1984 BMW 3 SERIES brake light

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

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)

the stop-light switch (see Section 13). Note:
On right-hand-drive models, the brake pedal
in on the right-hand side of the vehicle, and is
connected to the left-hand side by a cross-
shaft. The adjustment is carried out on the
pushrod at the left-hand side, but the
dimension is measured at the pedal on the
right-hand side.
14On 5-Series models, adjust the brake
pedal height and the stop-light switch (see
Section 13).
15Refit the master cylinder (see Section 7)
and attach the vacuum hose.
16Carefully test the operation of the brakes
before returning the vehicle to normal use
9 Hydraulic brake servo-
description, 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.
Description
1On 5-Series E28 (“old-shape”) models, a
hydraulic brake servo system is fitted. The
servo unit, located between the brake pedal
(left-hand-drive) or cross-shaft lever (right-
hand-drive) and the master cylinder, is
operated by hydraulic pressure generated by
the power steering pump. When the engine is
running, the power steering pump supplies
hydraulic pressure to a power flow regulator/
accumulator. The regulator/accumulator
stores and regulates the pressure to the
hydraulic brake servo. When you press the
brake pedal, the pressure in the servo helps
actuate the master cylinder, reducing pedal
effort.
2The hydraulic brake servo cannot be
overhauled; if it fails, a new one must be fitted.
Testing the system requires special tools, so
even fault diagnosis is beyond the scope of
the home mechanic. If the system fails, take it
to a dealer service department or other
qualified garage for repairs.
Removal and refitting
3With the engine off, discharge the hydraulic
accumulator by depressing the brake pedal
20 times or more.
4Remove the master cylinder (see Section 7).
5Clean the area around the return and
supply line fittings, then disconnect them.
Plug the lines, to prevent dirt from entering the
system, and to prevent further fluid loss.
Caution: Even a particle of dirt
can damage the servo, so be
extremely careful to prevent dirt
from entering the system while
the lines are disconnected.
6Working from inside the passenger
compartment, remove the lower left trim
panels above the brake pedal (left-hand-drive
models) or glovebox and trim (right-hand-drive models). On left-hand-drive models, also
disconnect the pedal return spring.
7Prise off the retaining clip, and disconnect
the pushrod from the brake pedal (see
illustration 8.9) or cross-shaft lever.
8Remove the four mounting nuts and
remove the brake servo (see illus-
tration 8.10).
9Refitting is the reverse of removal. Tighten
the hydraulic lines to the torque listed in this
Chapter’s Specifications. Note:Don’t try to
tighten these fittings without a torque wrench.
If they’re loose, they can leak, which can affect
system operation; if they’re tight, they can be
damaged, and they’ll also leak. You’ll need a
crowfoot-type split ring (“brake”) attachment
for your torque wrench to tighten the fittings
properly.
10When you’re done, bleed the brake
hydraulic system (Section 16) and adjust the
brake pedal travel and the stop-light switch
(see Section 13).
10 Handbrake cable(s)- renewal
2
1Peel back the boot at the base of the
handbrake lever, and remove the handbrake
cable adjusting nut (see illustration)which
also secures the cable to the handbrake lever.There are two cables - one for each rear wheel
- and a nut for each cable. On some models, it
may be necessary to remove the centre
console completely for access.
2Raise the vehicle and support it securely on
axle stands.
3Remove the rear brake drum (see Section 6)
or rear brake disc (see Section 5).
4On rear drum models, unhook the
handbrake cable from the lever on the rear
brake shoe (see Section 6). On rear disc
models, remove the handbrake shoes and the
actuator (see Section 12) and unhook the
handbrake cable from the actuator (see
illustrations).
5On rear drum models, pull the cable and
cable conduit (tube) out of the back of the
brake backplate, then detach the cable
conduit from the cable clips on the back of
the trailing arm (it’s easier to pull out the old
cable, and fit the new cable, with the conduit
straight instead of curved). On rear disc
models, it’s unnecessary to detach the cable
conduit from the brake backplate, but it’s a
good idea to detach the conduit from the clips
and guides securing it to the trailing arm, to
take some of the bend out of the conduit.
