1993 BMW M3 air suspension

GENERAL
.......
.
.
.
.
.
.
.
.
.
.......
.
...
.330-1



CV
boot,
replacing
........
.
.
.
.........
.
.330-8

RIDE
HEIGHT
....
.
.
.
.
.
...
.
...
.
.
.
.
.
...
.
330-1



REAR
SUSPENSION
ARMS
.
.
.
.
.
.
.
.
.
..
.
330-9

Trailing
arm,
removing
and
installing
.
.
.
....
330-10

SHOCK
ABSORBERS
AND
SPRINGS
.
.
.
330-2



Trailing
arm
bushing,
replacing
.
...
.
.
.
.
.
..
330-11

Rear
shock
absorber,
removing
and
installing
330-3



Upper
control
arm,
removing
and
installing
.
.330-12

Coil
spring,
removing
and
installing
.
.
.
.
.
.
.
.
330-4



Lower
control
arm,
removing
and
installing
.
.330-12

REAR
WHEEL
BEARINGS
....
.
...
.
.
.
..
330-4

Rear
wheel
bearing,
replacing
.......
.
....
330-5



Final
drive
carrier,
removing
and
installing
.
.330-12

DRIVE
AXLES
..
.
.
.
.
.
.
.
.
.
.............
330-6



TABLE
a
.
Rear
Ride
Height
Specifications
..
.
............
330-1
Drive
axle,
removing
and
installing
.........
330-6

GENERAL

Special
service
tools
are
required
for
some
of
the
work
de-
scribed
in
this
repair
group
.
Read
the
procedures
through
be-
fore
beginning
any
job
.

NOTE
-

A
general
description
of
the
rear
suspension
and
a
troubleshooting
guide
can
be
found
in
300
Suspen-
sion,
Steering
and
Brakes-General
.

RIDE
HEIGHT

Rear
suspension
ride
height
is
controlled
by
the
rear

springs
.
If
the
rear
ride
height
is
not
within
the
specifications

listed,
the
rear
springs
should
be
replaced
.

Ride
height
is
measured
from
the
lower
edge
of
the
wheel

arch
to
the
bottom
edge
of
the
wheel
rim
.
See
Fig
.
1
.

Table
a
lists
rear
suspension
ride
height
specifications
.



ooy

98
These
specifications
apply
to
a
car
in
a
normally
loaded
posi-

tion
.
When
checking
ride
heightor
installing
suspension
com-



Fig
.
1
.



Ride
height
measurement
(A)
is
taken
from
center
of
wheel

ponents,
load
the
caras
follows
:



archto
bottom
of
wheel
rim
.

Normal
loaded
position

"
Each
front
seat
..
...
.
.
.............
68kg
(150
lb)

"
Rear
seat
(center)
..
.
.
.............
68
kg
(150
lb)

"
Trunk
.........
.
.
.
.
.
..............
21kg
(46
lb)

"
Fue¡
tank



.....



.
..



.
.
.
................



.



..
..
.
full

NOTE-

M3
ride
height
is
measured
with
the
car
unladen
.

330
Rear
Suspension

REAR
SUSPENSION



330-1

FINAL
DRIVE
CARRIER
.
.......
.
.
.
.
.
..
330-12

Table
a
.
Rear
RideHeight
Specifications

Wheel
size



318,323,325,



M3
modeis
328
modeis

15
inch
std
.
suspension



518
mm
(20
.39
in)
sport
suspension



~
507
mm
(19
.96
in)

16
inch
std
.
suspension



531
mm
(20
.91
in)
sport
suspension



~
520
mm
(20
.47
in)

Continued

RIDE
HEIGHT

330-2



REAR
SUSPENSION

Table
a
.
Rear
RideHeight
Specifications

Wheel
size



318,323,
325,



M3
modeis
328
modeis

17inch
std
.
suspension



546
mm
(21.69
in)
sport
suspension



~
535
mm
(21.06
in)



1
540
mm
(21
.26
in)

Maximum
variation
between
sides
:
10
mm
(0
.4in)
Maximum
deviation
from
specifications
:
10
mm
(0
.4in)

SHOCK
ABSORBERS
AND
SPRINGS

The
BMW
E36
independent
rear
suspension
is
shown
in

Fig
.
2
.
Refer
tothis
illustration
while
performing
repairs
on

components
covered
in
this
repair
group
.

