1990 BMW 5 SERIES ESP

Check
12Warm up the engine, and let it run at idle.
Disconnect the oxygen sensor electrical
connector, and connect the positive probe of
a voltmeter to the oxygen sensor output
connector terminal (refer to the following
table) and the negative probe to earth (see
illustrations).
Note:Most oxygen sensor electrical
connectors are located at the rear of the
engine, near the bulkhead. Look for a large
rubber boot attached to a thick wire harness.
On early 535i models, the connector for the
oxygen sensor heater circuit is under the
vehicle. Look for a small protective cover.
These models should have the updated
oxygen sensor fitted, to make access similar
to other models. Consult your dealer service
department for additional information.
13Increase and then decrease the engine
speed, and monitor the voltage.
14When the speed is increased, the voltage
should increase to 0.5 to 1.0 volts. When the
speed is decreased, the voltage should fall to
about 0 to 0.4 volts.
15Also where applicable, inspect the oxygen
sensor heater (models with multi-wire
sensors). With the ignition on, disconnect the
oxygen sensor electrical connector, and
connect a voltmeter across the terminals
designated in the chart (see below). There
should be battery voltage (approximately
12 volts).
16If the reading is not correct, check the
oxygen sensor heater relay (see Chapter 12).
If the information is not available, check the
owner’s handbook for the exact location of
the oxygen sensor heater relay. The relay
should receive battery voltage.
17If the oxygen sensor fails any of these
tests, renew it.
Renewal
Note: Because it is fitted in the exhaust
manifold, converter or pipe, which contracts
when cool, the oxygen sensor may be very
difficult to loosen when the engine is cold.
Rather than risk damage to the sensor(assuming you are planning to re-use it in
another manifold or pipe), start and run the
engine for a minute or two, then switch it off.
Be careful not to burn yourself during the
following procedure.
18Disconnect the battery negative cable.
Caution: If the radio in your
vehicle is equipped with an anti-
theft system, make sure you
have the correct activation code
before disconnecting the battery. Refer to
the information on page 0-7 at the front of
this manual before detaching the cable.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
19Raise and support the vehicle.
20Disconnect the electrical connector from
the sensor.
21Carefully unscrew the sensor.
Caution: Excessive force may
damage the threads.
22A high-temperature anti-seize compound
must be used on the threads of the sensor, to
facilitate future removal. The threads of new
sensors will already be coated with this
compound, but if an old sensor is removed
and refitted, recoat the threads.23Refit the sensor and tighten it securely.
24Reconnect the electrical connector of the
pigtail lead to the main engine wiring harness.
25Lower the vehicle, and reconnect the
battery.
Oxygen Sensor Heated power
sensor type output signal supply (12V)
Unheated
(single-wire) black wire (+) Not applicable
Heated terminal 1 (+) terminals
(three-wire) 3 (+) and 2 (-)
Heated terminal 2 (+) terminals
(four-wire) 4 (+) and 3 (-)
Throttle Position Sensor (TPS)
General description
26The Throttle Position Sensor (TPS) is
located on the end of the throttle shaft on the
throttle body. By monitoring the output
voltage from the TPS, the ECU can determine
fuel delivery based on throttle valve angle
(driver demand). In this system, the TPS acts
as a switch rather than a potentiometer. One
set of throttle valve switch contacts is closed
(continuity) only at idle. A second set of
contacts closes as the engine approaches
full-throttle. Both sets of contacts are open
(no continuity) between these positions. A
broken or loose TPS can cause intermittent
bursts of fuel from the injector and an
unstable idle, because the ECU thinks the
throttle is moving.
27All models (except for early 535i models
with automatic transmission) combine the idle
and full-throttle switch; a separate idle
position switch indicates the closed-throttle
position, while the TPS is used for the full-
throttle position. On 535i models with
automatic transmission, the TPS is connected
directly to the automatic transmission control
unit. With the throttle fully open, the
transmission control unit sends the full-
throttle signal to the Motronic control unit.
All models except early 535i with
automatic transmission
Check
28Remove the electrical connector from the
TPS, and connect an ohmmeter to terminals 2
and 18 (see illustrations). Open the throttle
Engine management and emission control systems 6•3
4.12b These oxygen sensor terminal
designations are for the harness side only.
Use the corresponding terminals on the
sensor side for the testing procedures
(there are three different four-wire oxygen
sensor connectors available - don’t get
them mixed up)4.12a The oxygen sensor, once it is
warmed up (320º C), puts out a very small
voltage signal. To verify it is working,
check for voltage with a digital voltmeter
(the voltage signals usually range from
0.1 to 1.0 volt)
4.28b First check for continuity between
terminals 2 and 18 with the throttle closed
(later Motronic system shown) . . .4.28a The TPS on L-Jetronic systems is
located under the intake manifold
(terminals arrowed)
6

4Unhook and remove the lower return spring
(see illustrations).
5Unhook and remove the upper return spring
(see illustrations).
6Remove the front and rear brake shoe hold-
down springs (see illustrations).
