1990 BMW 3 SERIES check engine

expel the air from the master cylinder. A large
Phillips screwdriver can be used to push on
the piston assembly.
11To prevent air from being drawn back into
the master cylinder, the plug must be refitted
and tightened down before releasing the
pressure on the piston assembly.
12Repeat the procedure until brake fluid free
of air bubbles is expelled from the brake line
outlet hole. Repeat the procedure with the
other outlet hole and plug. Be sure to keep the
master cylinder reservoir filled with brake
fluid, to prevent the introduction of air into the
system.
13High pressure is not involved in the bench
bleeding procedure, so the plugs described
above need not be refitted each time the
piston is released, if wished. Instead, before
releasing the piston, simply put your finger
tightly over the hole to keep air from being
drawn back into the master cylinder. Wait
several seconds for brake fluid to be drawn
from the reservoir into the piston bore, then
depress the piston again, removing your
finger as brake fluid is expelled. Be sure to put
your finger back over the hole each time
before releasing the piston, and when the
bleeding procedure is complete for that outlet,
refit the plug and tighten it up before going on
to the other port.
Refitting
14Refit the master cylinder (together with a
new O-ring) over the studs on the brake servo,
and tighten the mounting nuts only finger-tight
at this time.
15Thread the brake line fittings into the
master cylinder. Since the master cylinder is
still a bit loose, it can be moved slightly in
order for the fittings to thread in easily. Do not
strip the threads as the fittings are tightened.
16Tighten the brake fittings securely, and
the mounting nuts to the torque listed in this
Chapter’s Specifications.
17Fill the master cylinder reservoir with fluid,
then bleed the master cylinder (only if the
cylinder has not already been bled) and the
brake system as described in Section 16.
18To bleed the cylinder on the vehicle, have
an assistant pump the brake pedal severaltimes and then hold the pedal to the floor.
Loosen the fitting nut to allow air and fluid to
escape, then tighten the nut. Repeat this
procedure on both fittings until the fluid is
clear of air bubbles. Test the operation of the
brake system carefully before returning the
vehicle to normal service.
8 Brake vacuum servo-
check, removal and refitting
3
Operating check
1Depress the brake pedal several times with
the engine off, until there is no change in the
pedal travel.
2Depress and hold the pedal, then start the
engine. If the pedal goes down slightly,
operation is normal.
Airtightness check
3Start the engine, and turn it off after one or
two minutes. Depress the brake pedal several
times slowly. If the pedal goes down further
the first time but gradually rises after the
second or third depression, the servo is
airtight.
4Depress the brake pedal while the engine is
running, then stop the engine with the pedal
depressed. If there is no change in the pedal
travel after holding the pedal for 30 seconds,
the servo is airtight.
Removal and refitting
5Dismantling the vacuum servo requires
special tools, and cannot be performed by the
home mechanic. If a problem develops, it is
recommended that a new unit be fitted.
6Remove the master cylinder as described in
Section 7.
7Disconnect the vacuum hose from the
brake servo.
8Working in the passenger compartment,
remove the glovebox and lower left-hand trim
panels.
9Remove the clip and clevis pin to
disconnect the pushrod from the cross-shaft
lever (right-hand-drive models) or brake pedal(left-hand-drive models) (see illustration). On
left-hand-drive models, also disconnect the
brake pedal return spring.
10Remove the four mounting nuts (see
illustration)and withdraw the servo unit from
the engine compartment.
11Inspect the small foam filter (see
illustration)inside the rubber boot on the
pushrod. If the filter is clogged, it may affect
the servo’s performance. To clean the filter,
wash it in a mild soapy solution. If it’s still
dirty, renew it.
12Refitting is the reverse of the removal
procedure. Tighten the brake servo mounting
nuts to the torque listed in this Chapter’s
Specifications. Before you slide the boot into
place over the servo pushrod air filter, make
sure the notches in the filter offset the notches
in the damper by 180 degrees.
13On 3-Series models, adjust the basic
setting of the pushrod’s threaded clevis until
the dimension is correct (see illustration).
When the basic setting is correct, tighten the
locknut, then adjust the brake pedal travel and
9•10 Braking system
8.13 On 3-Series models, adjust
dimension A (the distance between the
middle of the brake lever and the
bulkhead/”firewall”) by loosening the
locknut (1) at the pushrod clevis (2) and
turning the threaded part of the pushrod
until dimension A matches the dimension
listed in this Chapter’s Specifications.