NOTE-

Shock
absorbers
andlor
springs
shouldalways
be
re-
placed
in
pairs

i

Stabilizer
bar
link

Trailing

arm
-

bushing

Fig
.
2
.



BMW
E36
rear
suspension
.

SHOCK
ABSORBERS
AND
SPRINGS

Lower
control
arm

Trailing
arm

front
bracket

WARNING
-

"
Do
not
reuse
self-locking
nuts
.
They
arede-

signed
to
beused
only
once
and
may
fail
if
re-

used
.
Always
replace
them
with
new
self-locking

nuts
.

"
Personal
injury
may
result
if
procedures
de-
scribed
here
are
undertaken
without
the
proper
service
tools
and
equipment
.
Be
sure
to
have
the
right
tools
onhand
before
beginning
the
job
.

"
Do
not
install
bolts
and
nuts
coated
with
under-
coating
wax,
as
correct
tightening
torque
cannot

be
assured
.
Always
clean
the
threads
with
sol-

vent
before
installation,
or
ínstall
new
parts
.
"
Do
not
attempt
to
weld
or
straighten
any
suspen-
sion
components
.
Replace
damaged
parts
.

330-
4



REAR
SUSPENSION

7
.
Installation
is
reverse
ofremoval,
noting
the
following
:

"
Make
sure
all
threaded
bolts,
nuts
and
makng
surfaces

are
clean
.

"
Instan
shock
absorber
finto
shock
tower
using
a
new

uppermounting
gasket
and
new
self-locking
nuts
.

"
Tighten
lower
boltto
its
final
torque
oncecar
is
on
ground
.

Tightening
Torques

"
Road
wheel
to
hub
.........
100±10
Nm
(74±7
ft-Ib)

"
Shock
absorber
to
trailing
arm

(car
in
normalloaded
position)
......
77
Nm
(57
ft-Ib)

"
Shock
absorber
to
upper
mount
.....
14
Nm
(10
ft-Ib)

"
Shock
absorber
upper
mount
to
body
(M8
self-locking
nuts)
.............
24
Nm
(17
ft-Ib)

Coil
spring,
removing
and
installing

WARNING
-

"
The
coil
spring
is
undercompressive
force
and
ís
extremely
dangerous
until
compression
isre-
moved
.

"
lt
is
recommended
that
a
restraining
chain
be
in-
stalled
between
the
bottomof
the
coil
spring
and
the
upper
control
arm
to
retain
the
spring
in
case
of
accidental
release
.
Personal
injury
can
result
if
the
compressed
coil
spring
is
not
released
slowly
and
carefully
.

"
Make
sure
that
the
car
is
firmly
supported
on
jack
standsdesigned
for
the
purpose
.
Place
the
jack
standsbeneatha
structural
chassis
point
.
Do
not
place
jack
stands
under
suspension
parts
.

1
.
Raise
car
and
remove
rear
wheel
.

2
.
Support
suspension
arm
from
below
using
a
transmis-

sion
jack
orequívalent
.
Tightening
Torques

3
.
Remove
drive
axle
from
final
drive
.
See
Fig
.
6
.
Suspend



"
Drive
axle
to
final
drive
flange

drive
axle
from
chassis
using
stiff
wire
.



M8
Torx
bolt
.
..
...
.
.............
64
Nm
(47
ft-Ib)

M10
Torx
bolt
...................
83
Nm
(62
ft-Ib)

4
.
Disconnect
shock
absorber
from
traíling
arm
.



"
Road
wheel
to
hub
.........
100±10
Nm
(74±7
ft-Ib)

"
Shock
absorber
to
trailing
arm
......
77
Nm
(57
ft-Ib)
5
.
Lower
suspension
slowly
and
carefully
until
the
com-
pressed
coil
spring
is
fully
unloaded
.

CAUTION
-

The
shock
absorber
prevents
the
drive
axle
and
trailíng
arm
from
drooping
too
far,
so
always
sup-port
the
trailing
arm
before
removing
the
shock
.
Damage
to
drive
axle
CV
joints
can
result
.

6
.
Remove
restraining
chain
and
remove
coi¡
spring
.

REAR
WHEEL
BEARINGS

Fig
.
6
.



Driveaxle
to
final
drive
mounting
bolts
(arrows)
.

0012103

7
.
If
spring
is
to
be
reused,
carefully
inspect
it
for
any
sur-

face
damage
or
corrosion
.
Inspect
spring
mounts
for

any
signs
of
damage
.
Replace
any
parts
showing
evi-

dence
of
wear
or
damage
.

