BMW 325i 1994 E36 Workshop Manual

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
.

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
.

Brake
rotor,
removing
and
installing

Brake
rotors
shouldalways
be
replaced
in
pairs
.

Fig
.
9
.



Brake
rotor
mounting
screw
(arrow)
.

3
.
Inspect
rotor
for
excessive
grooving,
cracks,
and
warp-

ing
.
Check
rotor
thickness
.
See
Table
b
.

4
.
Installation
is
reverse
of
removal
.

"
Clean
rotor
with
brakecleaner
before
installing
.

"
If
brake
fluid
hose
veas
removed
or
loosened,
brake

systemmustbe
bled
as
described
aboveunder

Bleeding
Brakes
.

BRAKES
340-
7

5
.
Once
brake
assembly
is
instalind,
depress
brakepedal

several
times
to
adjust
caliper
and
pads
.

"
Pedal
should
feel
firm
and
be
at
proper
height
.

"
Check
fluid
leve¡
.
Top
up
if
necessary
.

NOTE-

M3
models
use
directional
brake
rotors
and
mustbe
in-



NOTE-

stalled
on
the
proper
side
.
Part
numbes
are
cast
finto



When
installing
new
rear
brake
rotors,
the
parking

therotors
.
A
part
that
ends
in
an
odd
number
is
a
left



brakeshouldbe
adjusted
.
See
Parking
Brake
.

rotor
.
One
that
ends
in
an
even
number
is
a
right
rotor
.

1.
Remove
caliper
as
described-above
and
hang
from



Tightening
Torques
chassis
using
stiff
wire
.



"
Brake
rotor
to
wheel
hub
..........
16
Nm
(12
ft-Ib)

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

NOTE-



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

Do
notloosen
caliper
brake
hose
.



"
Road
wheel
to
hub



...
..
.
100
±
10
Nm
(74
t
7
ft-Ib)

2
.
Remove
mountingscrew
holding
rotor
to
wheel
hub
.



,

See
Fig
.
9
.



Table
b
.
Brake
Rotor
Reconditioning
Specificati*M`

Front
Rear

Vented
rotor
wear
limit
(min
.
thickness)



20
.4
mm
(0
.803
in.)

Solid
rotor
wear
limit
(min
.
thickness)



8
.4
mm
(0.331
in
.)

M3
models
wear
limit
(min
.
thickness)



26
.4mm
(0
.977
in
.)



18
.4
mm
(0
.723
in
.)

Axial
runout
(max
.)
rotor
removed



0
.05
mm
(0
.002
in
.)



0
.05
mm
(0
.002
in
.)
rotor
installed



0
.20
mm
(0
.008
in
.)



0
.20
mm
(0
.008
in
.)

CAUTION-

M3
brake
rotors
must
not
be
machined
.

MASTER
CYLINDER

The
brake
master
cylinder
is
mounted
to
the
front
of
the
vac-

uum
booster
on
the
driver
side
bulkhead
.

Master
cylinder,
removing
and
installing

1
.
Using
a
clean
syringe,
empty
brake
fluid
reservoir
.

WARNING
-

Brake
fluid
is
highly
corrosive
and
dangerous
to
the

environment
.
Dispose
of
it
properly
.

NOTE-

On
original
equipment
rotors,
the
mínimum
allowable



2
.
Disconnect
brake
fluid
leve¡
sender
connector
from
fluid

thickness
is
stamped
on
the
rotor
hub
.
Measure
the
rotor



reservoi
r
cap
.

brakingsurface
with
a
micrometer
at
eight
to
ten
different

points
and
use
the
smallest
measurement
recorded
.



3
.
Disconnect
brake
fluid
lines
frommaster
cylinder
.
See

Fig
.
10
.
Disconnect
hydraulic
clutch
system
supply
line
.

4
.
Unscrew
mounting
nuts
and
remove
master
cylinder

from
brake
booster
.

5
.
Make
sure
all
nuts,
fluid
couplings,
thread
bores,
and

mating
surfaces
are
clean
.

MASTER
CYLINDER

340-
8
BRAKES

Fig
.
10
.
Brake
fluid
linesat
master
cylinder
(arrows)
.

6
.
If
fluid
reservoir
was
removed,
install
it
carefully
using
new
sealing
grommets
.