6Working from the wheel end of the cable
conduit, pull the cable out of the conduit (see
illustration).
7Lubricate the new cable with multi-purpose
grease, then insert it into the cable conduit
Braking system 9•11
10.1 Peel back the handbrake lever boot
and remove the relevant handbrake cable
adjusting nut (both arrowed)
10.6 Pull the cable out of its conduit;
before you refit the new cable, be sure to
lubricate it with multi-purpose grease10.4b . . . then remove the pin securing the
cable to the inner cam, and remove the
inner cam
10.4a To detach the handbrake cable from
the handbrake actuator on models with rear
disc brakes, pull on the outer cam and
disconnect it from the inner cam . . .
9

then back off the adjuster until the shoes
don’t drag (see Section 11). Refit the wheel
bolts, and tighten them to the torque given in
Chapter 1 Specifications.
13 Brake pedal- adjustment
1
Note:You should always adjust brake pedal
height after the master cylinder or brake servo
has been removed or renewed. You should
also adjust the stop-light switch (see Sec-
tion 14).
1Measure the distance between the lower
edge of the brake pedal footpad (ie the edge
furthest from the bulkhead) and the bulkhead
(see illustration), and compare your
measurement with the dimension listed in this
Chapter’s Specifications. If it’s not as listed,
loosen the locknut on the pushrod, and rotatethe pushrod while holding the clevis stationary
until the distance is correct. Note:On right-
hand-drive models, the adjustment is carried
out at the left-hand side of the cross-shaft,
after removing the glovebox, but the
dimension is still measured at the pedal.
14 Stop-light switch-
check and adjustment
1
Note:The stop-light switch should be
checked and, if necessary, adjusted after the
master cylinder or brake servo has been
removed or renewed.
1The stop-light switch is located on a
bracket at the top of the brake pedal. The
switch activates the brake lights whenever the
pedal is depressed.
2With the brake pedal in the rest position,
measure the distance between the switch
contact point on the brake pedal and the
switch housing (see illustration)and
compare your measurement with dimension A
listed in this Chapter’s Specifications.
3If your measurement is outside theindicated dimension, disconnect the wires
from the switch. Loosen the locknuts, screw
the switch in or out until the plunger
dimension is correct, and retighten the
locknuts. Reconnect the wires and check for
correct operation.
15 Brake hoses and lines-
inspection and renewal
4
Warning: Brake fluid is
poisonous. It is also an effective
paint stripper. Refer to the
warning at the start of Section 16.
Inspection
1At the intervals specified in Chapter 1, the
brake hoses and lines should be inspected.
With the vehicle raised and placed securely
on axle stands, the flexible hoses should be
checked for cracks, chafing of the outer
cover, leaks, blisters and other damage.
These are important and vulnerable parts of
the brake system, and inspection should be
thorough. The metal pipes should be checked
for excessive pitting and corrosion. If a hose
or pipe exhibits any of the conditions
described, renew it.
Flexible hose renewal
2Clean all dirt away from the ends of the
hose. Have ready a suitable container to catch
spilled brake fluid when the hose is
disconnected.
3To disconnect the hose at the chassis end,
use a spanner to hold the hex-shaped fitting
on the end of the flexible hose, and loosen the
nut on the metal brake line (see illustration).
If the nut is stuck, soak it with penetrating oil.
After the hose is disconnected from the metal
line, remove the spring clip from the bracket
and detach the hose from the bracket.
