the crankshaft flange (see illustration). Be
careful - the flywheel is heavy.
5To refit the flywheel/driveplate on the
crankshaft, use a liquid thread-locking
compound on the bolts, and tighten them
gradually, using a criss-cross pattern, to the
torque listed in this Chapter’s Specifications.
6The remainder of refitting is the reverse of
removal.
16 Crankshaft rear oil seal-
renewal
3
1Remove the flywheel or driveplate (see
Section 15).
2Remove the bolts and/or nuts attaching the
seal retainer to the engine block. Be sure to
remove the two bolts (from underneath)
connecting the rear of the sump to the bottom
of the seal retainer (see illustration).
3Run a sharp, thin knife between the sump
gasket and the seal retainer, cutting the
retainer free from the gasket. Be very careful
not to damage the gasket, and keep it clean
so you can re-use it.
4Break the seal retainer-to-block gasket seal
by tapping the retainer with a plastic mallet or
block of wood and hammer. Do not prise
between the retainer and the engine block, as
damage to the gasket sealing surfaces will
result.
5Using a scraper, remove all traces of old
gasket material from the sealing surfaces of
the retainer and engine block. Gasket removal
solvents are available at car accessory shops,
and may prove helpful. After all gasket
material has been removed, the gasket
surfaces can be degreased by wiping them
with a rag dampened with a suitable solvent.
Caution: Be very careful not to
scratch or gouge the delicate
aluminium surfaces. Also, do not
damage the sump gasket, and
keep it clean.
6Support the retainer on two blocks of
wood, and drive out the seal from behind with
a hammer and screwdriver (see illustration).Be very careful not to damage the seal bore in
the process.
7Coat the outside diameter and lip of the
new seal with multi-purpose grease, and drive
the seal into the retainer with a hammer and a
block of wood (see illustration).
8Apply a film of RTV-type gasket sealant to
the surface of the sump gasket that mates with
the seal retainer. Apply extra beads of RTV
sealant to the edges where the gasket meets
the engine block. Note:If the sump gasket is
damaged, instead of fitting a whole new
gasket, you might try trimming the rear portion
of the gasket off at the point where it meets the
engine block, then trim off the rear portion of a
new sump gasket so it’s exactly the same size.
Cover the exposed inside area of the sump
with a rag, then clean all traces of old gasket
material off the area where the gasket was
removed. Attach the new gasket piece to the
sump with contact-cement-type gasket
adhesive, then apply RTV-type sealant as
described at the beginning of this paragraph.
9Coat both sides of the new retainer gasket
with RTV-type gasket sealant, then attach the
gasket to the seal retainer. Fit the seal retainer
to the rear of the engine, then refit the bolts
and tighten them evenly to the torque listed in
this Chapter’s Specifications. Work from bolt-
to-bolt in a criss-cross pattern to be sure
they’re tightened evenly.Note 1:Tighten the
retainer-to-block bolts first, then tighten the
sump-to-retainer bolts.Note 2:After applying
RTV-type sealant, reassembly must becompleted in about 10 minutes so the RTV
won’t prematurely harden.
10Refit the flywheel/driveplate (see Sec-
tion 15).
11Refit the transmission (on vehicles with
manual transmission, see Chapter 7A; on
vehicles with automatic transmission, see
Chapter 7B).
17 Engine mountings-
check and renewal
1
1Engine mountings seldom require attention,
but broken or deteriorated mountings should
be renewed immediately, or the added strain
placed on the driveline components may
cause damage or wear.
Check
2During the check, the engine must be
raised slightly to remove its weight from the
mounts.
3Raise the vehicle and support it securely on
axle stands, then position a jack under the
engine sump. Place a large block of wood
between the jack head and the sump, then
carefully raise the engine just enough to take
its weight off the mounts.
Warning: DO NOT place any part
of your body under the engine
when it’s supported only by a
jack!
In-car engine repair procedures 2A•19
16.6 After removing the retainer from the
block, support it on two wood blocks, and
drive out the old seal with a punch and
hammer16.2 Remove the six bolts from the rear of
the block and the two from underneath at
the sump15.4 Using a socket and ratchet, remove
the eight bolts that hold the flywheel/
driveplate to the crankshaft flange - prevent
the flywheel/driveplate from turning by
locking the ring gear with a lever
17.4 As engine mountings wear or age,
they should be inspected for cracking or
separation from their metal plates
16.7 Drive the new seal into the retainer
with a block of wood, or a section of pipe,
if you have one large enough - make sure
the seal enters the retainer bore squarely
2A
detach them. Pieces of masking tape with
numbers or letters written on them work well
(see illustration).
6Label and detach all coolant hoses from the
engine (see Chapter 3).
