1995 BMW M3 fault
[x] Cancel search: faultPage 242 of 759
260-2
DRIVESHAFT
Further
inspection
requires
removal
of
the
driveshaft
.
Check
the
front
centering
guide
on
the
transmission
output
flange
for
damage
or
misalignment
.
Also
check
runoutatthe
transmission
outputflange
and
output
shaft,
and
at
the
final
drive
input
flange
.
Check
the
bolt
hole
bores
in
theflange
for
wear
and
elongation
.
Driveshaftflange
runout
(max
.
allowable)
"
Transmission
outputflange
axial
play
...
.
..
...
..
.
.......
0
.10
mm
(0
.004
in
.)
radial
play
.......
...
.
.
.......
0
.07
mm
(0
.003
in
.)
"
Final
driveinput
flange
radial
play
(measured
at
driveshaft
centering
lip)
..
......
0
.07
mm
(0
.003
in
.)
Spinthe
center
bearing
and
check
for
the
smooth
operation
without
play
.
Check
that
thesplines
of
the
sliding
coupling
move
freely
.
Clean
and
lubricate
the
splines
with
molybdenum
disulfide
grease
(Molykote
®
Longterm
2
or
equivalent)
.
Check
the
universal
joints
for
wear
or
binding
.
If
any
joint
isdif-
ficult
to
move
or
binds,
the
driveshaft
section
should
be
replaced
.
Table
a
.
Driveshaft
Troubleshooting
NOTE-
With
the
driveshaft
installed,
theactual
amount
that
the
universal
joints
pivot
is
limited
.
For
the
most
accurate
test,
check
universal
joints
in
their
normal
range
of
movement
.
If
inspection
revealsnothing
wrong
with
the
driveshaft,
it
may
need
to
be
rebalanced
.
This
can
be
done
by
a
speciality
driveshaft
repair
shop
.
Also,
check
the
alignment
ofthe
drive-
shaft
as
described
below
.
NOTE-
Minor
driveshaftvibrations
can
often
be
correctedsim-
ply
by
disconnecting
the
driveshaftat
the
finaldrive,
and
repositíoning
the
driveshaft
90°,
180°
or270°
inre-
lationto
the
final
drive
input
flange
.
Table
a
lists
symptoms
of
driveshaft
problems
and
their
probable
causes
.
Most
of
the
repair
information
is
contained
within
this
repair
group
.
Symptom
Probable
cause
Corrective
action
1
.
Vibration
when
a
.
Incorrect
preload
of
center
bearing
.
a
.
Check
preload
of
center
bearing
.
Readjust
preload
.
See
Fig
.
6
.
starting
off
(forward
b
.
Center
bearing
rubber
deteriorated
.
b
.
Inspect
center
bearing
and
rubber
.
Replace
if
necessary
.
orreverse)
.
c
.
Flex-disc
damaged
or
worn
.
c
.
Inspect
flex-disc
.
Replace
if
necessary
.
TROUBLESHOOTING
d
.
Engine
or
transmission
mounts
faulty
.
I
d
.
Inspect
engine
and
transmission
mounts
.
Align
or
replace,
if
nec-
essary
.
e
.
Front
centering
guide
worn,
or
e
.
Check
front
centering
guide
and
replace
if
necessary
.
Check
driveshaft
mounting
flanges
out
of
runout
of
driveshaft
flanges
.
round
.
f
.
Universal
joints
worn
or
seized
.
f
.
Check
universal
joint
play
and
movement
.
Replace
driveshaft
if
necessary
.
g
.
Sliding
coupling
seized
.
g
.
Remove
driveshaft
and
check
movement
of
sliding
coupling
.
Clean
coupling
splines
and
replace
parts
asnecessary
.
h
.
Driveshaft
misaligned
.
h
.
Check
driveshaft
alignment
.
2
.
Noise
during
on/off
a
.
Finaldrive
components
worn
or
a
.
Remove
final
drive
and
repair
.
throttle
or
when
damaged
(excessive
pinion-to-ring-
engagíng
clutch
.
gear
clearance)
.
b
.
Drive
axleor
CV
joint
faulty
.
b
.
Inspect
drive
axles
and
CV
joints
.
Repair
or
replace
as
neces-
sary
.
c
.
Sliding
coupling
seized
.
c
.
Remove
driveshaft
and
check
movement
of
sliding
coupling
.
Clean
coupling
splines
and
replace
parts
as
necessary
.
3
.
Vibration
at
25
to
30
a
.
Front
centering
guideworn,
or
a
.