4To detach the flexible hose from the caliper,
Braking system 9•13
12.9 When you’re done, the actuator
should be properly seated between the
two shoes as shown (hub removed for
clarity)12.8 Remove the shoes12.7c Remove the shoe hold-down springs
14.2 To adjust the stop-light switch,
loosen the locknuts (1) and screw the
switch (2) in or out until dimension A is
correct
13.1 To adjust the brake pedal height,
loosen the locknut (1) and turn the
pushrod (2) while holding the clevis (3) until
dimension A (the distance between the
lower edge of the brake pedal and the
bulkhead/”firewall”) is within the range
listed in this Chapter’s Specifications (left-
hand-drive shown, right-hand-drive similar)
9
A torch and mirror will prove
helpful for a complete hose
and line check.

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.

13 Headlights- adjustment
2
Note:The headlights must be aimed correctly.
If adjusted incorrectly, they could momentarily
blind the driver of an oncoming vehicle and
cause a serious accident, or seriously reduce
your ability to see the road. The headlights
should be checked for proper aim every
12 months (as is done during the MOT test),
and any time a new headlight is fitted or front-
end body work is performed. It should be
emphasised that the following procedure will
only provide a temporary setting until the
headlights can be adjusted by a properly-
equipped garage.
1Each headlight has two adjusting screws,
one controlling up-and-down movement and
one controlling left-and-right movement (see
illustration). It may be necessary to remove
the grille (see Chapter 11) for access to these
screws.
2There are several methods of adjusting the
headlights. The simplest method requires a
blank wall (or garage door) 25 feet in front of
the vehicle, and a level floor.
3Position masking tape vertically on the wall,
to mark the vehicle centreline and the
centreline of both headlights. Note:It may be
easier to position the tape on the wall with the
vehicle parked only a few inches away, and
then move the vehicle back the required
distance when all marks have been made.
4Make a horizontal line on the wall to mark
the centreline of all headlights.
5Move the vehicle back so that it is 25 feet
away from the marked wall (keep the front end
of the vehicle square to the wall). Adjustment
should be made with the vehicle sitting level,
the fuel tank half-full, and with no unusually
heavy loads in the vehicle.
6Switch on the dipped beam. The bright
spots on the wall should be two inches below
the horizontal line, and two inches to the left
of the headlight vertical lines. Adjustment is
made by turning the adjusting screw to raise
or lower the beam. The other adjusting screwshould be used in the same manner to move
the beam left or right.
7With main beam on, the bright spots on the
wall should be exactly on the vertical lines,
and just below the horizontal line. Note:It may
not be possible to position the headlight aim
exactly for both main and dipped beams. If a
compromise must be made, keep in mind that
the dipped beam is most used, and will have
the greatest effect on driver safety.
8Have the headlights adjusted by a dealer
service department or qualified garage at the
earliest opportunity.
14 Headlight housing-
removal and refitting
1
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.
Removal
1Disconnect the battery negative cable.2Remove the side grille (see Chapter 11),
then remove the rear cover(s) where
necessary.
3Unplug the headlight (sealed beam-type) or
remove the bulb (halogen bulb-type).
4Remove the screws and detach the housing
(see illustration).
Refitting
5Refitting is the reverse of removal.
15 Bulb renewal
1
1The lenses of many lights are held in place
by screws, which makes it a simple procedure
to gain access to the bulbs.
2On some lights, the lenses are held in place
by clips. The lenses can be removed by using
a small screwdriver to prise them off.
3Several bulbs are mounted in self-earthing
holders, and are removed by pushing in and
turning them anti-clockwise (see illustration).
The bulbs can then be removed (see
illustrations).
4The tail lights on 3-Series models are
accessible after removing the housing, then
removing the bulbs (see illustrations).
5To gain access to the facia lights, the
instrument cluster will have to be removed
first (see illustration).
12•6 Body electrical systems
15.3c . . . then pull the bulb from the
holder15.3b On models with high-mounted
centre brake lights, the self-earthing
holder is accessible from the luggage area
- pull the holder out . . .15.3a The tail light bulbs on later 5-Series
models are in self-earthing holders which
can be simply pulled out of the housing -
the bulb is then removed from the holder
14.4 Remove the screws (arrowed) and
detach the headlight housing13.1 The headlight adjustment screws
(arrowed) are accessible from the back of
the headlight on 3-Series models

12Refitting is a reversal of removal. When
fitting the motor, if necessary plug in the
connector and run the motor briefly until it is
in the “neutral” (wiper parked) position.