7Remove the front shoe (see illustration).
8Remove the adjuster assembly (see
illustration). Clean the adjuster and make
sure that the adjuster wheel moves freely on
the threads. It is recommended that the
thermo-clip (the spring clip next to theadjuster wheel) be renewed whenever new
shoes are fitted. Turn the adjuster wheel so
that the assembly is at its shortest position
ready for refitting.
9Disconnect the handbrake cable from the
handbrake lever, and remove the rear shoe
(see illustration).
10Refitting is basically the reverse of
removal, but note the following points.
11Apply a smear of high-temperature brake
grease to the backing plate (see illustration).
Be careful not to get grease onto the
9•8 Braking system
6.11 Before you fit the new shoes, apply
some high-temperature brake grease to
the friction surfaces where the inner edge
of the shoe slides on the brake backing
plate - when you refit the automatic
adjuster mechanism, make sure each end
engages properly with its respective notch
in the brake shoe6.9 To disconnect the handbrake cable
from the handbrake lever, pull on the plug
at the end of the cable, and detach the
cable from the bracket on the upper end of
the lever (diagonal cutting pliers are being
used here because they grip the cable
well, but care must be taken not to nick
the cable)
6.8 Remove the automatic adjuster
assembly
6.7 Remove the front shoe, automatic
adjuster lever and spring as an assembly,
then remove the lever and spring, and set
them aside for attachment to the new shoe
6.6b . . . and the rear shoe hold-
down spring6.6a Remove the front shoe hold-
down spring . . .6.5b . . . then unhook it from the rear shoe
and remove it
6.5a Unhook the upper return spring from
the front shoe . . .6.4b . . . then unhook it from the rear shoe
and remove it6.4a Unhook the lower return spring from
the front shoe . . .

friction surfaces of the brake shoes or
drums.
12Make sure the adjuster assembly is
properly engaged with its respective notch in
the handbrake lever.
13When refitting the automatic adjustment
mechanism, fit the lever on the shoe first (see
illustration), then hook the lower end of the
spring onto the lever and the upper end into
its hole in the front shoe (see illustration).
14When you’re done, the brake assembly
should look like this (see illustration). Now
proceed to the other brake.
15When you’re done with both brakes, refit
the brake drums.
16If the wheel cylinder was renewed (see
Note 2), bleed the hydraulic system as
described in Section 16.
17Depress the brake pedal repeatedly to
actuate the self-adjusting mechanism. A
clicking sound will be heard from the brake
drums as the adjusters take up the slack.
18Check the handbrake adjustment (Sec-
tion 11).
19Refit the wheels and bolts. Lower the
vehicle to the ground, and tighten the wheel
bolts to the torque listed in the Chapter 1
Specifications. Check the operation of the
brakes carefully before driving the vehicle in
traffic.
7 Master cylinder-
removal and refitting
3
Warning: Brake fluid is
poisonous. It is also an effective
paint stripper. Refer to the
warning at the start of Section 16.
Note: Although master cylinder parts and
overhaul kits are available for most models, we
recommend fitting a new or overhauled
master cylinder complete. It will take you more
time to overhaul the master cylinder than to
renew it, and you can’t even determine
whether the master cylinder is in good enough
condition to overhaul it until you have
dismantled it. You may very well find that itcan’t be overhauled because of its internal
condition.
Removal
1The master cylinder is connected to the
brake vacuum servo, and both are attached to
the bulkhead, located on the left-hand side of
the engine compartment (see illustration).
2Remove as much fluid as you can from the
reservoir with a syringe.
3Place rags under the line fittings, and
prepare caps or plastic bags to cover the
ends of the lines once they are disconnected.
Caution: Brake fluid will damage
paint. Cover all body parts, and
be careful not to spill fluid during
this procedure.
4Loosen the union nuts at the ends of the
brake lines where they enter the master
cylinder. To prevent rounding off the flats on
these nuts, a split ring (“brake”) spanner,
which wraps around the nut, should be used.
5Pull the brake lines away from the master
cylinder slightly, and plug the ends to prevent
dirt contamination and further fluid loss.
6Disconnect any electrical connectors at the
master cylinder, then remove the nutsattaching the master cylinder to the brake
servo. Pull the master cylinder off the studs,
and lift it out of the engine compartment.
Again, be careful not to spill fluid as this is
done. Discard the old O-ring (see illustration)
between the master cylinder and the servo
unit.
Warning: The O-ring should
always be renewed. A faulty O-
ring can cause a vacuum leak,
which can reduce braking performance
and cause an erratic idle.
Bleeding procedure
7Before fitting a new or overhauled master
cylinder, it should be bled on the bench.
Because it will be necessary to apply pressure
to the master cylinder piston and, at the same
time, control flow from the brake line outlets, it
is recommended that the master cylinder be
mounted in a vice. Use a vice with protected
jaws, and don’t clamp the vice too tightly, or
the master cylinder body might crack.
8Insert threaded plugs into the brake line
outlet holes. Tighten them down so that there
will be no air leakage past them, but not so
tight that they cannot be easily loosened.