8
.
Fit
coil
springtospring
mountsand
insta¡¡
restraíning

chaina

9
.
Slowly
lift
suspensionback
into
position,
making
sure

coil
spring
is
correctly
seated
in
upper
and
lower
coil

spring
mounts
.

10
.
When
suspension
has
been
lifted
sufficiently,
instan

shock
absorber
to
trailing
arm
.
Remove
restraining

chain
.

11
.
The
remainder
of
installation
is
reverse
of
removal
.

REAR
WHEEL
BEARINGS

The
rear
wheel
bearing
is
a
unitized
assembly
and
is
not
re-

pairable
separately
.
See
Fig
.
7
.

Special
press
tools,
to
be
used
with
the
trailing
arm
at-
tached
to
the
car,
are
requiredto
replace
the
wheel
bearings
.
Read
the
procedure
through
before
beginning
thejob
.

330-
8



REAR
SUSPENSION

CV
boot,
replacing

NOTE-

"
The
outer
CV
joint
cannot
be
removed
from
the
axle
shaft
.
In
order
to
replace
the
outer
CV
boot,
it
is
nec-
essary
to
remove
the
inner
joint
and
boot
first
.

"
If
the
CV
joints
are
worn
or
defective,
acomplete
re-

built
axle
shaft
is
available
from
an
authorized
BMW
dealerparts
department
.

1
.
Remove
drive
axle
from
car
as
described
above
.

2
.
Remove
inner
and
outer
CV
boot
clamping
bands
and

cut
old
boots
off
joints
and
shaft
.
Clean
grease
from

joints
.

3
.
Lift
off
dust
cover
from
inner
CV
joint
and
remove
circlip



5
.
Clean
all
old
lubricantoff
shaftsplines
and
inner
joint's

retaining
joint
inner
hub
to
axle
shaft
.
See
Fig
.
14
.



splines
.

DRIVE
AXLES

-0
1
,
1
1,1
1
L
"I
C
OYA

Drive
axle-"
e
:>,



)



0006560

CV
joint

Fig
.
15
.
Support
CV
joint
at
inner
hub
duringpressing
operation
(ar-
rows)
.

NOTE-

To
inspect
a
CV
joint,
clean
away
the
grease
and
look
for
galling,pittihg
and
othersigns
of
wear
or
physical
damage
.
Polished
surfaces
or
visible
ball
tracks
alone

are
not
necessarily
cause
for
replacement
.
Discolora-

tion
due
to
overheating
indicates
lackof
lubrication
.

6
.
Place
new
clamping
bands
and
CV
boots
over
drive
ax-

le
.

NOTE-

When
replacing
CV
joint
boots,
usecomplete
CV
joint

boot
repair
kits
.
A
kit
will
include
a
new
boot,
clamping

bands,
special
lubricant,
and
anew
inner
CV
joint
cir-
clip
.
The
kit
is
available
from
an
authorized
BMW
dealer
parts
department
.

7
.
Apply
Loctite
®
270
or
an
equívalent
heavy-duty
lockíng

compound
to
drive
axlesplines
.
Position
new
CV
joint

on
shaft
so
that
raisedor
taller
side
of
hub
is
facing
shaft
.

WARNING
-

Fig
.
14
.
Dust
cover
shown
removed
from
inner
CV
joint
.
Clean
away



Do
not
let
the
locking
compound
contact
the
balls
in

grease
and
remove
circlip
(arrow)
from
shaft
end
.



the
joint
.
Apply
only
a
thin
coat
to
cover
the
splines
.

4
.
While
supporting
inner
hub,
press
axle
shaft
out
of
joint
.



8
.
While
supporting
axle
shaft,
press
inner
hub
of
CV
joint

See
Fig
.
15
.



onto
shaft
.
Install
new
circlip
.

NOTE-

Do
not
let
the
ball
hub
pivot
more
than
20°
in
the
outer
ring
of
the
joint
.
The
halls
will
fall
out
if
the
hub
ís
pivoted
too
far
.

9
.
Packeach
CV
joint
and
rubber
boot
with
specified



REAR
SUSPENSION
ARMS
amount
of
lubricant
supplied
.
Apply
adhesive
to
large
end
of
boot
and
mount
it
on
joint
.
Secure
boot
with
clamps
.



