1994 BMW M3 brake sensor

Wheel
bearing

Fig
.
7
.



Rear
wheel
bearing
assembly
.

Circlip



Drive
flange



Collar
nut

0012152

Rear
wheel
bearing,
replacing

1
.
Raise
car
and
support
safely
.
Remove
rear
wheel
.

2
.
Remove
drive
axle
as
described
later
.



6
.
Remove
bearíng
retainer
circlip
from
trailing
arm
.

3
.
Remove
brake
caliper
assembly
and
rotor
as
described



7
.
Using
appropriate
press
tools,
pull
bearing
assembly

in
340
Brakes
.
Leave
brake
hose
connected
to
caliper
.



out
of
trailing
arm
bearing
housing
.

Suspend
caliper
assembly
from
chassís
using
stiff
wire
.

8
.
Inspect
bearing
housing
for
any
damage
or
contamina

4
.
Remove
ABS
pulse
sensor
.
See
Fig
.
8
.



tion
.
Clean
housing
bore
thoroughly
before
installing

new
bearing
.
Make
sure
al¡
thread
bores,
bolts,
nuts

and
mating
surfaces
are
clean

Fig
.
8
.



ABS
pulse
sensor
being
removed
.

5
.
Remove
drive
flange
from
bearing
assembly
.
See
Fig
.

9
.

NOTE-

If
the
inner
bearing
race
remains
attached
to
the
drive

flange,
use
BMW
special
tool
nos
.
007
500
and
33
1

312
or
equivalents
to
separate
inner
race
from
flange
.

REAR
SUSPENSION



330-
5

0013125

Fig
.
9
.



Drive
flange
being
removed
from
bearing
assembly
using
im-
pact
style
puller
.

9
.
Install
new
bearing
assembly
using
press
tools
.
Apply

force
only
to
outer
race
when
installing
bearing
.

WARNING
-

M3
installation
:
redsealing
ríng
on
rear
wheel
bear-

ing
must
face
outward
.
Otherwíse
ABS
will
not
func-
tion
.

10
.
Insta¡¡
new
circlip
.
The
old
circlip
should
never
be
re-

used
.

CAUTION-

Make
sure
that
the
bearing
is
pressed
in
far
enough
to
contact
the
shoulder
at
the
back
sideof
the
housing
and
that
the
circlip
is
fully
seated
in
its
groove
.

11
.
Draw
drive
flange
into
bearing
using
appropriate
press

tools
.
Support
bearing
inner
race
when
pressing
in

0013223



drive
flange
.

NOTE-

BMW
specifies
special
tools
to
pull
the
drive
fiange
through
the
wheel
bearing
into
position
.
If
using
alter-
native
tools,
be
sure
to
support
the
bearing
inner
race
when
pressing
orpulling
the
drive
flange
finto
place
.

REARWHEEL
BEARINGS

330-
1
0



REAR
SUSPENSION

Trailing
arm,
removing
and
installing

1
.
Raise
rear
end
of
car
and
remove
wheel
.

WARNING
-

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
.

2
.
Remove
drive
axle
as
described
earlier
.

3
.
Remove
brake
rotor
and
caliper
as
described
in
340

Brakes
.
Do
not
remove
brake
line
from
caliper
.
Hang

caliper
from
body
with
wire
.

4
.
Remove
parking
brakecable
frombrake
shoe
expand-

er
.
See
340
Brakes
.

5
.
Remove
rear
brake
line
bracket
from
trailing
arm
.
See

Fig
.
17
.

Fig
.
17
.
Brake
line
bracket
bolts
on
trailing
arm
(arrow)
.

WARNING
-

It
is
recommended
that
a
restraining
chain
be
in-
stalled
between
the
bottom
coil
of
the
coil
spring
and
the
upper
control
arm
to
retainthe
spring
in
case
of
accidentalrelease
.
Personal
injury
can
re-sult
if
the
compressed
coil
spring
is
not
released
slow1y
and
carefully
.

REAR
SUSPENSION
ARMS

6
.
Support
trailing
arm
from
below
with
a
transmission
jackorequivalent
.

7
.
Remove
shock
absorber
to
trailing
arm
bolt
.
See
Fig
.
18
.
Slowly
lower
suspension
until
coil
spring
can
be
safely
removed
.

0013220

Fig
.
18
.
Support
trailing
arm
before
removing
lower
shock
bolt
(ar-

row)
.

8
.
Unbolt
upper
and
lower
control
arms
from
trailing
arm,

as
described
later
.

9
.
Remove
ABS
wheel
speed
sensor
from
rear
wheel

bearing
housing
.
Unclip
sensor
wiríng
from
trailing
arm
.

If
removing
right
trailing
arm,
separate
brake
pad
wear

sensor
connector
.
See
Fig
.
19
.