7Remove the cooling fan, shroud and
radiator (see Chapter 3). Note:On the M40
engine, it is only necessary to remove the
cooling fan and shroud; however, prevent
damage to the radiator by covering it with a
piece of wood or cardboard.
8Remove the drivebelts (see Chapter 1).
9Disconnect the fuel lines from the fuel rail
(see Chapter 4).
Warning: Fuel is extremely
flammable, so take extra
precautions when you work on
any part of the fuel system. Don’t
smoke, or allow open flames or bare light
bulbs, near the work area, and don’t work
in a garage where a natural gas-type
appliance (such as a water heater or
clothes dryer) with a pilot light is present.
If you spill any fuel on your skin, rinse it off
immediately with soap and water. When
you perform any kind of work on the fuel
system, wear safety glasses, and have a
fire extinguisher on hand.
10Disconnect the accelerator cable (see
Chapter 4) and kickdown linkage/speed
control cable (see Chapter 7B), if applicable,
from the engine.
11Where fitted, unbolt the power steering
pump (see Chapter 10). Leave the lines/hoses
attached, and make sure the pump is kept in
an upright position in the engine compartment
(use wire or rope to restrain it out of the way).
12On air-conditioned models, unbolt the
compressor (see Chapter 3) and set it aside,
or tie it up out of the way. Do not disconnect
the hoses.
13Drain the engine oil (see Chapter 1) and
remove the filter. Remove the engine splash
guard from under the engine.
14Remove the starter motor (see Chapter 5).15Remove the alternator (see Chapter 5).
This is not essential on all models, but it is a
good idea in any case to avoid accidental
damage.
16Unbolt the exhaust system from the
engine (see Chapter 4).
17If you’re working on a vehicle with an
automatic transmission, remove the torque
converter-to-driveplate fasteners (see
Chapter 7B). On the M40 engine, unbolt the
automatic transmission fluid coolant pipes
from the sump.
18Support the transmission with a jack.
Position a block of wood between them, to
prevent damage to the transmission. Special
transmission jacks with safety chains are
available - use one if possible.
19Attach an engine sling or a length of chain
to the lifting brackets on the engine. If the
brackets have been removed, the chain can
be bolted directly to the intake manifold studs,
but place a flat washer between the chain and
the nut, and tighten the nut all the way up to
the chain, to avoid the possibility of the studs
bending.
20Roll the hoist into position and connect
the sling to it. Take up the slack in the sling or
chain, but don’t lift the engine.
Warning: DO NOT place any part
of your body under the engine
when it’s supported only by a
hoist or other lifting device.
21On M10, M20 and M30 engines, remove
the transmission rear crossmember, and
slightly lower the rear of the transmission.
22Remove the transmission-to-engine block
bolts using a Torx socket. Note:The bolts
holding the bellhousing to the engine block
will require a swivel at the socket, and a very
long extension going back towards the
transmission.
23Remove the engine mounting-to-frame
bracket nuts. On the M40 engine, unbolt the
dampers from the mountings.
24Recheck to be sure nothing is still
connecting the engine to the transmission or
vehicle. Disconnect anything still remaining.
25Raise the engine slightly. Carefully work it
forwards to separate it from the transmission.
If you’re working on a vehicle with an
automatic transmission, you may find the
torque converter comes forward with theengine. If it stays with the transmission, leave
it, but you may find it easier to let it come
forward until it can be grasped easier and be
pulled from the crankshaft. Note:When
refitting the torque converter to the
transmission before the engine is refitted, be
sure to renew the transmission front pump
seal, which will probably be damaged when
the converter comes out with the engine.
Either method is acceptable, but be prepared
for some fluid to leak from the torque
converter if it comes out of the transmission. If
you’re working on a vehicle with a manual
transmission, draw the engine forwards until
the input shaft is completely disengaged from
the clutch. Slowly raise the engine out of the
engine compartment. Check carefully to make
sure everything is disconnected.
26Remove the flywheel/driveplate (and
where applicable, the engine rear plate), and
mount the engine on an engine stand (see
illustration). Do not turn the M40 engine
upside-down (see Cautionin Section 4).
Refitting
27Check the engine and transmission
mountings. If they’re worn or damaged, renew
them.
28Refit the flywheel or driveplate (see
Chapter 2A). If you’re working on a manual
transmission vehicle, refit the clutch and
pressure plate (see Chapter 7A). Now is a
good time to fit a new clutch.
29If the torque converter came out with the
engine during removal, carefully refit the
converter into the transmission before the
engine is lowered into the vehicle.
30Carefully lower the engine into the engine
compartment - make sure the engine
mountings line up.
31If you’re working on an automatic
transmission vehicle, guide the torque
converter onto the crankshaft following the
procedure outlined in Chapter 7B.