Check
front
centering
guide
and
replace
if
necessary
.
Check
mph
(40
to
50
driveshaft
mounting
flanges
out
of
runout
of
driveshaft
mounting
flanges
.
km/h
).
round
or
damaged
.
b
.
Universal
joints
worn
or
seized
.
b
.
Check
universal
joint
play
and
movement
.
Replace
driveshaft
if
necessary
.
c
.
Flex-disc
damaged
or
worn
.
c
.
Inspect
flex-disc
.
Replace
if
necessary
.
d
.
Center
bearing
rubber
deteriorated
.
d
.
Inspect
center
bearing
.
Replace
if
necessary
.
e
.
Sliding
coupling
seized
.
e
.
Remove
driveshaft
and
check
movement
of
sliding
coupling
.
Clean
coupling
splines
and
replace
parts
asnecessary
.
f
.
Misaligned
installed
position
.
f
.
Check
driveshaft
alignment
.
Page 243 of 759
Symptom
1
Probable
cause
4
.
Vibration,
audible
a
.
Front
centering
guide
worn,
or
a
.
Check
front
centering
guide
and
replace
if
necessary
.
Check
rumble
over35
mph
driveshaft
mounting
flanges
out
of
runout
of
driveshaft
mounting
flanges
.
(60
km/h)
.
round
or
damaged
.
b
.
Mounting
flange
bolts
loose
or
holes
b
.
Remove
driveshaft
and
check
transmissionoutput
flange
and
worn
.
final
drive
input
flange
.
Replace
if
necessary
.
c
.
Driveshaft
unbalanced
.
c
.
Check
driveshaft
for
loose
or
missing
balance
weights
.
Have
driveshaft
rebalanced
or
replace
if
necessary
.
DRIVESHAFT
SERVICE
Driveshaft,
aligning
d
.
Universal
joints
worn
or
seized
.
d
.
Check
universal
joint
play
and
movement
.
Replace
driveshaft
if
necessary
.
e
.
Sliding
coupling
seized
.
e
.
Remove
driveshaft
and
check
movement
of
sliding
coupling
.
1
Clean
coupling
splines
or
replace
parts
asnecessary
.
f
.
Incorrect
preload
of
center
bearing
.
f
.
Check
preload
of
center
bearing
.
Readjust
if
necessary
.
g
.
Center
bearing
faulty
.
g
.
Replace
center
bearing
.
h
.
Final
drive
rubber
mount
faulty
h
.
Inspect
final
drive
rubber
mount
and
replace
if
necessary
.i.
Driveshaft
misaligned
.
i.
Check
driveshaft
alignment
.
Repair
kits
for
the
universal
joints
are
not
available,
and
it
is
not
common
practice
to
repair
the
universal
joints
on
BMW
driveshafts
.
Worn
or
damaged
universal
joints
usually
require
replacement
of
that
section
of
the
driveshaft
.
The
driveshaft
is
balanced
to
cose
tolerances
.
Whenever
it
is
to
be
removed
or
disassembied,
the
mounting
flanges
and
driveshaft
sections
should
bemarked
with
paint
or
a
punch
before
proceeding
with
work
.
This
will
ensure
that
the
drive-
shaft
can
be
reassembled
or
installed
in
exactlythe
same
ori-
entation
.
Universal
joint
play
"
Maximum
allowable
...........
0.15
mm
(0.006
in
.)
The
alignment
of
the
driveshaft
does
not
normally
need
to
be
checked
unless
the
engine/transmission
orthe
final
drive
havebeen
removed
and
installed
.
If,
however,
all
other
parts
of
the
driveshaft
havebeen
inspected
and
found
to
be
okay,
butthere
is
still
noise
or
vibration,
driveshaft
alignment
should
be
checked
.
There
aretwo
important
driveshaft
alignment
checks
.
The
first
is
to
make
sure
that
the
driveshaft
runs
straight
from
the
transmission
to
the
final
drive
;
without
any
variation
from
side-
to-side
caused
by
misalignment
ofthe
engine/transmission
in
its
mounts
.
Make
a
basic
check
by
sighting
along
the
drive-
shaft
from
back
lo
front
.
Any
misalignmentshould
be
apparent
from
the
center
bearingforward
.
To
adjustthe
side-to-side
alignment,
loosen
the
transmission
or
engine
mounts
to
repo-
sition
them,
then
retighten
the
mounts
:
The
driveshaft
should
be
exactly
centered
in
the
driveshaft
tunnel
.
See
Fig
.