9Fill the reservoir with brake fluid of the
recommended type (see “Lubricants, fluids
and capacities” in Chapter 1).
10Remove one plug, and push the piston
assembly into the master cylinder bore to
Braking system 9•9
6.14 When you get everything back
together, this is how it
should look! 6.13b . . . then hook the lower end of the
spring onto the lever as shown; stretch the
spring, and hook the upper end into its
hole in the handbrake shoe6.13a Refit the automatic adjuster lever
first - make sure it’s properly engaged with
the notch in the front end of the
adjuster mechanism . . .
7.6 Always renew the O-ring (1) - groove
arrowed - between the master cylinder and
the brake servo
7.1 To remove the master cylinder, unplug
the electrical connector (top arrow),
disconnect the brake fluid hydraulic line
fittings (lower right arrow, other fitting not
visible in this photo) and remove the two
master cylinder mounting nuts (lower left
arrow, other nut not visible in this photo) -
5-Series master cylinder shown, 3-Series
similar
9

simply unscrew it. Plug the open fitting in the
caliper if the hose is removed for any length of
time, to prevent dirt ingress.
5Refitting is the reverse of the removal
procedure. Make sure the brackets are in
good condition and the locknuts are securely
tightened. Renew the spring clips if they don’t
fit tightly.
6Carefully check to make sure the
suspension and steering components do not
make contact with the hoses. Have an
assistant turn the steering wheel from lock-to-
lock during inspection.
7Bleed the brake system as described in
Section 16.
Metal brake line renewal
8When renewing brake lines, use genuine
parts only - preferably from a BMW dealer.
9Genuine BMW brake lines are supplied
straight. You’ll need a pipe-bending tool to
bend them to the proper shape.
10First, remove the line you intend to renew,
lay it on a clean workbench and measure it
carefully. Obtain a new line of the same
length, and bend it to match the pattern of the
old line.
Warning: Do not crimp or
damage the line. No bend should
have a smaller radius than
14 mm. Make sure the protective
coating on the new line is undamaged at
the bends.
11When fitting the new line, make sure it’s
well supported by the brackets, that the
routing matches the original, and that there’s
plenty of clearance between movable
components or those components which will
become hot.
12After refitting, check the master cylinder
fluid level, and add fluid as necessary. Bleed
the brake system as outlined in Section 16,
and test the brakes carefully before driving the
vehicle. Be sure there are no leaks.
16 Brake hydraulic system-
bleeding
3
Warning: Wear eye protection
when bleeding the brake system.
If the fluid comes in contact with
your eyes, immediately rinse
them with water, and seek medical
attention. Most types of brake fluid are
highly flammable, and may ignite if spilled
onto hot engine components, for example.
In this respect, brake fluid should be
treated with as much care as if it were
petrol. When topping-up or renewing the
fluid, always use the recommended type,
and ensure that it comes from a freshly-
opened sealed container. Never re-use old
brake fluid bled from the system, and don’t
top-up with fluid which has been standing
open for a long time, as it is potentially
dangerous to do so.
Note:Bleeding the hydraulic system is
necessary to remove any air which has
entered the system during removal and
refitting of a hose, line, caliper or master
cylinder.
1It will probably be necessary to bleed the
system at all four brakes if air has entered the
system due to low fluid level, or if the brake
lines have been disconnected at the master
cylinder.
2If a brake line was disconnected at only one
wheel, then only that caliper or wheel cylinder
need be bled.
3If a brake line is disconnected at a fitting
located between the master cylinder and any
of the brakes, that part of the system served
by the disconnected line must be bled.
4Bleed the right rear, the left rear, the right
front and the left front brake, in that order,
when the entire system is involved.
5Remove any residual vacuum from the
brake servo by applying the brakes about 30
times with the engine off. This will also relieve
any pressure in the anti-lock brake system
(where applicable).
6Remove the master cylinder reservoir
cover, and fill the reservoir with brake fluid.
Refit the cover. Note:Check the fluid level
often during the bleeding operation, and add
fluid as necessary to prevent the fluid level
from falling low enough to allow air into the
master cylinder.
7Have an assistant on hand, an empty clear
plastic container, and a length of clear plastic
or vinyl tubing to fit over the bleed screws.
Alternatively, a “one-man” bleeding kit can be
used. A “one-man” kit usually contains a tubeor bottle with a one-way valve incorporated -
in this way, the pedal can be pumped as
normal, but air is not drawn back into the
system when the pedal is released. If a one-
man kit is used, follow the instructions
provided with it; similarly with pressure
bleeding kits. In any case, you will also need a
supply of new brake fluid of the
recommended type, and a spanner for the
bleed screw.
8Beginning at the right rear wheel, loosen the
bleed screw slightly, then tighten it to a point
where it is tight but can still be loosened
quickly and easily.
9Place one end of the tubing over the bleed
nipple, and submerge the other end in brake
fluid in the container (see illustration).
10Have the assistant pump the brakes a few
times, then hold the pedal firmly depressed.