When the basic setting is correct, tighten
the locknut, then adjust the brake pedal
height and the stop-light switch
8.11 An exploded view of a typical servo
pushrod assembly
1 Boot 2 Holder 3 Damper 4 Air filter8.10 Remove the four mounting nuts
(arrows) and withdraw the servo unit from
the engine compartment
(left-hand-drive model shown)
8.9 Disconnect the brake pedal return
spring, then remove the clip and clevis pin
(arrows) to disconnect the pushrod from
the brake pedal (left-hand-drive models)

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.

2 Front anti-roll bar-
removal and refitting
2
Removal
1Raise the front of the vehicle, and support it
securely on axle stands.
2If you’re removing or renewing the anti-roll
bar itself, or disconnecting the bar to renew
the strut assembly on a 3-Series model,
disconnect it from the anti-roll bar links (see
illustrations). If you’re renewing the strut
assembly on a 5-Series model, disconnect the
anti-roll bar link from the strut housing.
3On 3-Series models, disconnect the left
control arm rubber bush from the underbody
(see Section 3).
4Remove the bolts from the anti-roll bar
brackets which attach the anti-roll bar to the
subframe (see illustration).
5Remove the anti-roll bar from the vehicle.
Where necessary, separate the anti-roll bar
from the strut bar bracket.
Refitting
6Refitting is the reverse of the removal
procedure. Be sure to tighten all nuts and
bolts to the torques listed in this Chapter’s
Specifications.
3 Control arm (3-Series)-
inspection, removal and
refitting, and bush renewal
3
Inspection
1Raise the front end of the vehicle, and
support it securely on axle stands.
2Grip the top and bottom of each balljoint
with a large pair of water pump (“parrot jaw”)
pliers, and squeeze to check for free play.
Alternatively, insert a lever or large
screwdriver between the control arm and the
subframe or strut housing. If there’s any free
play, renew the control arm (the balljoints
can’t be renewed separately).
3Inspect the rubber bush. If it’s cracked, dry,
torn or otherwise deteriorated, renew it (see
below).
Bush renewal
Note:Rubber bushes should always be
renewed in pairs. Make sure both new bushes
have the same markings (indicating they’re
manufactured by the same firm).
4Remove the two bolts (see illustration)which
attach the bush bracket to the underbody.
5Using a puller, remove the bracket andbush from the end of the control arm. If the
puller slips on the end of the control arm,
centre-punch the control arm to give the
puller bolt a place to seat.
6Note the orientation of the old bush. This is
exactly how the new bush should be
orientated when it’s fitted. Press the old
rubber bush out of the bracket, or have it
pressed out by an engineering works.
7Coat the end of the control arm with BMW’s
special lubricant (Part No. 81 22 9 407 284),
and press the new bush and bracket onto the
arm - or have it pressed on at an engineering
works - all the way to the stop.
Caution: Don’t try to use any
other type of lubricant;
30 minutes after it’s applied, this
lubricant loses its properties and
the bush is permanently located in its
proper position. Make sure the new bush
is pressed on so it’s orientated exactly the
same way as the old bush.
8Refit the bracket bolts and tighten them to
the torque listed in this Chapter’s Specifi-
cations.
9Lower the vehicle, and leave it at rest for at
least 30 minutes (this will give the special
lubricant time to dry).
Control arm removal and
refitting
Note:If either balljoint is worn or damaged,
the only way to renew it is to renew the control
arm. If you’re fitting a new control arm, a new
bush must also be fitted. The old bush can’t
be removed from the old control arm and re-
used in the new control arm.
10Loosen but do not remove the wheel
bolts, raise the front of the vehicle and
support it on axle stands. Remove the wheel
bolts and the front wheel.
11Remove the two bolts which attach the
rubber bush bracket to the underbody (see
illustration 3.4).
12Remove the nut which secures the control
arm balljoint to the subframe, and remove the
balljoint stud from the subframe. Note:It may
be necessary to use a balljoint separator to
separate the balljoint from the subframe (see
illustration), but take care not to damage the
10•4 Suspension and steering systems
3.12 Remove the self-locking nut from the
balljoint stud protruding through the top of
the subframe (not shown in this photo, but
it’s directly above the balljoint) and
separate the balljoint from the subframe.