0012104

Fig
.
19
.
Brake
pad
wear
sensor
and
ABS
wheel
speed
sensor
con-
nectors
(arrow)
.

10
.
Remove
three
bolts
holding
trailing
arm
front
bracket
to
body
.
See
Fig
.
20
.
Remove
trailing
arm
.

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

When
bleeding
the
brakes,
startat
the
wheel
farthest
from



4
.
Close
bleeder
screw
and
release
brake
pedal
.
Refill
the
master
cylinder
and
progress
in
the
following
order
:



brake
fluid
reservoir
and
proceed
to
rear
left
wheel
.

"
right
rear
brake



5
.
Proceed
with
the
remaining
wheels
using
the
order
list-

"
left
rear
brake



ed
earlier
.

"
rightfront
brake

"
left
front
brake

Pressure
bleeding
brakes

(except
carswith
AST)

1
.
Top
off
brake
fluid
in
reservoir
and
connect
pressure

bleeder
to
reservoir
.
Connect
bleeder
hose
and
bottle
to
right
rearcaliper
bleeder
screw
.
Pressurize
system

to
approximately
1
bar
(14
.5
psi)
.

BRAKES
340-
3

Tightening
Torques

"
Bleeder
screws
:

7
mm
screw
..........
..
.
.
.
.
......
5
Nm
(4
ft-Ib)

9
mm
screw
..........
..
.
..
.......
6
Nm
(5
ft-Ib)

BRAKE
PADS,
CALIPERS,
AND
ROTORS

CAUTION-



TheE36
front
brake
caliper
is
shown
in
Fig
.
2
.
The
rear

Do
not
exceed
a
pressure
of
2
bar
(29
psi)
when



brake
caliper
is
shown
in
Fig
.
7
.

pressure
bleeding
the
brake
system
.
Excessive
pressure
will
damage
the
brake
fluid
reservoir
.



Brake
pads
canbe
replaced
without
disconnecting
the
brake
fluid
hose
from
the
caliper
or
having
to
bleed
the
brakes
.

2
.
Have
a
helperhold
brake
pedal
down
.



The
rotors
can
be
replaced
without
disassembling
the
wheel
huband
bearing
.
Always
machine
or
replace
rotors
in
parts
.

3
.
Open
bleeder
screw
.
See
Fig
1
.
Have
helper
slowly
,



Replace
pads
in
sets
.

pump
brakes
about10
times
with
bleeder
screw
open,

holding
pedal
down
on
the
last
pump
.
When
escaping



WARNING-

fluid
is
free
of
air
bubbles,
close
bleeder
screw
.



"
Althoughsemi-metallicandmetallicbrake
friction
materials
in
brake
pads
or
shoes
no
longer
con

CAUTION-



tain
asbestos,
they
produce
dangerous
dust
.

Bleeder
hose
must
alwaysremain
submersed
in



"
Treat
all
brake
dust
asa
hazardous
material
.
the
clean
brake
fluid
whenever
the
bleeder
valve
is
open
.



"
Do
not
create
dust
by
grinding,
sanding,
orclean-
ing
brake
friction
surfaces
with
compressed
air
.

"
Breathing
any
brake
dust
can
cause
serious
dis-
eases
such
as
cancer,
and
may
result
in
death
.

Brake
pads,
replacing

This
procedure
is
applicable
lo
both
front
and
rear
brakes
.

Front
and
rear
brake
assemblies
are
basically
the
same,
ex-

cept
that
the
rear
brake
rotors
house
the
parking
brake
mech-

anism

1
.
Raise
car
andremove
wheels
.

WARNING
-

Make
sure
thecar
is
firmly
supported
onjack
stands
designed
for
the
purpose
.
Place
the
jack
stands
be-
neath
a
structural
chassis
point
.
Do
not
place
jack
stands
undersuspension
parts
.

2
.
Remove
plastic
caps
from
guide
bolts
and
then
remove

guide
bolts
.
See
Fig
.
3
.

0012113



3
.
If
applicable,
disconnect
brake
pad
wear
sensor
con-
Fig
.
1
.



Brake
caliper
bleeder
screw
(arrow)
.



nector
and
remove
wiring
from
its
holder
.

4
.
Remove
anti-rattle
clip
from
caliper
.
See
Fig
.
4
.

BRAKE
PADS,
CALIPERS,
AND
ROTORS

340-
4
BRAKES

Fig
.
2
.



Front
brake
caliper
assembly
.

Bleeder
valve
and
dust
cap

Mounting
bolt

Brake
pad
wearsensor
(left
wheel
only)

-
Brake
pad
.
carrier
Anti-rattle
^_
spring-

0012154

Fig
.
3
.



Brake
caliper
guide
bolts
(arrows)
.

