains, the braking distance
may also be longer than when the
wheels are locked. However, ABS con-
tinues to provide enhanced vehicle sta-
bility and steering response under
these conditions.
Information for your safetyNot even ABS can suspend the laws of
physics. ABS alone cannot prevent ac-
cidents when the brakes are applied
without an adequate safety interval be-
tween vehicles, if the car is driven at an
excessive rate of speed in curves, or if
aquaplaning occurs. Responsibility for
these types of situations remains in the
hands (and at the feet) of the driver. You
should never allow the added safety of
ABS to lull you into a false sense of se-
curity, or mislead you into taking in-
creased risks that could affect your own
safety and that of others.
Do not make any modifications to
the ABS system.
Service procedures on ABS are to be
performed by authorized technicians
only.<

129n
RepairsIndexOverview Controls Car care Technology Data
Winter operationRubber seals and componentsIn order to prevent the weather-strip-
ping from freezing, apply rubber treat-
ment or a silicone spray to the seals on
the doors, hood and luggage compart-
ment lid.
A full range of car care products is
available from your BMW center.< Snow chainsBMW snow chains
* can be fitted on
both summer and winter tires in re-
sponse to severe winter road condi-
tions. Mount them in pairs on the rear
wheels only, and be sure to comply with
the manufacturer's safety instructions.
Do not exceed a maximum speed of
30 mph (50 km/h). In this situation
(snow chains mounted), deactivate the
ASC+T or DSC
*. Refer to page 92.
Starting offWhen starting off in deep snow or when
rocking the car to free it, we recom-
mend that you switch the ASC+T or
DSC
* off. Refer to page 92.
Driving on low-traction road
surfacesUse smooth, gentle pressure to control
the accelerator pedal. Avoid excessive
engine speeds and shift to the next
higher gear at an early point. Adapt
your speed and driving style when ap-
proaching grades. Maintain an ade-
quate distance between yourself and
the car ahead.BrakesWinter road conditions substantially re-
duce the amount of traction available
between the tires and the road surface;
the resulting increases in braking dis-
tance are considerable and should be
continually borne in mind.
ABS is intended to prevent the wheels
from locking during brake applications,
thus helping to maintain vehicle stability
and steering response. If the ABS does not respond in a critical
braking situation and the wheels lock:
Reduce the pressure on the brake
pedal until the wheels just start to roll
again while still maintaining enough
force to continue braking.
Following that, increase pedal pressure
again. Reduce the pressure as the
wheels lock, then reapply pressure, etc.
This type of staggered braking will re-
duce the braking distance, and the ve-
hicle still remains responsive to steer-
ing.
You can then attempt to steer around
hazards after you have reduced pres-
sure on the brake pedal.
Do not shift down on slick road
surfaces. Doing so could cause
the rear wheels to lose traction and
skid, which could result in the loss of
vehicle control.<

130n
Winter operation Power steering Level control system
*
Skid controlRelease the accelerator pedal. Coun-
tersteer carefully and attempt to regain
control of the vehicle.ParkingPlace the selector lever in position P
(Park). Engage the parking brake when
parking on hills and inclined surfaces. In
order to prevent the parking brake lin-
ings from locking in the drum due to
frost or corrosion, dry them by gently
applying the parking brake as the vehi-
cle is coming to a stop. Make sure that
following traffic is not endangered.
The brake lamps do not come on
when the parking brake is ap-
plied.<
High steering effort:
Check the fluid level. Refer to
page 148.
High steering effort during sudden tran-
sitions:
Consult your authorized BMW center
immediately for an inspection.Servotronic special
*
If steering becomes lighter as speed in-
creases:
Malfunction in the electronic control
system. Have your BMW center inspect
this system as soon as possible.
If the power steering fails, in-
creased effort will be required to
steer the vehicle.<
If the message "LEVEL CONTROL IN-
ACTIVE" appears in the Check Control,
there is a malfunction in the level con-
trol system.
Stop and inspect the vehicle. If it is
riding significantly lower in the rear
than in the front, or if it is sitting at an
incline (left rear compared to right rear),
consult the nearest authorized BMW
center. Drive with appropriate caution
in the meantime. The vehicle has re-
duced ground clearance or driving
comfort is noticeably reduced.
Even if the attitude of the vehicle is nor-
mal, you should consult the nearest au-
thorized BMW center if the warning
lamp indicates a system fault.