7
.
Mount
master
cylinder
to
brake
booster
using
a
new
0-
ring
and
new
self-locking
nuts
.

CAUTION-

Use
cave
not
to
over-torque
the
master
cylinder
mounting
nuts
.
This
could
damage
the
brake
booster
and
prevent
proper
vacuum
build-up
.

0012164

8
.
Connect
all
brake
fluid
lines
.
Connect
hydraulic
clutch
hose
to
brake
fluid
reservoir
.

9
.
Reconnect
fluid
leve¡
sender,
and
bleed
entire
brake
systemas
described
earlier
.

BRAKE
BOOSTER

BRAKE
BOOSTER

The
brake
booster
is
mounted
to
the
bulkhead
on
the
driver
sideofthe
engine
compartment,
directly
behind
the
brake
master
cylinder
.
See
Fig
.
11
.

0015225
Fig
.
11
.
Brake
booster
(arrow)
.
A
is
vacuum
hose
from
intake
mani-
fold
.
B
is
one-way
valve
.
Intake
manifold
vacuum
acts
ona
large
diaphragm
in
the
brake
booster
to
reducebrake
pedal
effort
.

Brake
booster,
removing
and
installing

1
.
Disconnect
negative
(-)
cable
from
battery
.

CAUTION-

Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
onpage
vi¡¡
.

Tightening
Torque

"
Brake
master
cylinder
to



2
.
Using
a
clean
syringe,
empty
brake
(luid
reservoir
.

brake
booster
.....
..
.
..
.........
26
Nm
(18
ft-Ib)



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



Brake
fluid
is
highly
corroslve
and
dangerous
to
the
environment
.
Dispose
of
it
properly
.

3
.
Remove
brake
fluid
level
sender
connector
from
reser-
voir
cap
.

4
.
Disconnectbrake
fluid
lines
from
master
cylinder
.
Plug
openings
.

5
.
Disconnect
engine
vacuum
hose
from
brake
booster
.

6
.
Disconnect
ABS
electrical
connectors
.
Label
and
then

disconnect
brake
lines
from
hydraulic
brake
unit
.
Plug

openíngs
.
See
Fig
.
12
.

~
~
A
1/
B
'1v
C
~
F

lu
11
-ri
J
.

0013244
A
.
Right
front



F



Front
from
master
cylinder
B
.
Leftfront



R
.
Rear
from
master
cylinder
C
.
Rear

Fig
.
12
.
Brake
fluid
linesat
ABS
hydraulic
unit
.

WARNING
-

"
On
cars
with
All
Season
Traction
(AST),
special
BMW
service
equipment
is
required
to
properly
bleed
the
Antilock
Brake
System
(ABS)
.
Removal
of
the
ABS
hydraulic
unit
is
not
recommended
un-
less
this
equipment
is
available
.
For
safetyrea-
sons,
the
brake
system
on
cars
with
ABS
must

not
be
bled
using
the
procedures
described
inthis
repair
group
.

"
Do
not
mix
up
the
fluid
fines
at
the
ABS
hydraulic
unit
Label
all
connections
before
disconnecting
.

7
.
Remove
ABS
hydraulic
unit
from
engine
compartment
.

8
.
Working
inside
car,
remove
panel(s)
frombeneath

steering
column
to
access
pedal
assembly
.
See513
In-

terior
Trim
.

12
.
Make
sure
al¡
nuts,
fluid
couplings,
thread
bores
and

mating
surfaces
are
clean
.

BRAKES
340-
9

0011261

Fig
.
13
.
Brake
pedal
clevispin
and
retaining
clip
(A)
.
Brake
booster
mounting
nuts
shown
at
arrows
.

13
.
If
necessary,
mount
master
cylinder
to
vacuum
booster

using
a
new
O-ríng
and
newself-locking
nuts
.

CAUTION-

Do
not
over-torque
the
master
cylinder
mounting
bolts
.
This
could
damage
the
brake
booster
and
prevent
proper
vacuum
build-up
.

14
.
Installation
is
reverse
of
Rmoval
.

"
Bleed
brakes
as
described
earlier
.

"
Check
and,
if
necessary,
adjust
brake
light
switch

above
brake
pedal
.

