brake fluid BMW 3 SERIES 1990 E30 User Guide

Caution: Do not overfill the
reservoir. If too much fluid is
added, remove the excess with a
clean syringe. Refit the cap.
7If frequent topping-up is needed, check the
power steering hoses and connections for
leaks and wear (see Section 10).
8Check the condition and tension of the
drivebelt (see Section 11).
8 Automatic transmission fluid
level check
1
Caution: The use of transmission
fluid other than the type listed in
this Chapter’s Specifications
could result in transmission
malfunctions or failure.
1The automatic transmission fluid should be
carefully maintained. Low fluid level can lead
to slipping or loss of drive, while overfilling
can cause foaming and loss of fluid. Either
condition can cause transmission damage.
2Since transmission fluid expands as it heats
up, the fluid level should only be checked
when the transmission is warm (at normal
operating temperature). If the vehicle has just
been driven over 20 miles (32 km), the
transmission can be considered warm. You
can also check the fluid level when the
transmission is cold. If the vehicle has not
been driven for over five hours and the fluid is
about room temperature (20°C), the
transmission is cold. However, the fluid level
is normally checked with the transmission
warm, to ensure accurate results.
Caution: If the vehicle has just
been driven for a long time at
high speed or in city traffic, in hot
weather, or if it has been pulling
a trailer, an accurate fluid level reading
cannot be obtained. Allow the trans-
mission to cool down for about 30 minutes.
3Immediately after driving the vehicle, park it
on a level surface, apply the handbrake and
start the engine. While the engine is idling,
depress the brake pedal and move theselector lever through all the gear ranges,
beginning and ending in Park.
4The automatic transmission dipstick tube is
located in the left rear corner of the engine
compartment.
5With the engine still idling, pull the dipstick
out of the tube (see illustration), wipe it off
with a clean rag, push it all the way back into
the tube and withdraw it again, then note the
fluid level.
6The level should be between the two marks
(see illustration). If the level is low, add the
specified automatic transmission fluid through
the dipstick tube - use a clean funnel,
preferably equipped with a fine mesh filter, to
prevent spills.
Caution: Be careful not to
introduce dirt into the
transmission when topping up.
7Add just enough of the recommended fluid
to fill the transmission to the proper level. It
takes about half a litre to raise the level from
the low mark to the high mark when the fluid
is hot, so add the fluid a little at a time, and
keep checking the level until it’s correct.
8The condition of the fluid should also be
checked along with the level. If the fluid is
black or a dark reddish-brown colour, or if it
smells burned, it should be changed (see
Section 28). If you are in doubt about its
condition, purchase some new fluid, and
compare the two for colour and smell.
9 Tyre rotation
1
1The tyres can be rotated at the specified
intervals, or whenever uneven wear is noticed.
However, bear in mind that if rotation
succeeds in making all the tyres wear evenly,
you will eventually have to renew all four at
once. Since the vehicle will be raised and the
wheels removed anyway, check the brakes
also (see Section 26). Note: Even if you don’t
rotate the tyres, at least check the wheel bolt
tightness.
2It is recommended that the tyres be rotatedin a specific pattern (see illustration)so that
their direction of rotation remains the same.
3Refer to the information in “Jacking and
towing”at the front of this manual for the
proper procedure to follow when raising the
vehicle and changing a tyre.
4The vehicle must be raised on a hoist or
supported on axle stands to get all four tyres
off the ground. Make sure the vehicle is safely
supported!
5After the rotation procedure is finished,
check and adjust the tyre pressures as
necessary, and be sure to check the wheel
bolt tightness.
10 Underbonnet hose check
and renewal
3
Warning: Renewal of air
conditioning hoses must be left
to a dealer service department or
air conditioning specialist having
the equipment to depressurise the system
safely. Never disconnect air conditioning
hoses or components until the system has
been depressurised.