32If you’re working on a manual
transmission vehicle, apply a dab of high-
melting-point grease to the input shaft, and
guide it into the clutch and crankshaft pilot
bearing until the bellhousing is flush with the
engine block.. Do not allow the weight of the
engine to hang on the input shaft.
33Refit the transmission-to-engine bolts,
and tighten them securely.
Caution: DO NOT use the bolts to
force the transmission and
engine together.
34Refit the remaining components in the
reverse order of removal.
35Add coolant, oil, power steering and
transmission fluid as needed.
2B•6 General engine overhaul procedures
5.26 Removing the engine rear plate -
M40 engine5.5 Label each wire before unplugging the
connector
If there’s any possibility of
confusion, make a sketch of
the engine compartment and
clearly label the lines, hoses
and wires.
It may be necessary to rock
the engine slightly, or to turn
the crankshaft, to allow the
input shaft splines to mate
with the clutch plate
3When examining the bearings, remove
them from the engine block, the main bearing
caps, the connecting rods and the rod caps,
and lay them out on a clean surface in the
same general position as their location in the
engine. This will enable you to match any
bearing problems with the corresponding
crankshaft journal.
4Dirt and other foreign particles get into the
engine in a variety of ways. It may be left in
the engine during assembly, or it may pass
through filters or the crankcase ventilation
(PCV) system. It may get into the oil, and from
there into the bearings. Metal chips from
machining operations and normal engine wear
are often present. Abrasives are sometimes
left in engine components after recondi-
tioning, especially when parts are not
thoroughly cleaned using the proper cleaning
methods. Whatever the source, these foreign
objects often end up embedded in the soft
bearing material, and are easily recognised.
Large particles will not embed in the bearing,
and will score or gouge the bearing and
journal. The best prevention for this cause of
bearing failure is to clean all parts thoroughly,
and to keep everything spotlessly-clean
during engine assembly. Frequent and regular
engine oil and filter changes are also
recommended.
5Lack of lubrication (or lubrication
breakdown) has a number of interrelated
causes. Excessive heat (which thins the oil),
overloading (which squeezes the oil from the
bearing face) and oil “leakage” or “throw off”
(from excessive bearing clearances, worn oil
pump, or high engine speeds) all contribute to
lubrication breakdown. Blocked oil passages,
which usually are the result of misaligned oil
holes in a bearing shell, will also oil-starve a
bearing and destroy it. When lack of
lubrication is the cause of bearing failure, the
bearing material is wiped or extruded from the
steel backing of the bearing. Temperatures
may increase to the point where the steel
backing turns blue from overheating.
6Driving habits can have a definite effect on
bearing life. Full-throttle, low-speed operation
(labouring the engine) puts very high loads onbearings, which tends to squeeze out the oil
film. These loads cause the bearings to flex,
which produces fine cracks in the bearing
face (fatigue failure). Eventually, the bearing
material will loosen in places, and tear away
from the steel backing. Short-trip driving
leads to corrosion of bearings, because
insufficient engine heat is produced to drive
off the condensation and corrosive gases.
These products collect in the engine oil,
forming acid and sludge. As the oil is carried
to the engine bearings, the acid attacks and
corrodes the bearing material.
7Incorrect bearing refitting during engine
assembly will lead to bearing failure as well.
Tight-fitting bearings leave insufficient bearing
oil clearance, and will result in oil starvation.
Dirt or foreign particles trapped behind a
bearing shell result in high spots on the
bearing, which will lead to failure.
21 Engine overhaul-
reassembly sequence
1Before beginning engine reassembly, make
sure you have all the necessary new parts,
gaskets and seals, as well as the following
items on hand:
Common hand tools
A torque wrench
Piston ring refitting tool
Piston ring compressor
Vibration damper refitting tool
Short lengths of rubber or plastic hose to fit
over connecting rod bolts (where
applicable)
Plastigage
Feeler gauges
A fine-tooth file
New engine oil
Engine assembly oil or molybdenum
disulphide (“moly”) grease
Gasket sealant
Thread-locking compound
2In order to save time and avoid problems,
engine reassembly should be done in the
following general order:Piston rings
Crankshaft and main bearings
Piston/connecting rod assemblies
Oil pump
Sump
Cylinder head assembly
Timing belt or chain and tensioner
assemblies
Water pump
Timing belt or chain covers
Intake and exhaust manifolds
Valve cover
Engine rear plate
Flywheel/driveplate
22 Piston rings- refitting
2
1Before fitting the new piston rings, the ring
end gaps must be checked. It’s assumed that
the piston ring side clearance has been
checked and verified (see Section 18).
2Lay out the piston/connecting rod
assemblies and the new ring sets, so that the
ring sets will be matched with the same piston
and cylinder during the end gap measurement
and engine assembly.
3Insert the top ring into the first cylinder, and
square it up with the cylinder walls by pushing
it in with the top of the piston (see illustration).