17 Heated rear window-
check and repair
2
1The heated rear window consists of a
number of horizontal elements on the glass
surface.
2Small breaks in the element can be repaired
without removing the rear window.
Check
3Switch on the ignition and the heated rear
window.
4Place the positive lead of a voltmeter to the
heater element nearest to the incoming power
source.
5Wrap a piece of aluminium foil around the
negative lead of the voltmeter on the positive
side of the suspected broken element, and
slide it slowly towards the negative side.
Watch the voltmeter needle - when it moves
from zero, you have located the break.
Repair
6Repair the break in the line using a repair kit
recommended specifically for this purpose,
such as BMW repair kit No. 81 22 9 (or
equivalent). Included in this kit is plastic
conductive epoxy. The following paragraphs
give general instructions for this type of repair;
follow the instructions supplied with the repair
kit if they are different.
7Prior to repairing a break, switch off the
circuit and allow it to cool down for a few
minutes.
8Lightly buff the element area with fine steel
wool, then clean it thoroughly.
9Use masking tape to mask off the area of
repair, leaving a slit to which the epoxy can be
applied.
10Mix the epoxy thoroughly, according to
the instructions on the package.
11Apply the epoxy material to the slit in the
masking tape, overlapping the undamaged
area about 20 mm on each end.12Allow the repair to cure for 24 hours
before removing the tape and using the
heated rear window.
18 Supplemental Restraint
System (SRS)- general
information
Later models are equipped with a
Supplemental Restraint System (SRS),
incorporating an airbag. This system is
designed to protect the driver from serious
injury in the event of a head-on or frontal
collision. It consists of an airbag module in the
centre of the steering wheel, two crash
sensors mounted on the front inner wing
panels, and a crash safety switch located
inside the passenger compartment.
The airbag module contains a housing
incorporating the airbag and the inflator units.
The inflator assembly is mounted on the back
of the housing over a hole through which gas
is expelled, inflating the bag almost instanta-
neously when an electrical signal is sent from
the system. This signal is carried by a wire
which is specially wound with several turns,
so the signal will be transmitted regardless of
the steering wheel position.
The SRS system has three sensors: two at
the front, mounted on the inner wing panels
(see illustration), and a safety switch located
inside the passenger compartment. The crash
sensors are basically pressure-sensitive
switches, which complete an electrical circuit
during an impact of sufficient force. The
electrical signal from the crash sensors is sent
to a third sensor, which then completes the
circuit and inflates the airbag.
The module containing the safety switch
monitors the system operation. It checks the
system every time the vehicle is started,
causing the AIRBAG warning light to come on,
then go out if the system is operating
correctly. If there is a fault in the system, the
light will stay on. If the AIRBAG warning light
does stay on, or if it comes on while driving,
take the vehicle to your dealer immediately.
19 Cruise control system-
description and check
1
The cruise control system maintains vehicle
speed using a vacuum-actuated servo motor
located in the engine compartment, which is
connected to the throttle linkage by a cable.
The system consists of the servo motor,
clutch switch, brake switch, control switches,
a relay, and associated vacuum hoses.
Because of the complexity of the cruise
control system, repair should be left to a
dealer service department. However, it is
possible for the home mechanic to make
simple checks of the wiring and vacuum
connections for minor faults which can be
easily repaired. These include:
a) Inspect the cruise control actuating switches
for broken wires and loose connections.
b) Check the cruise control fuse.
c) The cruise control system is operated by
vacuum, so it’s critical that all vacuum
switches, hoses and connections are
secure. Check the hoses in the engine
compartment for loose connections,
cracks, or obvious vacuum leaks.