General
1High temperatures under the bonnet can
cause deterioration of the rubber and plastic
hoses used for various systems. Periodic
inspection should be made for cracks, loose
clamps, material hardening, and leaks.
2Information specific to the cooling system
can be found in Section 22, while the braking
system is covered in Section 26.
3Most (but not all) hoses are secured with
clamps. Where clamps are used, check to be
sure they haven’t lost their tension, allowing
the hose to leak. If clamps aren’t used, make
sure the hose has not expanded and/or
hardened where it slips over the fitting,
allowing it to leak.
Vacuum hoses
4It’s quite common for vacuum hoses,
especially those in the emissions system, to
be colour-coded or identified by coloured
1•13
9.2 The tyre rotation pattern for these
models8.6 With the fluid hot, the level should be
kept between the two dipstick notches,
preferably near the upper one8.5 The automatic transmission fluid
dipstick (arrowed) is located near the
bulkhead on the left side of the engine
compartment
1
Every 6000 miles

stripes moulded into them. Various systems
require hoses with different wall thicknesses,
collapse resistance and temperature
resistance. When fitting new hoses, be sure
the new ones are made of the same material.
5Often the only effective way to check a
hose is to remove it completely from the
vehicle. If more than one hose is removed, be
sure to label the hoses and fittings to ensure
correct refitting.
6When checking vacuum hoses, be sure to
include any plastic T-fittings in the check.
Inspect the connections for cracks which
could cause leakage.
7A small piece of vacuum hose can be used
as a stethoscope to detect vacuum leaks.
Hold one end of the hose to your ear and
probe around vacuum hoses and fittings,
listening for the “hissing” sound characteristic
of a vacuum leak.
Warning: When probing with the
vacuum hose stethoscope, be
careful not to touch moving
engine components such as the
drivebelt, cooling fan, etc.
Fuel hoses
Warning: There are certain
precautions which must be taken
when servicing or inspecting fuel
system components. Work in a
well-ventilated area, and do not allow open
flames (cigarettes, appliance pilot lights,
etc.) or bare light bulbs near the work
area. Mop up any spills immediately, and
do not store fuel-soaked rags where they
could ignite. 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.
8The fuel hoses are usually under pressure,
so if any fuel hoses are to be disconnected,
be prepared to catch spilled fuel.
Warning: On vehicles equipped
with fuel injection, you must
depressurise the fuel system
before servicing the fuel hoses.
Refer to Chapter 4 for details.9Check all rubber fuel hoses for deterioration
and chafing. Check especially for cracks in
areas where the hose bends, and just before
connectors, such as where a hose attaches to
the fuel pump or fuel filter, for example.
10Only high-quality fuel hose should be
used. Never, under any circumstances, use
unreinforced vacuum hose, clear plastic
tubing or water hose for fuel hoses.
11Band-type clamps are commonly used on
fuel hoses. These clamps often lose their
tension over a period of time, and can be
“sprung” during removal. Renew all band-type
clamps with screw clamps whenever a hose is
renewed.
Metal lines
12Sections of metal line are often used
between the fuel pump and fuel injection
system. Check carefully to make sure the line
isn’t bent, crimped or cracked.
13If a section of metal line must be renewed,
use seamless steel tubing only, since copper
and aluminium tubing do not have the
strength necessary to withstand the vibration
caused by the engine.
14Check the metal brake lines where they
enter the master cylinder and brake
proportioning or ABS unit (if used) for cracks
in the lines and loose fittings. Any sign of
brake fluid leakage calls for an immediate
thorough inspection of the braking system.
Power steering hoses
15Check the power steering hoses for leaks,
loose connections and worn clamps. Tighten
loose connections. Worn clamps or leaky
hoses should be renewed.
11 Drivebelt check, adjustment
and renewal
1
Check
1The drivebelts, sometimes called V-belts or
simply “fan” belts, are located at the front of
the engine, and play an important role in the
overall operation of the vehicle and itscomponents. Due to their function and
material make-up, the belts are prone to
failure after a period of time, and should be
inspected and adjusted periodically to prevent
major engine damage.