The ring should be near the bottom of the
cylinder, at the lower limit of ring travel.
4To measure the end gap, slip feeler gauges
between the ends of the ring until a gauge equal
to the gap width is found(see illustration). The
feeler gauge should slide between the ring ends
with a slight amount of drag. Compare the
measurement to this Chapter’s Specifications.
If the gap is larger or smaller than specified,
double-check to make sure you have the
correct rings before proceeding.
5If the gap is too small, it must be enlarged,
or the ring ends may come in contact with
each other during engine operation, which
can cause serious damage to the engine. The
end gap can be increased by filing the ring
ends very carefully with a fine file. Mount the
2B•18 General engine overhaul procedures
22.5 If the end gap is too small, clamp a
file in a vice, and file the ring ends (from
the outside in only) to enlarge the gap
slightly22.4 With the ring square in the cylinder,
measure the end gap with a feeler gauge22.3 When checking piston ring end gap,
the ring must be square in the cylinder
bore (this is done by pushing the ring down
with the top of a piston as shown)
Torque wrench settingsNm
Front disc brake caliper
Caliper guide (mounting) bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 to 35
Caliper bracket-to-strut housing bolts
3-Series, E30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
5-Series, E28 (“old-shape”) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
5-Series, E34 (“new-shape”) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Rear disc brake caliper
Caliper guide (mounting) bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 to 35
Carrier-to-trailing arm bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Brake hose-to-caliper fitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 to 17
Master cylinder-to-brake servo nuts
3-Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
5-Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 to 29
Brake servo mounting nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 to 24
Hydraulic line-to-hydraulic brake servo threaded
fittings - 5-Series, E28 (“old-shape”) . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Wheel bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
9•2 Braking system
1 General information
All 3-Series models, and 5-Series E28 (“old-
shape”) models, are equipped with front disc
brakes and either rear drum or rear disc
brakes. 5-Series E34 (“new-shape”) models
have disc brakes front and rear. Front and
rear brakes are self-adjusting on all models.
Some later models are equipped with an Anti-
lock Braking System (ABS); this is described
in Section 2.
Hydraulic system
The hydraulic system consists of two
separate circuits. The master cylinder has
separate reservoirs for the two circuits; in the
event of a leak or failure in one hydraulic
circuit, the other circuit will remain operative.
Brake servo
The vacuum brake servo, utilising engine
manifold vacuum and atmospheric pressure
to provide assistance to the hydraulically
operated brakes, is mounted on the bulkhead
in the engine compartment.
A hydraulic brake servo system is used on
5-Series E28 models. This system uses
hydraulic pressure from the power steering
pump to assist braking.
Handbrake
The handbrake operates the rear brakes,
and is cable-operated via a lever mounted in
the centre console. The handbrake assembly
on rear drum brake models is part of the rear
drum brake assembly, and is self-adjusting.
On rear disc brake models, the handbrake
uses a pair of brake shoes located inside the
centre portion of the rear brake disc, and is
manually-adjusted.
Brake pad wear warning system
The brake pad wear warning system is
linked to a red warning light in the instrumentcluster, which comes on when the brake pads
have worn down to the point at which they
require renewal. DO NOT ignore this reminder.
If you don’t renew the pads shortly after the
brake pad wear warning light comes on, the
brake discs will be damaged.
On some models, the brake pad wear
warning system also includes an early
warning light that comes on only when the
brake pedal is depressed, letting you know in
advance that the pads need to be renewed.
The wear sensor is attached to the brake
pads. The sensor is located at the left front
wheel; on some models, there is another
sensor at the right rear wheel. The wear
sensor is part of a closed circuit. Once the
pads wear down to the point at which they’re
flush with the sensor, the disc grinds away the
side of the sensor facing the disc. Thus, the
wire inside the sensor is broken, and the red
light on the instrument panel comes on.
Always check the sensor(s) when renewing
the pads. If you change the pads before the
warning light comes on, the sensor(s) may still
be good; once the light has come on, renew
the sensor.
Service
After completing any operation involving
dismantling of any part of the brake system,
always test drive the vehicle to check for
proper braking performance before resuming
normal driving. When testing the brakes, try to
select a clean, dry, road with no camber (ie as
flat as possible) and with no other traffic.
Conditions other than these can lead to
inaccurate test results.
Test the brakes at various speeds with both
light and heavy pedal pressure. The vehicle
should stop evenly, without pulling to one side
or the other. Avoid locking the brakes,
because this slides the tyres and diminishes
braking efficiency and control of the vehicle.
Tyres, vehicle load and wheel alignment are
factors which also affect braking
performance.