5
.
Pull
caliper
straight
off
rotor
.

CAUTION-

Do
not
let
the
brake
cafiper
hang
from
the
brake
hose
.
Suspend
ft
from
the
chassis
using
stiff
wire
.

BRAKE
PADS,
CALIPERS,
AND
ROTORS

0012155

Fig
.
4
.



Removing
anti-rattle
clip
by
unhooking
at
top
and
bottom
.
Use
screwdriver
asan
aid
(arrow)
.

NOTE-

If
there
is
a
ridge
on
the
rotor
edge,
the
cafiper
pfston
will
have
to
be
pushed
back
finto
the
cafiper
before
the
cafiper
can
be
removed
.

6
.
Remove
brake
pads
from
caliper
.
Where
applicable,
carefully
pry
pad
wear
sensor
from
pad
.
See
Fig
.
5
.

Fig
.
5
.



Removing
brake
pad
wear
sensor
.

7
.
Inspect
brake
caliper
for
signs
of
leakage
.
Check
that
the
caliper
piston
slides
smoothly
into
caliper
.
Replace
caliper
if
any
faults
are
found
.

CAUTION-

With
the
pads
removed,
residual
hydreulic
pres-
sure
may
cause
the
caliper
piston
to
slide
out
.
Use
a
wooden
block
to
hold
the
piston
in
place
.

8
.
fnsert
brake
pad
wear
sensor
into
cutout
in
new
pad

where
applicable
.

14
.
Place
inner
brake
pad
(with
locating
spring)
ontobrake
NOTE-



caliper
piston
.
Route
pad
wear
sensor
wiring
through
lf
the
brake
lining
indicator
light
illuminated
prior
to



caliper
opening
and
bleeder
dust
cap
.
brake
pad
replacement,
the
wear
sensor
should
be
re-
placed
.



15
.
The
remainder
of
installation
is
reverse
of
removal
.

"
Do
not
lubricate
guide
boits
.
9
.
Slowly
press
piston
back
into
caliper
.
Use
cace
not
to



"
Once
brake
assembly
is
installed
depress
brakepedal
damage
piston
dust
sea¡
.
See
Fig
.
6
.



severa¡
times
before
driving
vehicle
.

NOTE-

"
Open
caliper
bleeder
screw
when
pressing
piston



Tightening
Torques

back
into
caliper
.
Catch
expelled
fluidin
appropriate



"
Brake
caliper
to
brake
pad

container
.
This
procedure
is
highly
recommended
in



carrier
(guide
bolt)
..........
...
.
.
30
Nm
(22
ft-Ib)

the
case
of
cars
with
ABS
.



"
Road
wheel
to
hub



.....
.
..
100±10
Nm
(74±7
ft-Ib)

"
Open
the
bleeder
screw
only
when
applying
force
to
the
piston
.
Do
not
allow
airto
be
drawn
in
through
the
bleeder
screw
.

"
Pressing
the
caliper
piston
in
may
cause
the
brake
flu-
id
reservoir
to
overflow
.
To
prevent
this,
use
a
clean
syringe
to
first
remove
some
fluid
from
the
reservoir
.

BRAKES
340-
5

0012157
Fig
.
6
.



Brake
caliper
piston
being
pressed
into
caliper
to
make
room
for
new
pads
.
Usea
rag
toprotect
caliper
piston
and
seals
.

10
.
Thoroughly
clean
inner
and
outer
surfaces
of
brake
ro-
tor
.
Inspect
rotor
for
cracks,
signs
of
overheating
and
0012156
scoring
.

11
.
Measure
thickness
of
rotor
.
See
Table
b
.
If
rotor
does
not
pass
minimum
thickness
requirements,
or
is
dam-

aged,
replace
as
described
later
.

12
.
Thoroughly
clean
all
contact
points
on
caliper
and
brake
pad
carrier
.
Clean
guide
bolts
and
make
surethey
slide
freely

13
.
Lightly
coat
pad
contact
points
with
brake
anti-squeal
paste
.
Place
outer
brake
pad
onto
caliper
.
Applya
small
amount
of
grease
to
thetop
and
bottom
contact
points
where
the
caliper
contacts
the
pad
carrier
.

BRAKE
PADS,CALIPERS,
ANDROTORS

340-
6BRAKES

bolt~



Guide
bolt

caps
covers
Brake
caliper
Shoe
retaining
píns

Parking
brake
cable

Fig
.
7
.



Rear
brake
caliper
assembly
.

Caliper
guide



Brake



ad
bolts
,



Bleeder
valve



i
_
~wear
sénsor
®



and
dust
cap



(right
wheel
V
.
.,,,

Brake
caliper,
removing
and
installing

1
.
Raise
car
and
remove
wheel
.