2The number of belts used on a particular
vehicle depends on the accessories fitted.
Drivebelts are used to turn the alternator,
power steering pump, water pump, and air
conditioning compressor. Depending on the
pulley arrangement, a single belt may be used
to drive more than one of these components.
3With the engine switched off, open the
bonnet and locate the various belts at the
front of the engine. Using your fingers (and a
torch, if necessary), move along the belts,
checking for cracks and separation of the belt
plies. Also check for fraying and glazing,
which gives the belt a shiny appearance (see
illustration). Both sides of the belts should be
inspected, which means you will have to twist
each belt to check the underside.
4The tension of each belt is checked by
pushing firmly with your thumb and seeing
how much the belt moves (deflects). Measure
the deflection with a ruler (see illustration). A
good rule of thumb is that the belt should
deflect 6 mm if the distance from pulley
centre-to-pulley centre is between 180 and
280 mm. The belt should deflect 13 mm if the
distance from pulley centre-to-pulley centre is
between 300 and 400 mm.
Adjustment
5If it is necessary to adjust the belt tension,
either to make the belt tighter or looser, it is
done by moving a belt-driven accessory on its
bracket. (When the same belt drives more
than one accessory, normally only one
accessory is moved when making
adjustment.)
6For each component, there will be an
adjusting bolt and a pivot bolt. Both bolts
must be loosened slightly to enable you to
move the component. On some components,
the drivebelt tension can be adjusted by
turning an adjusting bolt after loosening the
lockbolt (see illustration).
7After the two bolts have been loosened,
1•14
11.6 Loosen the nut on the other end of
the adjuster bolt (arrowed) and turn the
bolt to increase or decrease tension on the
drivebelt11.4 Measuring drivebelt deflection with a
straightedge and ruler11.3 Here are some of the more common
problems associated with drivebelts
(check the belts very carefully to prevent
an untimely breakdown)
Every 6000 miles

4Since some components of the fuel system
- the fuel tank and some of the fuel feed and
return lines, for example - are underneath the
vehicle, they can be inspected more easily
with the vehicle raised on a hoist. If that’s not
possible, raise the vehicle and support it on
axle stands or ramps.
5With the vehicle raised and safely
supported, inspect the fuel tank and filler neck
for punctures, cracks or other damage. The
connection between the filler neck and the
tank is particularly critical. Sometimes a
rubber filler neck will leak because of loose
clamps or deteriorated rubber. Inspect all fuel
tank mounting brackets and straps, to be sure
the tank is securely attached to the vehicle.
Warning: Do not, under any
circumstances, try to repair a fuel
tank (except rubber
components). A welding torch or
any naked flame can easily cause fuel
vapours inside the tank to explode.
6Carefully check all flexible hoses and metal
lines leading away from the fuel tank. Check
for loose connections, deteriorated hoses,
crimped lines, and other damage. Repair or
renew damaged sections as necessary (see
Chapter 4).
22 Cooling system check
1
1Many major engine failures can be
attributed to cooling system problems. If the
vehicle has automatic transmission, the
engine cooling system also plays an importantrole in prolonging transmission life, because it
cools the transmission fluid.
2The engine should be cold for the cooling
system check, so perform the following
procedure before the vehicle is driven for the
day, or after it has been switched off for at
leastthree hours.
3Remove the radiator cap, doing so slowly
and taking adequate precautions against
scalding if the engine is at all warm. Clean the
cap thoroughly, inside and out, with clean
water. Also clean the filler neck on the
radiator. The presence of rust or corrosion in
the filler neck means the coolant should be
changed (see Section 29). The coolant inside
the radiator should be relatively clean and
clear. If it’s rust-coloured, drain the system
and refill with new coolant.