Note:If the vehicle is equipped with ABS,
have the assistant pump the pedal at least 12
times.
11While the pedal is held depressed, open
the bleed screw just enough to allow a flow of
fluid to leave the caliper or wheel cylinder.
Your assistant should press the brake pedal
smoothly to the floor, and hold it there. Watch
for air bubbles coming out of the submerged
end of the tube. When the fluid flow slows
after a couple of seconds, close the screw
and have your assistant release the pedal.
12Repeat paragraphs 10 and 11 until no
more air is seen leaving the tube, then tighten
the bleed screw and proceed to the left rear
wheel, the right front wheel and the left front
wheel, in that order, and perform the same
procedure. Be sure to check the fluid in the
master cylinder reservoir frequently.
Warning: Never re-use old brake
fluid. It absorbs moisture from
the atmosphere, which can allow
the fluid to boil and render the
brakes inoperative.
13Refill the master cylinder with fluid at the
end of the operation.
14Check the operation of the brakes. The
pedal should feel solid when depressed, with
no sponginess. If necessary, repeat the entire
process. Do not operate the vehicle if you are
in doubt about the effectiveness of the brake
system.
9•14 Braking system
16.9 Place one end of the tubing over the
bleed screw, and submerge the other end
in brake fluid in the container
15.3 A typical brake line-to-brake hose
connection: To disconnect it, use one
spanner to hold the hex-shaped fitting on
the end of the flexible hose (lower right
arrow) and loosen the threaded fitting on
the metal line with a split ring (“brake”)
spanner (upper right arrow), then remove
the spring clip (left arrow)
Brake fluid is an effective
paint stripper, and will attack
plastics; if any is spilt, wash it
off immediately with copious
amounts of water.

Where power-assistance is fitted, hydraulic
pressure (provided by an engine-driven pump)
delivers power steering fluid to the rack-and-
pinion steering gear or the recirculating-ball
steering box - this enhances steering
response and reduces steering effort.
Aside from maintaining the proper level of
power steering fluid in the system and
checking the tension of the drivebelt (see
Chapter 1, where applicable), the steering
system requires no maintenance. However,
on high-mileage vehicles, the track rod end
balljoints, the universal joints on either end of
the universal joint shaft, and the rubber
coupling between the steering column and the
universal joint shaft will wear, develop
excessive play, and cause the steering to feel
somewhat loose. At this point, you’ll have to
renew these items; they can’t be serviced.
Before you conclude that the steering
system needs work, however, always check
the tyres (see Section 25) and tyre pressures
(see Chapter 1). Also inspect the bearings in
the strut upper mounts (see Section 5), the
front hub bearings (see Section 8) and other
suspension parts, which may also be
contributing to an imprecise steering feel.
17 Track rod ends-
removal and refitting
4
1Loosen but do not remove the wheel bolts,
then raise the front of the vehicle and secure it
on axle stands. Remove the front wheel.
3-Series models
2Loosen the nut on the track rod balljoint
stud, and free the balljoint stud from the
steering arm using a balljoint separator. In the
absence of a separator tool, try giving the
steering arm a few light blows with a hammer
(see illustration). Remove the nut, and
separate the balljoint stud from the steering
arm.3Loosen the clamp bolt that locks the track
rod end to the inner track rod. Measure the
length of the track rod end, or paint an
alignment mark on the threads to ensure the
track rod end is refitted in the same position
(see illustration). Unscrew the track rod end
from the inner track rod.
4Refitting is the reverse of removal. Make
sure the mark you made on the threads of the
track rod end is aligned correctly, if
applicable. If you measured the track rod end,
make sure it is refitted to the same distance.
5Have the toe-in checked and, if necessary,
adjusted at a dealer service department or
qualified garage.
5-Series models
6Measure the length of the track rod and
record your measurement, or paint an
alignment mark on the threads to ensure the
track rod end is refitted in the same position
(see illustration). Loosen the clamp bolt.
7Use a balljoint separator or a puller to
separate the track rod end from the steering
arm (see illustration).
8Unscrew the track rod end.
9Refitting is the reverse of removal. Make
sure you align the paint mark made on the
threads of the track rod end, if applicable. If
you measured the track rod end, make sure it
is refitted to the same distance.
10Have the toe-in checked and, if
necessary, adjusted at a dealer service
department or qualified garage.
18 Steering gear boots
(3-Series)- renewal
4
1Remove the track rod ends (see Sec-
tion 17).
2Cut the boot clamps at both ends of the old
boots, and slide off the boots.
3While the boots are removed, inspect the
seals in the end of the steering gear. If they’releaking, renew the steering gear (see Sec-
tion 19).
4Slide the new boots into place and fit new
boot clamps.
5Refit the track rod ends (see Section 17).
19 Rack-and-pinion steering
gear (3-Series)-
removal and refitting
4
Removal
1Loosen but do not remove the wheel bolts,
raise the vehicle and support it securely on
axle stands. Remove the front wheels.