The
trailing
arms,
control
arms
and
their
mountingbushings
Apply
sealer
to
inner
CV
joint
dust
cover
and
instan
.



control
the
position
of
the
rear
wheels
.
A
damaged
suspen-
sion
arm
or
worn
bushings
will
change
the
rear
wheel
align
NOTE-



ment
and
may
adversely
affect
handling
and
stability
.
"
Before
installing
each
small
boot
clamp
be
sure
to
"burp"
the
boot
by
flexing
the
CV
joint
as
far
overas
it



WARNING
will
go
.
A
small
screw-driver
inserted
between
the



Do
notattempt
to
straighten
a
damaged
suspension
boot
and
the
axle-shaft
will
help
the
process
.



arm
.
Bending
or
heating
may
weaken
the
original
"
BMW
recommends
Bostil101513
or
EppleC4851
ad-



part
.
If
the
suspension
arm
shows
any
signs
of
hesive,
and
Epple®39
or
Curil©T
sealer



damage
or
excessive
corrosion,
it
must
be
re-
placed
.

CV
Joint
Lubricant
Capacity

"
Wheel
hub
end

ex
.
M3
..
..
.
....
.
.............
80
gram
(2.8
oz
.)
M3
..
...
.
..
.................
100
gram
(3
.5
oz
.)

"
Finaldrive
end
.................
85
gram
(3
.0
oz
.)

10
.
Install
drive
axle
as
described
earlier
.

1
.



Final
drive
carrier
2
.



Stabilizer
bar
3
.



Upper
control
arm4
.



Lower
control
arm5
.



Trailing
arm6
.



Trailing
arm
front
bracket

Fig
.
16
.
Rear
trailing
arms,
control
arms
and
final
drive
carrier
.

If
the
rear
brake
cine
is
disconnected
to
remove
a
trailing
arm,
the
complete
braking
system
must
be
bled
as
partof
the
installation
procedure
.

When
performing
repairs
to
rear
suspension
components,
refer
to
Fig
.
16
.

REAR
SUSPENSION



330-
9

0013112

REAR
SUSPENSION
ARMS

GENERAL
......
.
.
.
.
.
.
.
.....
.
.
.
.
.
.
.
.
.
.
331-1



Final
Drive
Oil
Seals



.
.
...
.
.
.
.......
.
.
.
.
.
331-1

Finaldrive
flange
oil
sea¡,
replacing
....
.
.
.
..
331-2

FINAL
DRIVE
SERVICE
.
.....
.
.
.
.
.
.
.
.
.
.
331-1



Finaldrive
inputshaft
oil
seal,
replacing
.
.
.
.
.
331-3

Final
drive
oí¡,
draining
and
filling
.
.
.
.
.
.
.
.
.
.
331-1



Finaldrive
unit,
removíng
and
installing
.
.
.
.
.
.
331-3

GENERAL

This
repa¡r
group
covers
repair
operations
that
do
not
re-

quire
complicated
disassembly
of
the
final
drive
.
Internal
re-

pairs
and
final
drive
disassembly
are
not
covered
in
this

manual
.

FINAL
DRIVE
SERVICE

Al¡
final
drive
work
requires
some
method
of
raising
thecar

and
supporting
it
securely
while
the
work
is
performed
.
Jack

stands
and
a
floor
jack
can
easily
be
used,
but
use
extreme

caution
when
working
beneath
the
car
.
See010
Fundamen-

tais
for
the
Do-It-Yourself
Owner
.

NOTE-

Removal
of
final
drive
carrier
is
covered
in
330
Rear
Suspension
.

Final
drive
oil,
draining
and
filling

1
.
Drive
car
to
warm
final
drive
fluid
.

2
.
Raise
car
and
support
safely
.

WARNING
-

Make
sure
that
thecar
is
firmly
supported
on
jack
standsdesigned
for
the
purpose
.
Place
the
jack
standsbeneatha
structural
chassis
point
.
Do
not
place
jack
stands
under
suspension
parts
.

5
.
Fill
final
drive
with
appropriate
type
and
quantity
of
lu-

bricant
.
Insta¡¡
and
tighten
fill
plug
.

331
Final
Drive

0

Fig
.
1
.



Final
drivedrain
plug
(A)
and
fill
plug
(B)
.

D

NOTE-

The
final
drive
fluid
level
is
correct
when
the
fluid
begins
to
spill
from
the
fill
plug
.