20 Central locking system-
description and check
2
The central door locking system operates
the door lock actuators mounted in each
door. The system consists of the switches,
actuators and associated wiring. Diagnosis is
limited to simple checks of the wiring
connections and actuators for minor faults
which can be easily repaired. These include:
a) Check the system fuse and/or circuit
breaker (where applicable).
b) Check the switch wires for damage and
loose connections. Check the switches
for continuity.
c) Remove the door trim panel(s), and check
the actuator wiring connections to see if
they’re loose or damaged. Inspect the
actuator rods to make sure they aren’t
12•8 Body electrical systems
18.3 The SRS system crash sensors
(arrowed) are located in the engine
compartment - check the wiring regularly
for damage16.11b Tailgate wiper motor (5-Series)16.11c Wiper blade and pivot mechanism
on the rear window (5-Series)

REF•1
REF
MOT Test Checks
This is a guide to getting your vehicle through the MOT test.
Obviously it will not be possible to examine the vehicle to the same
standard as the professional MOT tester. However, working through
the following checks will enable you to identify any problem areas
before submitting the vehicle for the test.
Where a testable component is in borderline condition, the tester
has discretion in deciding whether to pass or fail it. The basis of such
discretion is whether the tester would be happy for a close relative or
friend to use the vehicle with the component in that condition. If the
vehicle presented is clean and evidently well cared for, the tester may
be more inclined to pass a borderline component than if the vehicle is
scruffy and apparently neglected.
It has only been possible to summarise the test requirements here,
based on the regulations in force at the time of printing. Test standards
are becoming increasingly stringent, although there are some
exemptions for older vehicles. For full details obtain a copy of the Haynes
publication Pass the MOT! (available from stockists of Haynes manuals).
An assistant will be needed to help carry out some of these checks.
The checks have been sub-divided into four categories, as follows:
HandbrakeMTest the operation of the handbrake.
Excessive travel (too many clicks) indicates
incorrect brake or cable adjustment.
MCheck that the handbrake cannot be
released by tapping the lever sideways. Check
the security of the lever mountings.
Footbrake
MDepress the brake pedal and check that it
does not creep down to the floor, indicating a
master cylinder fault. Release the pedal, wait
a few seconds, then depress it again. If the
pedal travels nearly to the floor before firm
resistance is felt, brake adjustment or repair is
necessary. If the pedal feels spongy, there is
air in the hydraulic system which must be
removed by bleeding.MCheck that the brake pedal is secure and in
good condition. Check also for signs of fluid
leaks on the pedal, floor or carpets, which
would indicate failed seals in the brake master
cylinder.
MCheck the servo unit (when applicable) by
operating the brake pedal several times, then
keeping the pedal depressed and starting the
engine. As the engine starts, the pedal will
move down slightly. If not, the vacuum hose or
the servo itself may be faulty.
Steering wheel and column
MExamine the steering wheel for fractures or
looseness of the hub, spokes or rim.
MMove the steering wheel from side to side
and then up and down. Check that the
steering wheel is not loose on the column,
indicating wear or a loose retaining nut.
Continue moving the steering wheel as before,
but also turn it slightly from left to right.
MCheck that the steering wheel is not loose
on the column, and that there is no abnormalmovement of the steering wheel, indicating
wear in the column support bearings or
couplings.
Windscreen and mirrors
MThe windscreen must be free of cracks or
other significant damage within the driver’s
field of view. (Small stone chips are
acceptable.) Rear view mirrors must be
secure, intact, and capable of being adjusted.
1Checks carried out
FROM THE DRIVER’S SEAT
1Checks carried out
FROM THE DRIVER’S
SEAT2Checks carried out
WITH THE VEHICLE
ON THE GROUND3Checks carried out
WITH THE VEHICLE
RAISED AND THE
WHEELS FREE TO
TURN4Checks carried out on
YOUR VEHICLE’S
EXHAUST EMISSION
SYSTEM