2Mark the lower universal joint on the
steering shaft and the pinion shaft, to ensure
proper alignment when they’re reassembled.
Remove the nut and bolt that attach the lower
end of the universal joint shaft to the steering
gear pinion shaft. Loosen the bolt and nut at
the upper end of the universal joint shaft. Slide
the universal joint shaft up a little, disengage it
from the pinion shaft, and remove it. Inspect
the universal joints and the rubber coupling
for wear. If any of them are worn or defective,
renew the universal joint shaft.
3On power steering models, using a large
Suspension and steering systems 10•13
17.6 Measure the length of the track rod
and record your measurement, or paint an
alignment mark on the threads to ensure
the track rod end is refitted in the same
position, then loosen the clamp bolt
(arrowed)17.3 Loosen the clamp bolt (arrowed) that
locks the track rod end to the inner track
rod. Paint an alignment mark on the
threads, to ensure the track rod end is
refitted in the same position, and
unscrew the track rod end from the inner
track rod17.2 Loosen the nut on the track rod
balljoint stud. For preference use a
balljoint separator; otherwise, give the
steering arm a few light blows with a
hammer to release the balljoint stud.
Remove the nut, and separate the balljoint
stud from the steering arm
17.7 Using a puller to separate the track
rod end from the steering arm
10

syringe or hand pump, empty the power
steering fluid reservoir.
4On power steering models, remove the
banjo bolts and disconnect the power
steering pressure and return lines from the
steering gear. Place a container under the
lines to catch spilled fluid. Plug the lines to
prevent excessive fluid loss and
contamination. Discard the sealing washers
(new ones should be used when
reassembling).
5Disconnect the track rod ends from the
steering arms (see Section 17).
6Remove the nuts and bolts from the
steering gear mounting brackets (see
illustration). Discard the old nuts.
7Withdraw the assembly from beneath the
vehicle. Take care not to damage the steering
gear boots.
Refitting
8Refitting is the reverse of removal. Make
sure the marks you made on the lower
universal joint and the pinion shaft are aligned
before you tighten the clamping bolts for the
upper and lower universal joints. Use new
self-locking nuts on the steering rackmounting bolts, and new sealing washers on
the hydraulic line fittings. Tighten the
mounting bolts, the track rod end nuts and the
universal joint shaft clamping bolts to the
torque values listed in this Chapter’s Specifi-
cations.
9Lower the vehicle to the ground.
10On power steering models, fill the
reservoir with the recommended fluid (see
Chapter 1) and bleed the power steering
system (see Section 23).
11It’s a good idea to have the front wheel
alignment checked by a dealer service
department or qualified garage.
20 Steering linkage (5-Series)-
inspection, removal and
refitting
4
Inspection
1Raise the vehicle and place it securely on
axle stands.
2Firmly grasp each front tyre at the top and
bottom, then at the front and rear, and check
for play in the steering linkage by rocking the
tyre back and forth. There should be little or
no play in any of the linkage balljoints. Inspect
the Pitman arm, the idler arm, the centre track
rod, the inner track rods, the track rod ends
and the steering arms for any obvious
damage. Try forcing the linkage parts in
opposite directions from one another. There
should be no play between any of them. If any
of the parts are bent or damaged in any way,
or if any of the balljoints are worn, renew the
parts concerned.
Removal
3Before dismantling the steering linkage,
obtain a suitable balljoint separator. A two-jaw
puller or a wedge-type tool will work (although
the wedge-type tends to tear the balljoint
boots). Sometimes, you can also jar a balljoint
taper pin free from its eye by striking opposite
sides of the eye simultaneously with two large
hammers, but the space available to do this is
limited, and the balljoint stud sometimessticks to the eye because of rust and dirt.
There is also a risk of damaging the
component being struck.
4To remove the outer track rods, disconnect
the track rod ends from the steering arms (see
Section 17). Remove the nut that attaches the
balljoint on the inner end of each outer track
rod to the centre track rod (see illustration).
Using a balljoint separator, disconnect the
outer track rods from the centre track rod. If
you’re renewing the balljoint at either end of
the outer track rods, paint or scribe alignment
marks on the threads to mark their respective
positions as a guide to adjustment during
reassembly (see illustration 17.3).
5To remove the centre track rod, remove the
nuts that attach the centre track rod balljoints
to the Pitman arm and the idler arm, and use a
balljoint separator to disconnect the balljoints
from the two arms.
6To remove the Pitman arm, you’ll have to
remove the steering box first (see Section 21).
Look for match marks between the sector
shaft and arm. If there aren’t any, scribe a
mark across the bottom face of both parts.
Remove the Pitman arm pinch-bolt and nut,
then remove the arm with a puller.
7To unbolt the idler arm, first remove the
small cover bolted to the top of the subframe
crossmember. Put a spanner on the bolt, and
remove the nut recessed into the underside of
the subframe crossmember (see illustration).
Check the idler arm rubber bush for wear. If
it’s damaged or worn, renew it.