2
.
Table
a
.
Driveshaft
Troubleshooting
(continued)
DRIVESHAFT
260-3
Corrective
action
b
:izó
Fig
.
2
.
Driveshaft
side-to-side
alignment
.
Driveshaft
should
be
cen-
tered
in
driveshaft
tunnel
.
The
second
important
driveshaft
alignment
check
is
more
complicated
.
It
checks
the
amount
the
driveshaft
is
angled
vertically
at
the
joints
.
This
angle
is
known
as
driveshaft
de-
flection
.
In
general,
there
should
be
little
deflection
in
the
driveshaft
between
the
engine,
thecenter
bearing,
and
the
final
drive
.
Precise
checks
require
theuse
of
a
large
protractor
or
some
other
means
of
measuring
the
angle
of
the
engine
and
the
fi-
nal
drive
and
comparing
these
angles
to
the
angle
of
the
drive-
shaft
sections
.
To
change
the
deflection
angle,
shims
can
be
placed
between
the
center
bearing
and
the
body
or
between
the
transmission
and
íts
rear
support
.
When
using
shims
to
change
a
deflection
angle,
keep
in
mind
that
the
angle
of
adjacent
joints
will
also
change
.
Deflection
anglesshould
beas
small
as
possible
.
DRIVESHAFTSERVICE
Page 256 of 759
300-8
SUSPENSION,
STEERING
AND
BRAKES-GENERAL
Tableb
.
Suspension
and
Steering
Troubleshooting
Symptom
1
Probable
cause
Repairs
(Repair
Groups
shown
in
bold)
Car
pulís
to
one
side,
wanders
a
.
Incorrect
tire
pressure
a
.
Check
and
correct
tire
pressures
.
020
b
.
Incorrect
wheel
alignment
b
.
Check
and
adjust
wheel
alignment
.
320
c
.
Faulty
brakes
(pulls
only
when
braking)
I
c
.
Check
for
sticking/damaged
front
caliper
.
340
Steering
heavy,
poor
return-
a
.
Worn
upper
strut
bearing(s)
a
.
Replace
strut
bearings
.
310
to-center
b
.
Incorrect
tire
pressure
b
.
Check
and
correct
tire
pressures
.
020
c
.
Power
steering
system
faulty
c
.
Check
power
steering
fluid
level
.
Test
system
pressure
.
320
Front-end
or
rear-end
vibra-
a
.
Worn
strut
cartridgesor
shock
absorbers
a
.
Replace
strut
cartridges
.
310,
330
tion
or
shimmy
b
.
Worn
suspension
bushings
(control
arm
or
trail-
b
.
Replace
worn
bushings
.
310,
330
ing
arm)
c
.
Worn
front
suspension
ball
joints
(control
arm,
c
.
Replace
worn
ball
joints
.
310
steering
arm
orsteering
tie-rod
end)d
.
Unbalanced
or
bent
wheels/tires
d
.
Balance
tires
.
Check
tiresfor
uneven
wear
pat-
terns
.
Check
wheels
for
damage
.
e
.
Loose
wheel
lug
boits
e
.
Tighten
lug
boits
to
proper
torque
.
Poor
stability,
repeated
bounc-
I
a
.
Worn
strut
cartridgesor
shock
absorbers
I
a
.
Replace
strut
cartridges
.
310,
330
ing
after
bumps,
suspension
bottoms
outeasily
Suspension
noise
(especially
a
.
Worn
front
upper
strut
bearings
a
.
Replaceupper
strut
bearings
.
310
over
bumps)
b
.
Loose
front
strut
cartridge
b
.
Check/tighten
strut
cartridge
collar
nut
.
310
c
.
Worn
suspensionbushings
(control
arm
or
trail-
c
.
Replace
worn
bushings
.
310,
330
ing
arm)d
.
Worn
stabilizer
bar
rubber
mounts
d
.
Replace
stabilizer
bar
rubber
mounts
.
310,
330
e
.
Loose
suspension
crossmember
e
.
Check
crossmember
for
damage
.
Tighten
mounting
boits
.
Uneven
ride
height
a
.
Incorrect
coil
springs
a
.
Measure
ride
height
and
replacesprings
as
re-
quired
.
310,
330
b
.
Bent
or
damaged
suspension
components
b
.
Inspect,
repair/replace
asnecessary
.
310,
330
c
.
Sagging
coil
springs
c
.
Measure
ride
height
and
replace
springs
as
re-
quired
.
310,
330
Wheel
noise,
continuous
I
a
.