Tightening
Torques

"
Brakemaster
cylinder
to

brake
booster
...........
.
..
..
...
26
Nm
(18
ft-Ib)

"
Brake
booster
to
bulkhead
.
.
..
..
...
22
Nm
(16
ft-Ib)

"
Brake
fluidline
to
master
cylinder
or

ABS
hydraulic
unit
.......
.
..
17-19
Nm
(13-14
ft-lb)
9
.
Remove
clip
and
clevis
pin
from
brake
booster
pushrod

and
disconnect
it
from
brakepedal
.
Remove
brake

booster
mounting
nuts
.
See
Fig
.
13
.
NOTE-

10
.
Working
in
engine
compartment,
remove
brake
booster



When
replacing
the
brake
booster
one-way
valve
or
together
with
master
cylinder
.



vacuum
hose,
install
the
valve
so
that
the
molded
arrow

is
pointing
toward
the
intake
manifold
.
Use
new
hose

11
.
If
booster
or
master
cylinder
O-ring
is
being
replaced,



clamps
.

disconnect
master
cylinder
from
brake
booster
.

BRAKE
BOOSTER

340-
1
0
BRAKES

PARKING
BRAKE

The
parking
brake
is
a
brake
drum
system
integrated
into
the
rear
brake
rotors
.
See
Fig
.
14
.

Adjustment
of
the
shoes
may
benecessary
compensate
for
wear
.
The
parking
brake
should
also
be
adjusted
any
time
the
cable,
the
rear
brake
rotor,
or
the
parking
brake
shoes
are
re-
placed
.

Lower
Parking
brake



Parking
brake



retum
shoe
actuator
spring

Fig
.
14
.
Parking
brake
shoeassembly
.

Parking
brake,
adjusting

2
.
Raise
rearof
car
.

PARKING
BRAKE

Shoe
retainer



Rotor
with
and
spring



integrated
parking
brake

Shoe



drum
I

adjuster



Upper
return
spring

-í
<~
:
:

Rotor
mounting
screw

WARNING
-

Make
sure
the
car
is
firmly
supported
on
jack
stands
designed
for
the
purpose
.
Place
the
jack
stands
be-
neatha
structural
chassis
point
.
Do
not
placejack
stands
undersuspension
parts
.

0011265
3
.
Remove
one
lug
bolt
from
each
rear
wheel
.
Turnroad
wheel
until
lug
bolt
hole
lines
úp
with
parking
brake
ad-
juster
(approximately
65°
to
rear
of
wheel
centerline)
.
See
Fig
.
16
.

4
.
Usinga
screwdriver,
turn
adjusterto
expand
brake
shoes
until
road
wheel
canno
longer
turn,
then
back
adjuster
off
.
Repeatprocedureon
other
rear
wheel
.

Fig
.
15
.
Parking
brake
cable
adjustingnuts
(arrows)
.

The
parking
brake
can
be
adjusted
with
the
wheels
in-

stalled,
although
the
rear
wheels
will
have
to
be
raised
off
the



1



f
l



i\
aground
.

1
.
Lift
parking
brake
lever
boot
out
of
console
.
While
hold-
ing
cables
stationary,
loosen
parking
brake
cable
nuts
until
cablesare
completely
slack
.
See
Fig
.
15
.

0011263
0012727

Fig
.
16
.
Access
parking
brake
shoe
adjuster
approxímately
65°
to
rear
of
vertical
.
Use
flat-bladed
screwdriver
to
turnadjuster
.
On
left
wheel,
turn
adjuster
in
direction
1
to
expand
shoes
.
On
ríght
wheel,
turn
adjuster
in
direction
2
to
expand
shoes
.

Parking
Brake
Adjusting
(initial)

"
Back
off
adjuster
through
wheel
lug
bolt
hole
ex
.
M3
models
.........
..
...
...
.
...
.
18notches
M3
models
............
.
.....
..
..
..
.
.
8notches
5
.
Working
inside
car,
set
parking
brake
several
times
to
seat
cable
.
Then
pull
parking
brake
lever
up
four
notch-
es
.
Tighten
cable
adjusting
nuts
until
it
is
just
possible
to
turnrear
wheels
with
slight
resistance
.

6
.
Release
lever
and
make
sure
rear
wheels
turn
freely
.