2 Anti-lock Braking system
(ABS)- general information
The Anti-lock Braking System is designed
to maintain vehicle control, directional stability
and optimum deceleration under severe
braking conditions on most road surfaces. It
does so by monitoring the rotational speed of
each wheel and controlling the brake line
pressure to each wheel during braking. This
prevents the wheels from locking up.
The ABS system has three main
components - the wheel speed sensors, the
electronic control unit, and the hydraulic
control unit. The sensors - one at each wheel
since 1985, but at both front wheels and one
at the rear differential on earlier models - send
a variable voltage signal to the control unit,
which monitors these signals, compares them
to its program information, and determines
whether a wheel is about to lock up. When a
wheel is about to lock up, the control unit
signals the hydraulic unit to reduce hydraulic
pressure (or not increase it further) at that
wheel’s brake caliper. Pressure modulation is
handled by electrically-operated solenoid
valves.
If a problem develops within the system, an
“ABS” warning light will glow on the
dashboard. Sometimes, a visual inspection of
the ABS system can help you locate the
problem. Carefully inspect the ABS wiring
harness. Pay particularly close attention to the
harness and connections near each wheel.
Look for signs of chafing and other damage
caused by incorrectly-routed wires. If a wheel
sensor harness is damaged, the sensor
should be renewed (the harness and sensor
are integral).
Warning: DO NOT try to repair an
ABS wiring harness. The ABS
system is sensitive to even the
smallest changes in resistance. Repairing
the harness could alter resistance values
6Be sure to inspect the wear sensor(s) (left
front wheel only, or left front and right rear
wheel). If they’re OK, transfer them from the
old pads to the new ones; if they’re worn by
abrasion, fit new sensors on the new pads.
7To fit the new pads, reverse the removal
procedure. When refitting the caliper, be sure
to tighten the mounting bolts to the torque
listed in this Chapter’s Specifications.
Warning: Check and if necessary
renew the mounting bolts on 3-
Series models whenever they are
removed. If in doubt, use new
bolts.
8After the job is completed, firmly depress
the brake pedal a few times, to bring the pads
into contact with the discs. The pedal shouldbe at normal height above the floor, and firm.
Check the level of the brake fluid, adding
some if necessary. Check carefully for leaks,
and check the operation of the brakes before
returning the vehicle to normal service.
9Avoid heavy braking as far as possible for
the first hundred miles or so until the new
pads have bedded in.
4 Disc brake caliper- removal,
overhaul and refitting
4
Warning: Dust created by the
brake system may contain
asbestos, which is harmful to
your health. Never blow it out
with compressed air, and don’t inhale any
of it. An approved filtering mask should be
worn when working on the brakes. Do not,
under any circumstances, use petroleum-
based solvents to clean brake parts. Use
brake system cleaner only!
Warning: Brake fluid is
poisonous. It is also an effective
paint stripper. Refer to the
warning at the start of Section 16.
Note:If an overhaul is indicated (usually
because of fluid leakage), explore all options
before beginning the job. Overhauled calipers
may be available on an exchange basis, which
makes this job quite easy. If you decide to
overhaul the calipers, make sure that anoverhaul kit is available before proceeding.
Always overhaul the calipers in pairs - never
overhaul just one of them.
Removal
1Loosen the wheel bolts, raise the front or
rear of the vehicle, and place it securely on
axle stands. Remove the wheel.
2If you’re just removing the caliper for
access to other components, it isn’t
necessary to detach the brake line. If you’re
removing the caliper for overhaul, disconnect
the brake line from the caliper, for preference
using a split ring (“brake”) spanner to protect
the fitting. Plug the line, to keep contaminants
out of the brake system and to prevent losing
brake fluid unnecessarily.
3Refer to Section 3 for the front or rear
caliper removal procedure - it’s part of the
brake pad renewal procedure. Note:The rear
caliper is similar in design to the front caliper
on 5-series models.
Overhaul
4On all calipers except the front calipers on
3-Series models, remove the circlip for the
dust seal (see illustration),then remove the
dust boot (see illustration). Before you
remove the piston, place a block of wood
between the piston and caliper to prevent
damage as it is removed.
5To remove the piston from the caliper,
apply compressed air to the brake fluid hose
connection on the caliper body (see
9•4 Braking system
3.5l Hang the caliper out of the way with a
piece of wire
3.5m Remove the outer brake pad - to fit
the new pads, reverse the removal
procedure
3.5k Unclip the inner brake pad from the
piston (5-Series)3.5j Remove the caliper and inner brake
pad (5-Series)
3.5i Depress the piston with a C-clamp
(5-Series)3.5h Prise off the anti-rattle spring
(5-Series)3.5g Remove the plugs for the brake
caliper mounting bolts, then remove the
bolts (5-Series)
adjusting screw and contract the handbrake
shoes (see illustration).