Try not to damage the dust boot
3.4 Remove the two bolts (arrowed)
securing the bush bracket to the
underbody
2.4 Remove the bolts (arrowed) from the
anti-roll bar brackets to detach the anti-
roll bar from the subframe (3-Series model
shown, 5-series similar)2.2b On 5-Series models, remove the nut
(arrowed) securing the anti-roll bar to the
connecting link (left side shown, right side
similar)2.2a On 3-Series models, remove the nut
(upper arrow) securing the anti-roll bar to
the upper end of the connecting link (left
side shown, right side similar). If a new
control arm is being fitted, remove the
lower nut (lower arrow) and disconnect the
link assembly and bracket from the arm

Bush inspection and renewal
8If the bush is cracked, torn or otherwise
deteriorated, take the arm to a BMW dealer
service department or an engineering works,
and have it pressed out and a new bush
pressed in. Bushes should always be renewed
in pairs (a new bush should be fitted in each
arm, and both bushes should have the same
manufacturer markings). If you’re fitting a new
thrust arm bush, make sure it’s correctly
orientated (see illustration).
Refitting
9Refitting is the reverse of removal. Be sure
to use new self-locking nuts on the balljoint
stud nut and the through-bolt. Don’t forget to
refit the washers on both sides of the through-
bolt. If you’re refitting the control arm, be sure
to use thread-locking compound on the
steering arm mounting bolts. Don’t tighten the
through-bolt to the final torque yet. Note:
Thrust arms are marked “L” for the left side,
and “R” for the right side. Be sure to check the
marking before fitting a new arm.
10Support the control arm with a trolley
jack, and raise it to simulate normal ride
height, then tighten the through-bolt to the
torque listed in this Chapter’s Specifications.Refit the wheel and tighten the wheel bolts to
the torque listed in the Chapter 1 Specifi-
cations.
11Have the front end alignment checked at
a dealer service department or qualified
garage.
5 Front strut assembly-
removal and refitting
3
Removal
Note:Although strut assemblies don’t always
fail or wear out simultaneously, renew both left
and right struts at the same time, to prevent
handling peculiarities or abnormal ride quality.
1Loosen but do not remove the front wheel
bolts.
2Raise the front of the vehicle and support it
on axle stands.
3Remove the front wheel.
4Detach all brake hoses and electrical wires
attached to the strut housing.
5Disconnect the electrical connections for
the ABS system, if applicable.
6If you’re removing the left strut, disconnectthe electrical connector for the brake pad
wear sensor.
7Remove the bolt securing the ABS wheel
sensor, if applicable. Remove the brake disc
(see Chapter 9).
8Remove the brake splash shield (see
illustration).
9On 3-Series models, disconnect the anti-
roll bar from its connecting link (see Sec-
tion 2). On 5-Series models, disconnect the
anti-roll bar link from the strut housing (see
Section 2).
10On 3-Series models, disconnect the
control arm balljoint from the steering knuckle
(see Section 3) and the track rod end from the
steering arm (see Section 17).
11On 5-Series models, disconnect the bolts
that attach the steering arm to the strut
housing (see illustration 4.5).
12Pull out the lower end of the strut housing
far enough to clear the end of the control arm
(3-Series) or the steering arm (5-Series).
13Support the weight of the strut and
remove the three mounting nuts at the top of
the strut, located inside the engine
compartment (see illustration)and remove
the strut.
14Remove the strut assembly. If a new
shock absorber (strut cartridge) is being fitted,
see Section 6.
Refitting
15Refitting is the reverse of removal. On
3-Series models, be sure to use new self-
locking nuts on the control arm balljoint, the
track rod end balljoint and the strut upper
mountings. On 5-Series models, make sure
the tang in the steering arm is mated with the
notch in the strut housing (see illustration).
BMW recommends using a thread-locking
compound on the steering arm mounting
bolts. On all models, tighten the fasteners to
the torques listed in this Chapter’s Specifi-
cations.
16When you’re done, drive the vehicle to a
dealer service department or qualified garage
and have the wheel alignment checked, and if
necessary, adjusted.