4Carefully check the radiator hoses and the
smaller-diameter heater hoses. Inspect each
coolant hose along its entire length, renewing
any hose which is cracked, swollen or
deteriorated (see illustration). Cracks will
show up better if the hose is squeezed. Pay
close attention to hose clamps that secure the
hoses to cooling system components. Hose
clamps can pinch and puncture hoses,
resulting in coolant leaks.
5Make sure all hose connections are tight. A
leak in the cooling system will usually show up
as white or rust-coloured deposits on the area
adjoining the leak. If wire-type clamps are
used on the hoses, it may be a good idea to
replace them with screw-type clamps.
6Clean the front of the radiator (and, where
applicable, the air conditioning condenser)
with compressed air if available, or a soft
brush. Remove all flies, leaves, etc,
embedded in the radiator fins. Be extremely
careful not to damage the cooling fins or to
cut your fingers on them.
7If the coolant level has been dropping
consistently and no leaks are detected, have
the radiator cap and cooling system pressure-
tested.
23 Exhaust system check
1
1The engine should be cold for this check,
so perform the following procedure before the
vehicle is driven for the day, or after it has
been switched off for at leastthree hours.
Check the complete exhaust system from the
engine to the end of the tailpipe. Ideally, the
inspection should be done with the vehicle on
a hoist, to give unrestricted access. If a hoist
isn’t available, raise the vehicle and support it
securely on axle stands or ramps.
2Check the exhaust pipes and connections
for evidence of leaks, severe corrosion, and
damage. Make sure that all brackets and
mountings are in good condition, and that
they are tight (see illustration).
3At the same time, inspect the underside of
the body for holes, corrosion, open seams,etc. which may allow exhaust gases to enter
the passenger compartment. Seal all body
openings with suitable sealant.
4Rattles and other noises can often be
traced to the exhaust system, especially the
mountings and heat shields. Try to move the
pipes, silencers (and, where applicable, the
catalytic converter). If the components can
come in contact with the body or suspension
parts, re-hang the exhaust system with new
mountings.
5The running condition of the engine may be
checked by inspecting inside the end of the
tailpipe. The exhaust deposits here are an
indication of the engine’s state of tune. If the
pipe is black and sooty, the engine may be
running too rich, indicating the need for a
thorough fuel system inspection.
24 Steering and suspension
check
1
Note: The steering linkage and suspension
components should be checked periodically.
Worn or damaged suspension and steering
linkage components can result in excessive
and abnormal tyre wear, poor ride quality and
vehicle handling, and reduced fuel economy.
For detailed illustrations of the steering and
suspension components, refer to Chapter 10.
Strut/shock absorber check
1Park the vehicle on level ground, turn the
engine off and apply the handbrake. Check
the tyre pressures.
2Push down at one corner of the vehicle,
then release it while noting the movement of
the body. It should stop moving and come to
rest in a level position with one or two
bounces.
3If the vehicle continues to move up and
down, or if it fails to return to its original
position, a worn or weak strut or shock
absorber is probably the reason.
4Repeat the above check at each of the
three remaining corners of the vehicle.
5Raise the vehicle and support it on axle
stands.
6Check the struts/shock absorbers for
evidence of fluid leakage. A light film of fluid is
1•21
22.4 Hoses, like drivebelts, have a habit of
failing at the worst possible time - to
prevent the inconvenience of a blown
radiator or heater hose, inspect them
carefully as shown here
23.2 Check the exhaust system rubber
mountings for cracks
1
Every 12 000 miles

no cause for concern. Make sure that any fluid
noted is from the struts/shocks, and not from
any other source. If leakage is noted, renew
the struts or shock absorbers in axle pairs (or
as a full set).
7Check the struts/shock absorbers to be
sure that they are securely mounted and
undamaged. Check the upper mountings for
damage and wear. If damage or wear is
noted, renew the struts or shock absorbers.
8If the struts or shock absorbers must be
renewed, refer to Chapter 10 for the
procedure. Always renew both units on the
same axle, or the safety of the vehicle may be
compromised. If possible, renew all four as a
set.