Final
Drive
Oil
Seals

FINAL
DRIVE



331-1

0013113

Final
DriveDrain
and
Fill

"
Oil
specifications

w/o
limited
slip



.
.......
BMW
SAF-XO
Synthetic
Oil

with
limited
slip
.
......
BMW
SAF-XIS
Synthetic
Oil

"
Final
drive
oil
capacity

4-cylinder
.
.
.
...
................
1
.1
liters
(1
.2
qt)

6-cylinder
.
.
.
...
................
1
.7liters(1.8
qt)

3
.
Place
a
drain
pail
below
final
drive
andremove
drain

and
fill
plugfrom
final
drive
.
See
Fig
.
1
.



Low
oil
level
caused
by
faulty
oil
seals
may
be
the
cause
of

noisy
final
drive
operation
or
limited-slip
chatter
.
The
drive

NOTE-



flange
(side)
and
inputshaft
(front)
oil
seals
can
be
replaced

"
Use
a14
mm
alíen
bit
socket
to
remove
the
drain
plug
.



while
the
final
drive
is
installed
.

Alternatively,
cut
approximately
30
mm
(1
.2
in)
from

an
alíen
key
and
usea
box
end
wrenchon
the
key



NOTE-
stub
.
Do
not
mistake
leaking
CV
joints
for
flangeseal
leaks
.

4
.
Install
and
tighten
drain
plug
.



It
may
be
helpful
to
degrease
the
final
drive
to
pinpoint
the
source
of
the
leak
prior
to
replacing
seals
.

FINAL
DRIVE
SERVICE

Brake
rotor,
removing
and
installing
.
.
.
.
.
.
.
.
340-7

MASTER
CYLINDER
............
.
.
.
.
.
.
.340-7

Master
cylinder,
removing
and
installing
.
...
.
340-7

GENERAL



TROUBLESHOOTING

WARNING
-

"
Although
semi-metallic
and
metallic
Brake
friction
materials
in
Brake
pads
or
shoes
no
longer
con-
tain
asbestos,
they
produce
dangerous
dust
.
"
Brake
fluid
is
poisonous,
highly
corrosive
and
dangerous
to
the
environment
Wear
safety
glasses
and
rubber
gloves
when
working
with
Brake
fluid
.
Do
not
siphonBrake
fluid
with
your
mouth
.
Immediately
clean
away
any
fluid
spilled
on
painted
surfaces
and
wash
with
water,
asBrake
fluid
will
remove
paint
.

"
Always
use
new
Brake
fluid
froma
fresh,
un-
opened
container
.
Brake
fluid
will
absorb
mois-
ture
from
the
air
.
This
canlead
to
corrosion
problems
in
the
brakingsystem,
and
will
also
low-
er
the
Brake
fluid's
boiling
point
.
Dispose
of
Brake
fluid
properly
.

"
Do
notreuse
self-locking
nuts,bolts
or
fasteners
.
They
are
designed
to
be
used
only
once
and
may
failif
reused
.
Always
replace
them
with
new
self-
locking
fasteners
.

BMW
E36
models
areequipped
with
vacuum
power-assist-

ed
four-wheel
disc
brakes
with
an
integral
Antilock
Brake
Sys-

tem
(ABS)
.
Single-pistoncalipers
act
on
solid
or
vented
front
rotors
and
solid
rear
rotors
.
A
brake
pad
wear
sensor
for
each

axle
indicates
when
brake
padsneed
replacement
.
The
dual

drum-type
parking
brakesystem
is
integrated
with
the
rear
brake
rotors
.

NOTE-

M3
models
havevented
directional
Brake
rotors
on
the
rearaxle
as
well
ason
the
front
.

340
Brakes

BRAKES
340-1

GENERAL
.
.
.
.
.
.
.........
.
.
.
..........
340-1



BRAKE
BOOSTER
.........
.
.
.
.
.
...
.
.
.
.
340-8

TROUBLESHOOTING
.......
.
......
.
...
340-1



Brake
booster,
removing
and
installing
....
.
.
340-8

PARKING
BRAKE
.
.....
.
...
.
.
.
.....
.
.
.
340-10
BLEEDING
BRAKES
.
.
.
.
.
.
.
.
..........
340-3



Parking
brake,adjusting
.
.
.
.
.
.
.
.
.
.
.....
.
340-10
Pressure
bleeding
brakes