Refitting
7Ensure that the disc is completely clean
before refitting. If penetrating oil was used to
remove the disc, make sure that no trace of
this is present. Place the disc on the hub, and
refit the disc retaining screw. Tighten the
screw securely.
8Refit the caliper mounting bracket (if
removed), brake pads and caliper (see
Sections 3 and 4). Tighten all fasteners to the
torques listed in this Chapter’s Specifications.
9Refit the wheel, then lower the vehicle to
the ground. Depress the brake pedal a few
times to bring the brake pads into contact
with the disc.
10Adjust the handbrake shoes, if necessary
(Section 11).
11Check the operation of the brakes
carefully before returning the vehicle to
normal service.
6 Drum brake shoes- renewal
2
Warning: Brake shoes must be
renewed on both wheels at the
same time - never renew the
shoes on only one wheel. Also,
the dust created by the brake system may
contain asbestos, which is harmful to your
health. Never blow it out with compressed
air, and don’t inhale any of it. Always wear
an approved filtering mask when servicing
the brake system. Do not, under anycircumstances, use petroleum-based
solvents to clean brake parts. Use brake
system cleaner only.
Caution: Whenever the brake
shoes are renewed, new return
and hold-down springs and new
automatic adjuster thermo-clips
should also be fitted. Due to the
continuous heating/cooling cycle to which
the springs are subjected, they may lose
their tension over a period of time,
allowing the shoes to drag on the drum,
and wear at a much faster rate than
normal. When fitting new brake shoes, use
only original-equipment or high-quality
brand name parts.
Note 1:All four rear brake shoes must be
renewed at the same time, but to avoid mixing
up parts, work on only one brake assembly at
a time. Some rear brake components are
different for left and right-hand sides, so don’t
mix them up.
Note 2:If the wheel cylinder is found to be
leaking or otherwise defective, renew it after
removing the brake shoes. This is simply a
matter of disconnecting the hydraulic line and
unbolting the cylinder from the backplate.
Attempting to overhaul a leaking cylinder is
unlikely to be satisfactory, even if spare parts
are available.
1Chock the front wheels, then loosen the
rear wheel bolts, raise the rear of the vehicle
and place it securely on axle stands. Remove
the rear wheels and release the handbrake.
2Remove the drum retaining screw (see
illustration)and remove the drum. If the drum
is stuck to the hub, spray the area between
the hub and the drum with penetrating oil
(see illustration). If the drum still won’t come
off, the shoes have probably worn ridges into
the drum, and will have to be retracted. Insert
a narrow flat-bladed screwdriver through one
of the holes in the hub flange (see
illustration)and back off the adjuster wheel
until the drum can be removed.
3Inspect the drum for cracks, score marks,
deep scratches and hard spots, which will
appear as small discoloured areas. If the hard
spots can’t be removed with emery cloth or if
any of the other conditions exist, the drum must
be taken to a specialist to have the drum
resurfaced. Note:Professionals recommendresurfacing the drums whenever a brake job is
done. Resurfacing will eliminate the possibility
of out-of-round drums. If the drums are worn so
much that they can’t be resurfaced without
exceeding the maximum allowable diameter
(which is cast into the drum) (see illustration),
then new ones will be required. At the very least,
if you elect not to have the drums resurfaced,
remove the glazing from the surface with emery
cloth or sandpaper, using a swirling motion.
Braking system 9•7
6.2b If the drum is stuck to the hub, apply
penetrating oil around the hub/drum area,
and give it a few minutes to loosen up
any rust6.2a Removing the drum retaining screw5.6d If a rear disc still sticks to the hub,
insert a thin, flat-bladed screwdriver
through the hub flange, rotate the
starwheel on the handbrake adjusting
screw, and contract the handbrake shoes
(disc removed for clarity)
6.3 The maximum allowable inside
diameter of the drum is cast into the drum
6.2c If the brake shoes have worn a
groove in the drum and it won’t come off,
insert a thin flat-bladed screwdriver
through one of the wheel bolt holes in the
flange, and loosen the automatic adjuster
mechanism (for the sake of clarity, the
drum has already been removed in this
photo, and the screwdriver is being
inserted underneath the flange instead of
though a wheel bolt hole)
9
If the front disc is stuck, on
some discs it is possible to
thread two or three bolts into
the holes provided and
tighten them. Alternate between the
bolts, turning them a couple of turns at
a time, until the disc is free.
friction surfaces of the brake shoes or
drums.
12Make sure the adjuster assembly is
properly engaged with its respective notch in
the handbrake lever.
13When refitting the automatic adjustment
mechanism, fit the lever on the shoe first (see
illustration), then hook the lower end of the
spring onto the lever and the upper end into
its hole in the front shoe (see illustration).
14When you’re done, the brake assembly
should look like this (see illustration). Now
proceed to the other brake.
15When you’re done with both brakes, refit
the brake drums.