WARNING
-

Make
sure
the
car
is
firmly
supported
on
jack
standsdesigned
for
the
purpose
.

2
.
Loosen
brake
hose
fitting
at
caliper
.
Do
not
remove
.

3
.
Remove
caliper
mounting
bolts
from
steering
arm
(Font

caliper)or
from
trailing
arm
(rear
caliper)
.
See
Fig
.
8
.

4
.
Press
piston
back
into
caliper
and
slide
caliper
off
brake

rotor
.
Spin
caliper
off
brake
hose
.

5
.
Inspect
brake
caliper
for
signs
of
leakage
.
Check
that
caliper
piston
slides
smoothly
into
caliper
.
Replace
cal-

iper
if
any
faults
are
found
.

6
.
Installation
is
reverse
of
removal
.
Bleed
entire
brake

system
before
driving
car
.
See
Bleeding
Brakes
.

Tightening
Torques

"
Front
brake
caliper
to
steering
arm
..
110
Nm
(81
ft-Ib)

"
Rear
brake
caliper
to
trailing
arm
....
67
Nm
(50
ft-Ib)

"
Brake
fluid
hose
to
caliper
....
17-19
Nm
(13-14
ft-Ib)

"
Road
wheel
to
hub



........
100±10
Nm
(74±7
ft-Ib)

BRAKE
PADS,CALIPERS,
ANDROTÓRS

Cover

Caliper



!



Brake
pad
Oringiston



carne
-
p

Circli

©
ot~
AV
~:
Z



1vo~
Spring
and
spring
retainer



uust
seas



~~



Aniráttle

j),
Brake



spring
Shoe
pads
_
_

adjuster



per
return

nf

MIL

Rotor
with
integrated
parking
brake
drum
6573

0011256

Fig
.
8
.



Front
brake
pad
carrier
mounting
bolts
(arrows)
.
Rear
caliper
mounting
bolts
are
similar
.

340-
1
2
BRAKES

ABS
is
self-tested
by
the
ABS
diagnostic
unit
each
time
the
car
is
started
.
Once
the
test
is
complete,
the
ABS
dashboard
light
tucos
off
.
If
the
light
remains
lit
or
comes
on
at
any
time
during
driving,
a
system
fault
has
occurred
and
ABS
is
elec-
tronically
disabled
.
The
conventional
braking
systemremains
fully
functioning
.

ABS
Inspection

A
visual
inspection
of
the
ABS
may
help
to
locate
system
faults
.
If
no
visual
faults
can
befound
and
the
ABS
light
re-
mains
on,
have
the
system
diagnosedbyan
authorized
BMW
dealer
.

Carefully
inspect
the
entire
ABS
wiring
harness,
particularly

the
pulse
sensorharnesses
and
connectors
near
each
wheel
.

Look
for
chafing
or
damage
due
to
incorrectly
routed
wires
.

Carefully
remove
the
wheelspeed
sensors
.
Clean
the
sen-



Fig
.
18
.
Front
ABS
pulse
sensor
mounting
bolt
(arrow)
.
sor
tips
.
Inspect
the
toothed
wheel
on
thewheel
hub
.
Check
for
missing,
clogged
or
corroded
teeth,
or
other
damage
that
could
alter
the
clearance
between
the
sensor
tip
and
the
toothed
wheel
.

NOTE-

If
a
toothed
ring
is
damaged,
the
entire
wheel
hub
mustbe
reptaced
.
See
310
Front
Suspension
or330
Rear
Suspension
.

ABS
wheel
speed
sensors,
replacing

1
.
Raise
applicable
end
of
car
.

WARNING
-

Make
sure
thecar
is
firmly
supportedon
jack
stands
designed
for
the
purpose
.
Place
the
jack
stands
be-
neath
a
structural
chassis
point
Do
not
place
jack
stands
under
suspension
parts
.

2
.
Unscrew
wheelspeed
sensor
mounting
bolt
.
Remove
sensor
from
its
housing
.
See
Fig
.
18
.
Remove
harnessfrom
retaining
mounts
.

3
.
Front
ABS
sensor
:
Working
in
front
wheel
housing,
dis-
connect
and
remove
sensor
.
See
Fig
.
19
.

4
.
Rear
ABS
sensor
:
Working
in
rear
wheel
housing,
dis-
connect
andremove
sensor
.

5
.
During
installation,
apply
thin
coat
of
Molykote
0
Long-
term
2
or
an
equivalent
grease
to
pulse
sensor
and
housing
.

ANTILOCK
BRAKE
SYSTEM
(ABS)

0012122
Fig
.
19
.
Front
ABS
wheel
speed
electrical
connector
(arrow)
in
wheel
well
.

6
.
Installation
is
reverse
of
removal
.