Parking
brake
shoes,
removing
and
installing
.
340-11(except
cars
with
AST)
.
.
.
.
.
.
.
.
.
...
.
.
.
.
.340-3



Parking
Brake
cable,
replacing
.
.
.
.
.
.
.
.
.
.
.
.
340-11

BRAKE
PADS,
CALIPERS,



ANTILOCK
BRAKE
SYSTEM
(ABS)
.
.
.
.340-11
AND
ROTORS
..........
.
.......
.
.
.
.
.
.
.
340-3



ABS
System
Inspection
.
...
.
.......
.
.
.
..
340-12
Brake
pads,
replacing
............
.
.
.
.
.
.
.
340-4
ABS
wheel
speed
sensors,
replacing
.
.
.
.
..
340-12
Brake
caliper,
removing
and
installing
.
..
..
.
340-6

TABLES

a
.
Brake
System
Troubleshooting
.....
...
.
.
.....
.340-2
b
.
Brake
Rotor
Reconditioning
Specifications
.
.....
.340-7

Brakeperformance
is
mainly
affected
by
three
things
:
the
leve¡
and
condition
of
the
brake
fluid,
the
system's
abilíty
to
create
and
maintain
hydraulic
pressure,
and
the
condition
of
the
friction
components
.

Air
in
the
Brake
fluid
will
make
the
Brake
pedal
feel
spongy

during
braking
or
will
increase
the
Brake
pedalforce
required

to
stop
.
Fluid
contaminated
by
moisture
or
dirt
can
corrode
the

system
.
Inspect
the
Brake
fluid
inside
the
reservoir
.
Ifit
is
dirty
or
murky,
or
is
over
a
year
old,
the
fluid
should
be
replaced
.

Visually
check
the
hydraulic
system
startingat
the
master

cylinder
.
To
check
the
function
of
the
master
cylinder
hold
the

brake
pedal
down
hard
with
the
engine
running
.
The
pedal

should
feelsolid
and
stay
solid
.
If
the
pedal
slowly
falls
to
the

floor,
either
the
master
cylinder
is
leaking
internally,
or
fluid
is
leaking
externally
.
If
no
leaks
canbe
found,
the
master
cylin-
der
is
faulty
and
should
be
replaced
.
Check
all
Brake
fluid
lines

and
couplings
for
leaks,
kinks,
chafing
and
corrosion
.

Check
the
Brake
booster
by
pumping
the
Brake
pedal
ap-

proximately
10
times
with
the
engine
off
.
Hold
the
pedal
down
and
start
the
engine
.
The
pedal
should
fa¡¡
slightly
.
If
not,
check

for
any
visiblefaults
before
suspecting
a
faulty
brake
booster
.

Check
for
strong
vacuum
at
the
vacuum
hose
fitting
at
the

booster,
and
check
the
non-retum
valve
for
one-way
flow
.

Worn
or
contaminated
brake
pads
will
cause
poor
braking

performance
.
Oil-contaminated
or
glazed
pads
will
cause

stopping
distances
to
increase
.
Inspect
the
rotors
for
glazing,

discoloration
and
scoring
.
Steering
wheel
vibration
while

braking
at
speed
is
often
caused
by
warped
rotors,
but
can
also
be
caused
byworn
suspension
components
.

TROUBLESHOOTING

340-2
BRAKES

When
troubleshooting,
keep
in
mind
that
tire
inflation,
wear

and
temperature
can
affect
braking
and
suspension
.
See310

Front
Suspension
for
more
information
on
front
suspension

parts
inspection
.

Table
a
lists
symptoms
of
brake
problems,
their
probable

causes,
and
suggested
corrective
actions
.

Table
a
.
Brake
System
Troubleshooting

Symptom



1



Probable
cause



1



Repairs

Brake
squeal



a
.
Incorrectly
installed
brake
pads
or



a
.
Check
component
installation
.
parking
brake
shoes
b
.
Brakepad
carriers
dirty
or
corroded



b
.
Remove
brake
pads
and
clean
calipers
.
c
.
Brake
pad
anti-rattle
springs
faulty
or



c
.
Install/replace
anti-rattle
springs
.
missing
d
.
Brakepads
heat-glazed
or
oil-soaked



d
.
Replace
brake
pads
.
Clean
rotors
.
Replace
leaking
calipers
as
required
.
e
.
Wheel
bearings
worn
(noise
most



e
.
Replace
worn
bearings
.
See310
Front
Suspension
pronounced
when
turning)



or
330
Rear
Suspension
.