16If the wheel cylinder was renewed (see
Note 2), bleed the hydraulic system as
described in Section 16.
17Depress the brake pedal repeatedly to
actuate the self-adjusting mechanism. A
clicking sound will be heard from the brake
drums as the adjusters take up the slack.
18Check the handbrake adjustment (Sec-
tion 11).
19Refit the wheels and bolts. Lower the
vehicle to the ground, and tighten the wheel
bolts to the torque listed in the Chapter 1
Specifications. Check the operation of the
brakes carefully before driving the vehicle in
traffic.
7 Master cylinder-
removal and refitting
3
Warning: Brake fluid is
poisonous. It is also an effective
paint stripper. Refer to the
warning at the start of Section 16.
Note: Although master cylinder parts and
overhaul kits are available for most models, we
recommend fitting a new or overhauled
master cylinder complete. It will take you more
time to overhaul the master cylinder than to
renew it, and you can’t even determine
whether the master cylinder is in good enough
condition to overhaul it until you have
dismantled it. You may very well find that itcan’t be overhauled because of its internal
condition.
Removal
1The master cylinder is connected to the
brake vacuum servo, and both are attached to
the bulkhead, located on the left-hand side of
the engine compartment (see illustration).
2Remove as much fluid as you can from the
reservoir with a syringe.
3Place rags under the line fittings, and
prepare caps or plastic bags to cover the
ends of the lines once they are disconnected.
Caution: Brake fluid will damage
paint. Cover all body parts, and
be careful not to spill fluid during
this procedure.
4Loosen the union nuts at the ends of the
brake lines where they enter the master
cylinder. To prevent rounding off the flats on
these nuts, a split ring (“brake”) spanner,
which wraps around the nut, should be used.
5Pull the brake lines away from the master
cylinder slightly, and plug the ends to prevent
dirt contamination and further fluid loss.
6Disconnect any electrical connectors at the
master cylinder, then remove the nutsattaching the master cylinder to the brake
servo. Pull the master cylinder off the studs,
and lift it out of the engine compartment.
Again, be careful not to spill fluid as this is
done. Discard the old O-ring (see illustration)
between the master cylinder and the servo
unit.
Warning: The O-ring should
always be renewed. A faulty O-
ring can cause a vacuum leak,
which can reduce braking performance
and cause an erratic idle.
Bleeding procedure
7Before fitting a new or overhauled master
cylinder, it should be bled on the bench.
Because it will be necessary to apply pressure
to the master cylinder piston and, at the same
time, control flow from the brake line outlets, it
is recommended that the master cylinder be
mounted in a vice. Use a vice with protected
jaws, and don’t clamp the vice too tightly, or
the master cylinder body might crack.
8Insert threaded plugs into the brake line
outlet holes. Tighten them down so that there
will be no air leakage past them, but not so
tight that they cannot be easily loosened.
9Fill the reservoir with brake fluid of the
recommended type (see “Lubricants, fluids
and capacities” in Chapter 1).
10Remove one plug, and push the piston
assembly into the master cylinder bore to
Braking system 9•9
6.14 When you get everything back
together, this is how it
should look! 6.13b . . . then hook the lower end of the
spring onto the lever as shown; stretch the
spring, and hook the upper end into its
hole in the handbrake shoe6.13a Refit the automatic adjuster lever
first - make sure it’s properly engaged with
the notch in the front end of the
adjuster mechanism . . .
7.6 Always renew the O-ring (1) - groove
arrowed - between the master cylinder and
the brake servo
7.1 To remove the master cylinder, unplug
the electrical connector (top arrow),
disconnect the brake fluid hydraulic line
fittings (lower right arrow, other fitting not
visible in this photo) and remove the two
master cylinder mounting nuts (lower left
arrow, other nut not visible in this photo) -
5-Series master cylinder shown, 3-Series
similar
9
and push it through until the forward end
comes out at the handbrake lever.
8Insert the cable conduit through the
backplate, and attach the rear end of the
cable to the handbrake lever (rear drum
models) or the actuator (rear disc models).
Make sure you don’t kink the cable while
connecting it.
9Refit the cable conduit to the clips on the
back of the trailing arm.
10On rear drum models, refit the brake
shoes and drum (see Section 6). On rear disc
models, refit the handbrake shoes and
actuator (see Section 12) and the rear brake
disc (see Section 5).
11Lower the vehicle, and refit the adjusting
nut at the handbrake lever. Adjust the
handbrake cable (see Section 11) and refit the
handbrake lever boot.
11 Handbrake- adjustment
2
Rear drum brake models
Note:Adjustment of the handbrake cable(s)
on models with rear drum brakes should only
be necessary when you renew a cable or
detach if from the rear brake assembly for
some reason. Failure of the handbrake system
to hold the vehicle usually indicates worn
brake shoes or a faulty self-adjusting
mechanism.