10•6 Suspension and steering systems
5.15 On 5-Series models, make sure the
tang in the steering arm is mated with the
notch in the strut housing (arrowed)5.13 Support the weight of the strut and
remove the three mounting nuts (arrowed)
at the top of the strut (5-Series shown,
3-Series similar)5.8 To remove the brake splash shield,
remove these three bolts (arrowed)
4.8 Correct orientation of the bush for the
5-Series thrust arm. The arrow on the
rubber bush is aligned with the mark on
the arm, and the centre of the bush is
concentric with the bore4.7c . . . but you may have to use a
hammer to knock the control arm balljoint
stud loose from the steering arm, because
there’s no room to use a puller. A purpose-
made balljoint separator tool would be
better

6 Strut or shock absorber/coil
spring- renewal
4
Note:This section applies to all front strut
assemblies and, on 5-Series models, the rear
coil-over shock absorber assemblies.
1If the struts, shock absorbers or coil springs
exhibit the telltale signs of wear (leaking fluid,
loss of damping capability, chipped, sagging
or cracked coil springs) explore all options
before beginning any work. Strut or shock
absorber assemblies complete with springs
may be available on an exchange basis, which
eliminates much time and work. Whichever
route you choose to take, check on the cost
and availability of parts before dismantling the
vehicle.
Warning: Dismantling a strut or
coil-over shock absorber
assembly is a potentially
dangerous undertaking, and
utmost attention must be directed to the
job, or serious injury may result. Use only a
high-quality spring compressor, and
carefully follow the manufacturer’s
instructions supplied with the tool. After
removing the coil spring from the strut
assembly, set it aside in a safe, isolated
area.
2Remove the strut or shock absorber
assembly (see Section 5 or 11). Mount the
assembly in a vice. Line the vice jaws with
wood or rags to prevent damage to the unit,
and don’t tighten the vice excessively.
3Following the tool manufacturer’s
instructions, fit the spring compressor (these
can be obtained at most car accessory shops,
or it may be possible to hire one) on the
spring, and compress it sufficiently to relieve
all pressure from the suspension support (see
illustration). This can be verified by wiggling
the spring.
4Prise the protective cap off the damper rod
self-locking nut. Loosen the nut (see
illustration)with a spanner while holding thedamper rod stationary with another spanner
or an Allen key.
5Remove the nut, the strut bearing, the
insulator and the large washer. Check the
bearing for smooth operation. If it doesn’t turn
smoothly, renew it. Check the rubber insulator
for cracking and general deterioration. If there
is any separation of the rubber, renew the
insulator.
6Lift off the spring retainer and the rubber
ring at the top of the spring. Check the rubber
ring for cracking and hardness. Renew it if
necessary.
7Carefully lift the compressed spring from
the assembly and set it in a safe place, such
as a steel cabinet.
Warning: Never place your head
near the end of the spring!
8Slide the protective tube and rubber
bumper off the damper rod. If either is
damaged or worn, renew it.
9If you’re working on a front strut, loosen
and remove the threaded collar (see
illustration)and pull the old strut cartridge
from the strut housing. Pour the old oil from
the strut housing.
10On all struts except gas-charged units, fill
the strut housing with 20 to 25 cc (3-Series),
42 to 47 cc (518i and 520i 5-Series models) or
20 to 25 cc (all other 5-Series models) ofengine oil (the oil helps cool the shock
absorber by transferring heat to the strut
housing). Note:It doesn’t matter what
viscosity or grade of engine oil is used.
11Refitting is otherwise the reverse of
removal. Tighten the threaded collar to the
torque listed in this Chapter’s Specifications.
Make sure you align the end of the coil spring
with the shoulder of the rubber ring and with
the spring retainer (see illustration). Tighten
the damper rod nut to the torque listed in this
Chapter’s Specifications.
12Refit the strut or shock absorber
assembly (see Section 5 or 11).
7 Balljoints- check and renewal
3
Check
Note:On 3-Series models, there are two
balljoints on each control arm - one between
the middle of the arm and the subframe, and
the other between the outer end of the arm
and the steering knuckle. On 5-Series models,
there are balljoints on the outer ends of the
control arm and the thrust arm.
1Raise the vehicle and support it securely on
axle stands.
2Visually inspect the rubber boot between
the balljoint and the subframe or steering
knuckle, etc for cuts, tears or leaking grease.
If you note any of these conditions, renew the
control arm or thrust arm - the balljoints are
not available separately.
3Place a large lever under the balljoint, and
try to push the balljoint up. Next, position the
lever between the arm and the subframe or
between the arm and steering knuckle. If you
can see or feel any movement during either
check, a worn balljoint is indicated.