8Check each balljoint for excessive play or
stiffness, and for split or deteriorated rubber
dust boots. Renew all worn or damaged
balljoints. The inner and outer track rod ends
on the outer track rods can be renewed
individually; if either balljoint on the centre
track rod is damaged or worn, you must
renew the centre track rod.
Refitting
9Refitting is the reverse of the removal
procedure, but observe the following points:
a) Realign the match marks on the Pitman
arm and the steering box sector shaft
when reassembling them.
b) If you’re fitting new inner or outer track
rod ends on the outer track rods, position
them so that the match marks made
during dismantling are aligned, and make
sure they are equally spaced on each
side.
c) Position the track rod end balljoint studs
on the outer track rods at an angle of 90°
to each other.
d) Make sure the left and right outer track
rods are equal in length when they are
fitted.
e) Tighten all retaining bolts to the torque
values listed in this Chapter’s Specifi-
cations.
f) When reassembly of the linkage is
complete, have the front wheel alignment
checked, and if necessary, adjusted.
10•14 Suspension and steering systems
20.7 To unbolt the idler arm from the
subframe crossmember, remove this nut
(arrowed)
20.4 To remove an outer track rod,
remove this nut (arrowed) from the end of
the centre track rod, and use a balljoint
separator to separate the balljoint stud
from the centre track rod (if you’re
renewing the inner track rod end, mark the
threads with paint before loosening the
clamp bolt and nut)
19.6 Rack-and-pinion steering gear
mounting bolts (arrowed) - 3-Series
models - (self-locking nuts not visible in
this photo)

3 Interior trim- maintenance
1
Interior trim panels can be kept clean by
wiping with a damp cloth. If they do become
stained (which can be more apparent on light-
coloured trim), use a little liquid detergent and
a soft nail brush to scour the grime out of the
grain of the material. Do not forget to keep the
headlining clean in the same way. After
cleaning, application of a high-quality rubber
and vinyl protector will help prevent oxidation
and cracks. The protector can also be applied
to weatherstrips, vacuum lines and rubber
hoses, which often fail as a result of chemical
degradation, and to the tyres.
4 Upholstery and carpets-
maintenance
1
Mats and carpets should be brushed or
vacuum-cleaned regularly, to keep them free
of grit. If they are badly stained, remove them
from the vehicle for scrubbing or sponging,
and make quite sure they are dry before
refitting. Seats and interior trim panels can be
kept clean by wiping with a damp cloth. If they
do become stained (which can be more
apparent on light-coloured upholstery), use a
little liquid detergent and a soft nail brush to
scour the grime out of the grain of the
material. Do not forget to keep the headlining
clean in the same way as the upholstery.
When using liquid cleaners inside the vehicle,
do not over-wet the surfaces being cleaned.
Excessive damp could get into the seams and
padded interior, causing stains, offensive
odours or even rot.
5 Bodywork repair-
minor damage
3
Note:For more detailed information about
bodywork repair, Haynes Publishing produce
a book by Lindsay Porter called “The Car
Bodywork Repair Manual”. This incorporates
information on such aspects as rust treatment,
painting and glass-fibre repairs, as well as
details on more ambitious repairs involving
welding and panel beating.
Repairs of minor scratches in
bodywork
If the scratch is very superficial, and does
not penetrate to the metal of the bodywork,
repair is very simple. Lightly rub the area of
the scratch with a paintwork renovator, or a
very fine cutting paste, to remove loose paint
from the scratch, and to clear the surrounding
bodywork of wax polish. Rinse the area with
clean water.
Apply touch-up paint to the scratch using a
fine paint brush; continue to apply fine layers
of paint until the surface of the paint in the
scratch is level with the surrounding
paintwork. Allow the new paint at least two
weeks to harden, then blend it into the
surrounding paintwork by rubbing the scratch
area with a paintwork renovator or a very fine
cutting paste. Finally, apply wax polish.
Where the scratch has penetrated right
through to the metal of the bodywork, causing
the metal to rust, a different repair technique
is required. Remove any loose rust from the
bottom of the scratch with a penknife, then
apply rust-inhibiting paint to prevent the
formation of rust in the future. Using a rubber
or nylon applicator, fill the scratch with
bodystopper paste. If required, this paste can
be mixed with cellulose thinners to provide a
very thin paste which is ideal for filling narrow
scratches. Before the stopper-paste in the
scratch hardens, wrap a piece of smooth
cotton rag around the top of a finger. Dip the
finger in cellulose thinners, and quickly sweep
it across the surface of the stopper-paste in
the scratch; this will ensure that the surface of
the stopper-paste is slightly hollowed. The
scratch can now be painted over as described
earlier in this Section.
Repairs of dents in bodywork
When deep denting of the vehicle’s
bodywork has taken place, the first task is to
pull the dent out, until the affected bodywork
almost attains its original shape. There is little
point in trying to restore the original shape
completely, as the metal in the damaged area
will have stretched on impact, and cannot be
reshaped fully to its original contour. It is
better to bring the level of the dent up to a
point which is about 3 mm below the level of
the surrounding bodywork. In cases where the
dent is very shallow anyway, it is not worth
trying to pull it out at all. If the underside of the
dent is accessible, it can be hammered out
gently from behind, using a mallet with a
wooden or plastic head. Whilst doing this,
hold a suitable block of wood firmly against
the outside of the panel, to absorb the impact
from the hammer blows and thus prevent a
large area of the bodywork from being
“belled-out”.