1Raise the rear of the vehicle, and place it
securely on axle stands.
2Fully release the handbrake lever, then
apply the brakes firmly several times with the
footbrake pedal.
3Pull the handbrake lever up five clicks.
4Tighten or loosen the adjusting nuts by
equal amounts until the rear brake shoes just
begin to drag on the brake drum. You should
feel the same amount of resistance at both
wheels when you rotate them.
5Release the handbrake lever, and verify that
the wheels rotate freely. If they don’t, re-
adjust them.
Rear disc brake models
Note: The handbrake system is not self-
adjusting on models with rear disc brakes. The
handbrake therefore requires periodic
adjustment to compensate for wear. It should
also be adjusted anytime either cable, brake
disc or handbrake assembly is renewed or
removed for some reason.
6Slowly apply the handbrake, and count the
number of clicks at the lever. If the lever can
be pulled up further than the eighth click,
adjust the handbrake cable as follows.
7Peel back the handbrake lever boot, and
loosen the cable adjusting nut (see
illustration 10.1). On some models, it may be
necessary to remove the centre console
completely for access.
8Loosen a single bolt in each rear wheel.Raise the vehicle and place it securely on axle
stands.
9Remove the bolt you loosened in each rear
wheel. Turn the wheel until, using a torch, you
can see the adjuster starwheel through the
bolt hole.
10Turn the adjuster - clockwise to expand
the shoes, anti-clockwise to retract them -
until the brake shoes just contact the brake
drum (see illustration 5.6d). Back off the
brake shoes so the wheel spins freely (three to
four teeth on the adjuster). Note:If the
adjuster starwheel is hard to turn, remove the
wheel and brake disc, lubricate the adjuster
wheel, and try again.
11With the disc fitted, apply the handbrake
three times to stretch and seat the cables,
then slowly pull up on the handbrake lever to
the fifth click. Tighten the cable adjusting nuts
by equal amounts until the rear brake shoes
just touch the brake drum. Verify that both
wheels have the same amount of resistance.
12Release the handbrake, and verify that
both rear wheels rotate freely.
13Tighten the wheel bolts to the torque
listed in Chapter 1 Specifications.
12 Handbrake assembly-
check, removal and refitting
2
Warning: The handbrake linings
on rear disc brake models may
be manufactured of asbestos-
based material. Refer to the
warning at the start of Section 6. When
servicing these components, do not create
dust by grinding or sanding the linings.
1The handbrake system should be checked
regularly. With the vehicle parked on a hill,
apply the handbrake, select neutral, and
check that the handbrake alone will hold the
vehicle when the footbrake is released (be
sure to stay in the vehicle during this check).
However, every 2 years (or whenever a fault is
suspected), the assembly itself should be
inspected.
2With the vehicle raised and supported onaxle stands, remove the rear wheels.
3On rear brake drum models, refer to
Chapter 1; checking the thickness of the
brake shoes is a routine maintenance
procedure.
4On rear disc brake models, remove the rear
discs as outlined in Section 5. Support the
caliper assemblies with a coat hanger or
heavy wire; do not disconnect the brake line
from the caliper.
5With the disc removed, the handbrake
components are visible, and can be inspected
for wear and damage. The linings should last
the life of the vehicle. However, they can wear
down if the handbrake system has been
improperly adjusted, or if the handbrake is
regularly used to stop the vehicle. There is no
minimum thickness specification for the
handbrake shoes, but as a rule of thumb, if
the shoe material is less than 1.5 mm thick,
you should renew them. Also check the
springs and adjuster mechanism and inspect
the drum for deep scratches and other
damage.
Removal and refitting
Note:The following procedure applies only to
models with rear disc brakes. The handbrake
system on models with rear drum brakes is an
integral part of the rear brake assembly (see
Section 6).
6Loosen the rear wheel bolts, raise the rear
of the vehicle and place it securely on axle
stands. Remove the rear wheels. Remove the
brake discs (see Section 5). Work on only one
side at a time, so you can use the other side
as a reference during reassembly, and to
avoid mixing up parts.
7Remove the shoe return and hold-down
springs (see illustrations).
8Remove the shoes (see illustration).
9Refitting is the reverse of removal. When
you’re done, the actuator should be properly
seated between the two shoes as shown (see
illustration).
10After refitting the brake disc, adjust the
handbrake shoes. Temporarily refit two wheel
bolts, turn the adjuster (see illustration 5.6d)
and expand the shoes until the disc locks,
9•12 Braking system
12.7b Remove the upper shoe
return spring12.7a Remove the lower shoe return
spring (diagonal cutting pliers are being
used here because they grip the spring
well, but care must be taken not to cut or
nick the spring)