Pedal
goes
to
f
loor
when
braking



a
.
Brake
fluid
leve¡
low
due
to
system



a
.
Check
fluidlevel
and
inspect
hydraulic
system
for
leaks



signs
of
leakage
.
Fill
and
bleed
system
.
b
.
Master
cylinder
faulty



I
b
.
Replacemaster
cylinder
.

Low
pedal
after
system
bleeding



1
a
.
Master
cylinder
faulty



1
a
.
Replace
master
cylinder
.

Pedal
spongy
or
brakes
work
only



a
.
Air
in
brake
fluid



a
.
Bleedsystem
.
when
pedal
is
pumped



b
.
Master
cylinder
faulty
(interna¡
return



b
.
Replacemaster
cylinder
.
spring
weak)
c
.
Leaking
line
or
hose
unions



c
.
Repair
or
replace
lines
and
hoses
.
Bleed
system
.

Excessive
braking
effort



a
.
Brake
pads
wet



a
.
Use
light
pedal
pressure
to
dry
pads
while
driving
.
b
.
Brake
pads
heat-glazed
oroil-soaked



b
.
Replace
brake
pads
.
Clean
rotors
.
Replace
leaking
calipers
.
c
.
Vacuum
booster
or
vacuum
hose
con-



c
.
Inspect
vacuum
lines
.
Test
vacuum
booster
and
re
nections
to
booster
faulty



place
as
required
.
Test
vacuum
non-return
valve
for
one-way
air
flow
.

Brakes
pulsate,
chatter
or
grab



a
.
Warped
brake
rotors



a
.
Resurface
or
replace
rotors
.
b
.
Brake
padsworn



b
.
Replace
brake
pads
.
c
.
Brake
pads
heat-glazed
or
oil-soaked



c
.
Replace
brake
pads
.
Clean
rotors
.
Replace
leaking
calipers
.

Uneven
braking,
car
pulís
to
one



a
.
Incorrect
tire
pressures
or
worn
tires



a
.
Inspect
tire
condition
.
Check
and
correct
tire
pres-
side,
rear
brakes
lock



sures
.
b
.
Brake
pads
on
one
side
of
car
heat-



b
.
Replace
brake
pads
.
Clean
rotors
.
Replace
leaking
glazed
or
oil-soaked



calipers
.
c
.
Caliper
or
brake
pads
binding



c
.
Clean
and
recondition
brakes
.
d
.
Worn
suspension
components



d
.
Inspect
for
worn
or
damaged
suspension
compo-
nents
.
See
310
Front
Suspension
or
330
Rear
Sus-
pension
.

Brakes
drag,
bind
or
overheat



a
.
Brake
caliper
or
brake
pads
binding



a
.
Clean
or
replace
caliper
.(
b
.
Master
cylinder
faulty



b
.
Replacemaster
cylinder
.

WARNING
-

On
cars
with
All
Season
Traction
(AST),
special
BMW
service
equipment
is
required
to
properly
bleed
the
ABS/AST
system
.
For
safety
reasons,
the
brake
system
on
carswith
ABS/AST
must
not
be
bled
using
the
procedures
described
inthis
repair
group
.

BLEEDING
BRAKES

Brake
bleeding
is
usually
done
for
one
of
two
reasons
:
Ei-
ther
to
replace
oíd
brake
fluid
as
part
of
routine
maintenance
or
to
expel
trapped
air
in
the
system
that
resulted
from
open-
ingthe
brake
hydraulic
system
during
repairs
.

BLEEDING
BRAKES

Alwaysuse
new
brake
fluid
from
an
unopened
container
.It

is
important
to
bleed
the
entire
system
when
any
part
of
the

hydraulic
system
has
been
opened
.
On
cars
not
equipped
with
traction
control
(AST),
brake
system
bleeding
should
be

done
with
a
pressure
bleeder
.
On
cars
with
AST,
brake
bleed-

ing
should
be
done
by
an
authorized
BMW
dealer
.

WARNING
-

On
cars
with
All
Season
Traction
(AST),
special
BMW
service
equipment
is
requíred
to
properly
bleed
the
ABS/AST
system
.
For
safetyreasons,
the
brake
system
on
carswith
ABS/AST
must
not
be
bled
using
the
procedures
described
inthís
repair
group
.