Should the dent be in a section of the
bodywork which has a double skin, or some
other factor making it inaccessible from
behind, a different technique is called for. Drill
several small holes through the metal insidethe area - particularly in the deeper section.
Then screw long self-tapping screws into the
holes, just sufficiently for them to gain a good
purchase in the metal. Now the dent can be
pulled out by pulling on the protruding heads
of the screws with a pair of pliers.
The next stage of the repair is the removal
of the paint from the damaged area, and from
an inch or so of the surrounding “sound”
bodywork. This is accomplished most easily
by using a wire brush or abrasive pad on a
power drill, although it can be done just as
effectively by hand, using sheets of abrasive
paper. To complete the preparation for filling,
score the surface of the bare metal with a
screwdriver or the tang of a file, or
alternatively, drill small holes in the affected
area. This will provide a really good “key” for
the filler paste.
To complete the repair, see the Section on
filling and respraying.
Repairs of rust holes or gashes
in bodywork
Remove all paint from the affected area,
and from an inch or so of the surrounding
“sound” bodywork, using an abrasive pad or a
wire brush on a power drill. If these are not
available, a few sheets of abrasive paper will
do the job most effectively. With the paint
removed, you will be able to judge the severity
of the corrosion, and therefore decide
whether to renew the whole panel (if this is
possible) or to repair the affected area. New
body panels are not as expensive as most
people think, and it is often quicker and more
satisfactory to fit a new panel than to attempt
to repair large areas of corrosion.
Remove all fittings from the affected area,
except those which will act as a guide to the
original shape of the damaged bodywork (eg
headlight shells etc). Then, using tin snips or a
hacksaw blade, remove all loose metal and
any other metal badly affected by corrosion.
Hammer the edges of the hole inwards, in
order to create a slight depression for the filler
paste.
Wire-brush the affected area to remove the
powdery rust from the
surface of the remaining metal. Paint the
affected area with rust-inhibiting paint, if the
back of the rusted area is accessible, treat
this also.
Before filling can take place, it will be
necessary to block the hole in some way. This
can be achieved by the use of aluminium or
plastic mesh, or aluminium tape.
Aluminium or plastic mesh, or glass-fibre
matting, is probably the best material to use
for a large hole. Cut a piece to the
approximate size and shape of the hole to be
filled, then position it in the hole so that its
edges are below the level of the surrounding
bodywork. It can be retained in position by
several blobs of filler paste around its
periphery.
Aluminium tape should be used for small or
very narrow holes. Pull a piece off the roll, trim
11•2 Bodywork and fittings
If the inside of the vehicle
gets wet accidentally, it is
worthwhile taking some
trouble to dry it out properly,
particularly where carpets are involved.
Do not leave oil or electric heaters
inside the vehicle for this purpose.

it to the approximate size and shape required,
then pull off the backing paper (if used) and
stick the tape over the hole; it can be
overlapped if the thickness of one piece is
insufficient. Burnish down the edges of the
tape with the handle of a screwdriver or
similar, to ensure that the tape is securely
attached to the metal underneath.
Bodywork repairs - filling and
respraying
Before using this Section, see the Sections
on dent, deep scratch, rust holes and gash
repairs.
Many types of bodyfiller are available, but
generally speaking, those proprietary kits
which contain a tin of filler paste and a tube of
resin hardener are best for this type of repair. A
wide, flexible plastic or nylon applicator will be
found invaluable for imparting a smooth and
well-contoured finish to the surface of the filler.
Mix up a little filler on a clean piece of card
or board - measure the hardener carefully
(follow the maker’s instructions on the pack),
otherwise the filler will set too rapidly or too
slowly. Using the applicator, apply the filler
paste to the prepared area; draw the
applicator across the surface of the filler to
achieve the correct contour and to level the
surface. As soon as a contour that
approximates to the correct one is achieved,
stop working the paste - if you carry on too
long, the paste will become sticky and begin
to “pick-up” on the applicator. Continue to
add thin layers of filler paste at 20-minute
intervals, until the level of the filler is just
proud of the surrounding bodywork.
Once the filler has hardened, the excess
can be removed using a metal plane or file.
From then on, progressively-finer grades of
abrasive paper should be used, starting with a
40-grade production paper, and finishing with
a 400-grade wet-and-dry paper. Always wrap
the abrasive paper around a flat rubber, cork,
or wooden block - otherwise the surface of
the filler will not be completely flat. During the
smoothing of the filler surface, the wet-and-
dry paper should be periodically rinsed in
water. This will ensure that a very smooth
finish is imparted to the filler at the final stage.