4Have an assistant grasp the tyre at the top
and bottom, and shake the top of the tyre with
an in-and-out motion. Touch the balljoint stud
nut. If any looseness is felt, suspect a worn
balljoint stud or a widened hole in the
subframe or steering knuckle. If the latter
Suspension and steering systems 10•7
6.4 Prise the protective cap off the
damper rod nut, and remove the large nut
(arrowed) - to prevent the damper rod from
turning, place an Allen key in the end of
the shaft6.3 Following the tool manufacturer’s
instructions, fit the spring compressor to
the spring, and compress it sufficiently to
relieve all pressure from the suspension
support
6.11 Make sure you align the end of the
coil spring with the shoulder of the rubber
ring, and with the spring retainer
6.9 Loosen and remove the threaded
collar, and pull the old strut cartridge from
the strut housing - on all struts except
gas-charged units, pour the old oil from
the strut housing. (Spring should have
been removed first!)
10

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

21 Steering box (5-Series)-
removal and refitting
4
Removal
Note:If you find that the steering box is
defective, it is not recommended that you
overhaul it. Because of the special tools
needed to do the job, it is best to let your
dealer service department overhaul it for you
(otherwise, fit a new unit). Removal and
refitting the steering box is outlined here.
1On 5-Series E28 (“old-shape”) models,
discharge the hydraulic system by depressing
the brake pedal about 20 times.
2Using a large syringe or hand pump, empty
the power steering fluid reservoir (see Chap-
ter 1).
3Raise the front of the vehicle and support it
securely on axle stands.
4Support the front of the engine with a trolley
jack. Place a block of wood between the jack
head and the sump to protect the sump from
damage.
5Remove the pivot bolts from the inner ends
of the front control arms (see Section 4).
6Remove the nuts from the left and right
engine mountings (see Chapter 2).
7Remove the mounting bolts (two on each
side on earlier models, three on each side on
later models) from the subframe crossmember
(see illustration)and remove the subframe.
8Remove the nuts and bolts that secure the
universal joint shaft to the steering box worm
shaft. Slide the universal joint shaft up and off
the worm shaft. Inspect the universal joint
shaft for wear. If it’s stiff or worn, renew it.
9Remove the banjo bolts, and disconnect
the hydraulic pressure line and the return line
from the box (see illustration). Plug the ends
of the lines to prevent fluid loss and
contamination. Discard the sealing washers -
new ones should be used when reassembling.
10Remove the steering box retaining bolts
(see illustrations)and remove the steering
box.
11If it’s necessary to detach the Pitman arm
from the box sector shaft (to have the box
serviced or to switch the arm to a new orrebuilt unit), make a match mark across the
two for correct reassembly. Remove the
Pitman arm retaining nut and washer. Use a
puller to withdraw the arm if necessary.
Refitting
12Refit the Pitman arm by aligning the
match marks made during removal, then
tighten the nut to the torque listed in this
Chapter’s Specifications.
13When fitted the Pitman arm must not have
any measurable endfloat within 100° from the
neutral position. If play exists, have the
following parts checked:
a) Sector shaft and bearings (for wear)
b) Thrust washer and adjuster bolt head (for
wear)
c) Ball nut and worm shaft (for wear)
14Refit the steering box. Align the mark on
the pinion gear shaft with the mark on the
universal joint shaft, and tighten the steering
box bolts to the torque listed in this Chapter’s
Specifications.
15The remainder of refitting is the reverse of
removal. Be sure to use new self-locking nuts
on the universal joint shaft, the centre track
rod, the steering box and the crossmember.
Also, use new sealing washers on the
hydraulic line fittings.
16Refer to Chapter 1 and fill the powersteering reservoir with the recommended
fluid, then bleed the system as described in
Section 23. Check for leakage from the lines
and connections.22 Power steering pump-
removal and refitting
1
Removal
1Raise the vehicle and support it securely on
axle stands. Remove the engine undertray.
2On 5-Series E28 (“old-shape”) models,
discharge the hydraulic system by depressing
the brake pedal about 20 times before
loosening the hydraulic line fittings.
3Disconnect the fluid return hose, and drain
the power steering fluid from the reservoir into
a clean container. Disconnect the pressure
line from the pump.
4If you need to remove the pulley from the
pump, push on the power steering pump
drivebelt by hand to increase the tension, and
unscrew the pulley nuts or bolts.