Worn
wheel
bearing
I
a
.
Replacewheel
bearing
.
310,
330
growling,
may
be
more
notíce-
able
when
turning
Steering
loose,
imprecise
a
.
Incorrect
tire
pressure
a
.
Check
and
correct
tire
pressures
.
020
-
b
.
Loose
steering
gearmounting
bolt(s)
b
.
Inspect
and
tighten
boits
.
320
c
.
Worn
tie
rodend(s)
c
.
Replace
tie
rod(s)
and
align
wheels
.
320
d
.
Faulty
front
wheel
bearing
d
.
Replace
wheel
bearing
.
310
e
.
Worn
or
damaged
steering
gear
e
.
Adjust
or
replace
steering
gear
.
320
f
.
Worn
tires
f
.
Replace
tires
.
010
SUSPENSION
AND
STEERING
TROUBLESHOOTING
Page 287 of 759
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
Page 289 of 759
Final
driveinputshaft
oil
sea¡,
replacing
1
.
Raise
car
and
support
safely
.
2
.
Drain
final
drive
oil
as
described
earlier
.
3
.
Remove
driveshaft
from
final
drive
inputshaft
flange
.
See
260
Driveshaft
.
4
.
Make
matching
marks
on
input
shaft
and
inputshaft
collar
nut
.
See
Fig
.
4
.
Fig
.
4
.
Make
matching
marks
on
input
shaft
collar
nut
and
flange
.
5
.
Pry
lockplate
from
nut
.
Hold
input
flange
andremove
collar
nut
.
If
necessary,
usea
pullerto
remove
input
flange
.
6
.
Remove
final
drive
front
dust
cover
.
8
.
Install
new
final
drivefront
dust
cover
.
9
.
Lightly
lubricate
inputshaft
and
press
input
flange
back
on
.
Insta¡¡
collar
nut
and
slowly
tighten
until
matching
marks
line
up,
coming
as
close
aspossible
to
specified
torque
.
Tightening
Torques
"
Final
driveinputshaft
flange
to
pinion
with
4
bolt
side
covers
.
.........
175
Nm
(129
ft-Ib)
(or
until
match
marks
line
up)
"
Finaldriveinputshaft
flange
to
pinion
with
6
bolt
side
covers
...........
185
Nm
(137
ft-Ib)
(or
until
match
marks
line
up)
CA
UTION-
If
the
input
flange
nuttorque
is
exceeded,
or
the
nut
is
tightened
past
the
marks,
the
crushable
col-
lar
sleeve
behind
theflange
will
need
to
be
re-
placed
.
This
operation
requires
disassembly
of
the
final
drive
unit
.
10
.
Install
a
new
lockplate
and
refill
final
drive
with
lubri-
cant
.
11
.
Remaining
assembly
is
reverse
of
disassembly
.
Tightening
Torques
"
Driveshaftto
final
dríve
flange
...
See260
Driveshaft
"
Flex-disc
to
driveshaft
or
transmission
flange
...........
See260
Driveshaft
"
Finaldrivedrain
and
fill
plugs
...
.
..
.
70
Nm
(52
ft-Ib)
Final
drive
unit,
removing
and
installing
FINAL
DRIVE
331-
3
1
.
Raise
rear
end
of
car
and
support
it
securely
on
jack
stands
.
Remove
rear
wheels
.
2
.
Remove
driveshaft
from
final
drive
input
flange
.
See
7
.
Pry
faulty
sea¡
from
its
recess
using
a
hooked
sea¡
re-
260
Driveshaft
.
moval
toolor
a
large
screwdriver
.
Dip
new
sea¡
in
final
drive
lubricant
and
drive
it
into
position
.
3
.
Remove
both
drive
axles
from
final
drive
unit
.
Suspend
axle
using
stiff
wire
.
See
330
Rear
Suspension
.
CAUTION
-
ee
careful
not
to
mar
the
housing
when
removing
4
.
Disconnect
stabilizer
bar
from
upper
control
arms
.
Re-
the
seas
.
move
left
and
rightstabilizer
bar
mounts
.
5
.
Disconnect
speedometer
harness
connector
on
final
drive
(where
applicable)
.
6
.
Support
final
drive
with
transmission
jack
.
Remove
mounting
bolts
atfront
and
rear
.
See
Fig
.
5
.
7
.
Slowly
lower
final
drive
unit
and
remove
towards
rear
.
FINAL
DRIVE
SERVICE
Page 291 of 759
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
Page 292 of 759
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
.
Page 295 of 759
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