At this stage, the “dent” should be
surrounded by a ring of bare metal, which in
turn should be encircled by the finely
“feathered” edge of the good paintwork.
Rinse the repair area with clean water, until all
of the dust produced by the rubbing-down
operation has gone.
Spray the whole area with a light coat of
primer - this will show up any imperfections in
the surface of the filler. Repair these
imperfections with fresh filler paste or
bodystopper, and once more smooth the
surface with abrasive paper. Repeat this
spray-and-repair procedure until you are
satisfied that the surface of the filler, and the
feathered edge of the paintwork, are perfect.
Clean the repair area with clean water, and
allow to dry fully.The repair area is now ready for final
spraying. Paint spraying must be carried out
in a warm, dry, windless and dust-free
atmosphere. This condition can be created
artificially if you have access to a large indoor
working area, but if you are forced to work in
the open, you will have to pick your day very
carefully. If you are working indoors, dousing
the floor in the work area with water will help
to settle the dust which would otherwise be in
the atmosphere. If the repair area is confined
to one body panel, mask off the surrounding
panels; this will help to minimise the effects of
a slight mis-match in paint colours. Bodywork
fittings (eg chrome strips, door handles etc)
will also need to be masked off. Use genuine
masking tape, and several thicknesses of
newspaper, for the masking operations.
Before commencing to spray, agitate the
aerosol can thoroughly, then spray a test area
(an old tin, or similar) until the technique is
mastered. Cover the repair area with a thick
coat of primer; the thickness should be built
up using several thin layers of paint, rather
than one thick one. Using 400-grade wet-and-
dry paper, rub down the surface of the primer
until it is really smooth. While doing this, the
work area should be thoroughly doused with
water, and the wet-and-dry paper periodically
rinsed in water. Allow to dry before spraying
on more paint.
Spray on the top coat, again building up the
thickness by using several thin layers of paint.
Start spraying at one edge of the repair area,
and then, using a side-to-side motion, work
until the whole repair area and about 2 inches
of the surrounding original paintwork is
covered. Remove all masking material 10 to
15 minutes after spraying on the final coat of
paint.
Allow the new paint at least two weeks to
harden, then, using a paintwork renovator, or
a very fine cutting paste, blend the edges of
the paint into the existing paintwork. Finally,
apply wax polish.
Plastic components
With the use of more and more plastic body
components by the vehicle manufacturers (eg
bumpers. spoilers, and in some cases major
body panels), rectification of more serious
damage to such items has become a matter
of either entrusting repair work to a specialist
in this field, or renewing complete
components. Repair of such damage by the
DIY owner is not really feasible, owing to the
cost of the equipment and materials required
for effecting such repairs. The basic technique
involves making a groove along the line of the
crack in the plastic, using a rotary burr in a
power drill. The damaged part is then weldedback together, using a hot-air gun to heat up
and fuse a plastic filler rod into the groove.
Any excess plastic is then removed, and the
area rubbed down to a smooth finish. It is
important that a filler rod of the correct plastic
is used, as body components can be made of
a variety of different types (eg polycarbonate,
ABS, polypropylene).
Damage of a less serious nature (abrasions,
minor cracks etc) can be repaired by the DIY
owner using a two-part epoxy filler repair
material. Once mixed in equal proportions,
this is used in similar fashion to the bodywork
filler used on metal panels. The filler is usually
cured in twenty to thirty minutes, ready for
sanding and painting.
If the owner is renewing a complete
component himself, or if he has repaired it
with epoxy filler, he will be left with the
problem of finding a suitable paint for finishing
which is compatible with the type of plastic
used. At one time, the use of a universal paint
was not possible, owing to the complex range
of plastics encountered in body component
applications. Standard paints, generally
speaking, will not bond to plastic or rubber
satisfactorily. However, it is now possible to
obtain a plastic body parts finishing kit which
consists of a pre-primer treatment, a primer
and coloured top coat. Full instructions are
normally supplied with a kit, but basically, the
method of use is to first apply the pre-primer
to the component concerned, and allow it to
dry for up to 30 minutes. Then the primer is
applied, and left to dry for about an hour
before finally applying the special-coloured
top coat. The result is a correctly-coloured
component, where the paint will flex with the
plastic or rubber, a property that standard
paint does not normally possess.
6 Bodywork repair-
major damage
5
1Major damage must be repaired by a
qualified bodywork repair specialist, or
preferably by a BMW dealer. Specialised
equipment is required to do the job properly.
2If the damage is extensive, the bodyshell
must be checked for proper alignment, or the
vehicle’s handling characteristics may be
adversely affected and other components
may wear at an accelerated rate.
3Due to the fact that all of the major body
components (bonnet, wings, etc.) are
separate units, any seriously damaged
components should be replaced with new
ones rather than repaired.
Bodywork and fittings 11•3
11
If bodystopper is used, it can
be mixed with cellulose
thinners to form a really thin
paste which is ideal for filling
small holes
Sometimes bodywork
components can be found in
a scrapyard that specialises
in used vehicle components,
often at a considerable saving over the
cost of new parts.