5Loosen the power steering pump drivebelt
tensioner bolt, and remove the drivebelt (see
Chapter 1).
6Remove the mounting bolts (see
illustrations)and detach the power steering
pump.
Suspension and steering systems 10•15
21.10a This bolt (arrowed) secures the
steering box to the subframe
crossmember. The nut, not visible in this
photo, is accessed through a hole in the
crossmember (engine removed for clarity,
left-hand-drive shown)21.9 Disconnect the power steering
pressure line fitting (right arrow) and the
return line fitting (left arrow). Note that the
return line fitting banjo bolt is larger than
the bolt for the pressure line fitting (left-
hand-drive shown)21.7 Subframe crossmember bolts
(arrowed)
22.6a Typical 3-Series power steering
pump adjusting bolt (arrowed) . . .
21.10b This bolt (arrowed) attaches the
steering box to the body (the nut, not
visible in this photo, is on the front side of
the steering box)
10

Refitting
7Refitting is the reverse of removal. Tighten
the nuts and bolts securely. Adjust the
drivebelt tension (see Chapter 1).
8Top-up the fluid level in the reservoir (see
Chapter 1) and bleed the system (see Sec-
tion 23).
23 Power steering system-
bleeding
1
1To bleed the power steering system, begin
by checking the power steering fluid level and
adding fluid if necessary (see Chapter 1).
2Raise and support the front of the vehicle
on axle stands.
3Turn the steering wheel from lock-to-lock
several times. Recheck the fluid level and top
up if necessary.
4Start the engine and run it at 1000 rpm or
less. Turn the steering wheel from lock-to-
lock again (three or four times) and recheck
the fluid level one more time. Note:On 5-Series E28 (“old-shape”) models, pump the
brake pedal five or six times before turning the
steering wheel. Once the fluid level remains
constant, continue turning the wheel back and
forth until no more bubbles appear in the fluid
in the reservoir.
5Lower the vehicle to the ground. Run the
engine and again turn the wheels from lock-
to-lock several more times. Recheck the fluid
level. Position the wheels straight-ahead.24 Steering wheel-
removal and refitting
1
Warning: If the vehicle is
equipped with an airbag, do not
attempt this procedure. Have it
performed by a dealer service
department or other qualified specialist, as
there is a risk of injury if the airbag is
accidentally triggered.
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.
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.
Removal
1Disconnect the battery negative cable.
2Using a small screwdriver, prise off the
BMW emblem in the centre of the steering
wheel.
3Remove the steering wheel nut, and mark
the relationship of the steering wheel hub to
the shaft (see illustration).
4On all 3-Series models, and on 1986 and
later 5-Series models, turn the ignition key to
the first position to unlock the ignition lock.
5Remove the steering wheel from thesteering shaft. If the wheel is difficult to
remove from the shaft, use a steering wheel
puller to remove it - don’t hammer on the
shaft.
Refitting
6Refitting is the reverse of removal. Be sure
to align the match marks you made on the
steering wheel and the shaft. Tighten the
steering wheel nut to the torque listed in this
Chapter’s Specifications.
25 Wheels and tyres-
general information
1
Note:For more information on care and
maintenance of tyres, refer to Chapter 1.
1All vehicles covered by this manual are
equipped with steel-belted radial tyres as
original equipment. Use of other types or
sizes of tyres may affect the ride and handling
of the vehicle. Don’t mix different types or
sizes of tyres, as the handling and braking
may be seriously affected. It’s recommended
that tyres be renewed in pairs on the same
axle; if only one new tyre is being fitted, be
sure it’s the same size, structure and tread
design as the other.
2Because tyre pressure has a substantial
effect on handling and wear, the pressure on
all tyres should be checked at least once a
month or before any extended trips (see
Chapter 1).
3Wheels must be renewed if they are bent,
heavily dented, leak air, or are otherwise
damaged.
4Tyre and wheel balance is important in the
overall handling, braking and performance of
the vehicle. Unbalanced wheels can adversely
affect handling and ride characteristics, as
well as tyre life. Whenever a new tyre is fitted,
the tyre and wheel should be balanced.
10•16 Suspension and steering systems
24.3 After removing the steering wheel
nut, mark the relationship of the steering
wheel to the steering shaft (arrowed) to
ensure proper alignment during
reassembly
22.6c Typical 5-Series power steering pump mounting bolts
(arrowed)22.6b . . . and mounting nut and bolt (arrowed)