132n
Tire inflation pressure Tire conditionInformation for your safetyThe factory-approved radial tires are
matched to the car and have been se-
lected to provide optimum safety and
driving comfort on your car.
It is not merely the tire's service life, but
also driving comfort and - above all else
- driving safety which depend on the
condition of the tires and the mainte-
nance of the specified tire pressure.
Incorrect inflation pressure is a frequent
cause of tire damage. They also influ-
ence the roadholding ability of your
BMW.
Check tire inflation pressures – in-
cluding the spare tire – regularly,
at least every two weeks and before be-
ginning a longer trip. If this is not done,
incorrect tire pressures can cause driv-
ing instability and tire damage, ulti-
mately resulting in accidents.<
Tire tread
– tire damage
Inspect your tires frequently for tread
wear, signs of damage and for foreign
objects lodged in the tread. Check the
tread depth.
Tread depth should not be allowed to
go below 0.12 in (3 mm), even though
the legally specified minimum tread
depth is only 0.063 in (1.6 mm). Wear
indicators appear in the tread at 0.063 in
(1.6 mm) to indicate that the legally per-
missible wear limit has been reached.
Below 0.12 in (3 mm) tread depth, there
is an increased risk of aquaplaning,
even at relatively moderate speeds and
with only small amounts of water on the
road.390de331
Do not drive on a deflated (flat)
tire. A flat tire greatly impairs
steering and braking response, and can
lead to complete loss of control over
the vehicle.
Avoid overloading the vehicle so that
the permitted load on the tires is not ex-
ceeded. Overloading can lead to over-
heating and increases the rate at which
damage develops inside the tires.
The ultimate result can assume the form
of a sudden air loss.
Unusual vibrations encountered during
normal vehicle operation can indicate
tire failure or some other vehicle defect,
as can variations in normal vehicle re-
sponse, such as a pronounced ten-
dency to pull to the left or right. Should
this occur, respond by immediately re-
ducing your speed and carefully pro-
ceeding to the nearest BMW center or
professional tire center, or having the
vehicle towed in to have it and its tires
inspected.
Tire damage (up to and including blow-
outs) can endanger the lives of both the
vehicle occupants and other road
users.<

135n
RepairsIndexOverview Controls Car care Technology Data
Winter tires Snow chains
*
Choosing the right tireBMW recommends winter tires (M+S
radial tires) for driving in adverse winter
road conditions. While tires known as
all-season tires (M+S designation) pro-
vide better winter traction than summer
tires with load ratings H, V, W and ZR,
they generally do not achieve the per-
formance of winter tires.
In the interests of sure tracking and safe
steering response at all four wheels,
mount winter tires which are made by
the same manufacturer and which have
the same tread configuration.
Mount only winter tires which have
been approved by BMW. Any BMW
center will be glad to provide you with
information on the best winter tires for
your particular driving conditions.
Do not exceed specified
maximum speeds
Never exceed the maximum
speed for which the tires are
rated.
Unprofessional attempts by laymen to
service tires can lead to damage and
accidents.
Have this work performed by skilled
professionals only. Any BMW center
has the required technical knowledge
and the proper equipment and will be
happy to assist you.<
Tire condition, tire pressureWinter tires display a perceptible loss in
their ability to cope with winter driving
conditions once the tread wears to be-
low 0.16 in (4 mm), and should thus be
replaced.
Comply with the specified tire inflation
pressures - and be sure to have the
wheel and tire assemblies balanced ev-
ery time you change the tires.StorageStore tires in a cool, dry place, away
from light whenever possible. Protect
the tires against contact with oil, grease
and fuel.
Use narrow-link BMW snow chains on
summer or winter tires only in pairs and
only on the rear wheels. Comply with all
manufacturer's safety precautions when
mounting the chains.

139n
RepairsIndexOverview Controls Car care Technology Data
Engine compartment – BMW 740i/L1 Brake fluid reservoir147
2 Power steering fluid reservoir/
Level control system148
3 Auxiliary terminal for jump
starting179
4 Engine oil dipstick143
5 Engine oil filler neck143
6 Coolant expansion tank146
7 Reservoir for headlamp
and windshield washer system142
8 Fuse box176

141n
RepairsIndexOverview Controls Car care Technology Data
Engine compartment – BMW 750iL1 Brake fluid reservoir147
2 Power steering fluid reservoir/
Level control system148
3 Auxiliary terminal for jump
starting179
4 Engine oil filler neck143
5 Coolant expansion tank146
6 Engine oil dipstick143
7 Reservoir for headlamp
and windshield washer system142
8 Fuse box176

143n
RepairsIndexOverview Controls Car care Technology Data
Engine oilChecking the engine oil1 Park the vehicle on a level surface
2 Shut the engine off after it has
reached normal operating tempera-
ture
3 After approx. 5 minutes, pull the dip-
stick out and wipe it off with a clean
lint-free cloth, paper towel, or similar
material
4 Push the dipstick all the way into the
guide tube and pull it out again
5 The oil level should be in between the
two graduations on the dipstick.
As with fuel economy, oil consumption
is directly influenced by your driving
style and vehicle operating conditions.380de076
The oil volume between the two marks
on the dipstick corresponds to approx.
1.1 US quarts (1 liter). Do not fill to be-
yond the upper mark on the dipstick.
Excess oil will damage the engine.460de189
Adding engine oilWait until the level has dropped to just
above the lower mark before adding oil.
However, do not wait until the oil drops
below the lower mark.
BMW engines are designed to op-
erate without oil additives. The
use of additives could lead to damage
in some cases. This is also true for the
automatic transmission, the differential
and the power steering system.< 380de077