Steering and suspension check
9Inspect the steering system components
for damage and distortion. Look for leaks and
damaged seals, boots and fittings.
10Clean the lower end of the steering
knuckle. Have an assistant grasp the lower
edge of the tyre and move the wheel in and
out, while you look for movement at the
steering knuckle-to-axle arm balljoints.
Inspect the balljoint boots for tears (see
illustration). If there is any movement, or the
boots are torn or leaking, the balljoint(s) must
be renewed.
11Grasp each front tyre at the front and rear
edges, push in at the front, pull out at the rear
and feel for play in the steering linkage. If any
free play is noted, check the steering gear
mountings and the track rod balljoints for
looseness. If the steering gear mountings are
loose, tighten them. If the track rods are
loose, the balljoints may be worn (check to
make sure the nuts are tight). Additional
steering and suspension system information
can be found in Chapter 10.
25 Driveshaft gaiter check
1
1The driveshaft gaiters are very important
because they prevent dirt, water and foreign
material from entering and damaging the
constant velocity (CV) joints. External oil and
grease contamination can cause the gaitermaterial to deteriorate prematurely, so it’s a
good idea to wash the gaiters with soap and
water.
2Inspect the gaiters for tears and cracks, as
well as for loose clamps (see illustration). If
there is any evidence of cracks or leaking
lubricant, the gaiter must be renewed (see
Chapter 8).
26 Brake system check
2
Warning: Dust produced by lining
wear and deposited on brake
components may contain
asbestos, which is hazardous to
your health. Do not blow it out with
compressed air, and don’t inhale it! Do not
use petroleum-based solvents to remove
the dust. Brake system cleaner or
methylated spirit should be used to flush
the dust into a drain pan. After the brake
components are wiped with a damp rag,
dispose of the contaminated rag(s) and the
drain pan contents into a covered and
labelled container. Try to use asbestos-
free new parts whenever possible.
Note:In addition to the specified intervals, the
brake system should be inspected each time
the wheels are removed or a malfunction is
indicated. Because of the obvious safety con-
siderations, the following brake system checks
are some of the most important maintenance
procedures you can perform on your vehicle.
Symptoms of brake system
problems
1The disc brakes have built-in electrical wear
indicators which cause a warning light on the
dash to come on when they’re worn to the
renewal point. When the light comes on,
renew the pads immediately, or expensive
damage to the brake discs could result.
2Any of the following symptoms could
indicate a potential brake system defect:
a) Vehicle pulls to one side when the brake
pedal is depressed
b) Brakes make squealing or dragging noises
when applied
c) Brake pedal travel excessived) Brake pedal pulsates (normal if ABS is
working)
e) Brake fluid leaks (usually on the inner side
of the tyre or wheel)
3If any of these conditions are noted, inspect
the brake system immediately.
Brake lines and hoses
Note: Steel brake pipes are used throughout
the brake system, with the exception of
flexible, reinforced hoses at the front wheels
and as connectors at the rear axle. Periodic
inspection of all these lines is very important.
4Park the vehicle on level ground, and
switch off the engine. Remove the wheel
covers. Loosen, but do not remove, the bolts
on all four wheels.
5Raise the vehicle and support it securely on
axle stands.
6Remove the wheels (see “Jacking and
towing” at the front of this book, or refer to
your owner’s handbook, if necessary).
7Check all brake lines and hoses for cracks,
chafing of the outer cover, leaks, blisters, and
distortion. Check the brake hoses at front and
rear of the vehicle for softening, cracks,
bulging, or wear from rubbing on other
components. Check all threaded fittings for
leaks, and make sure the brake hose
mounting bolts and clips are secure.
8If leaks or damage are discovered, they
must be repaired immediately. Refer to
Chapter 9 for detailed brake system repair
procedures.
Disc brakes
9If it hasn’t already been done, raise the
vehicle and support it securely on axle stands.
Remove the front wheels.
10The disc brake calipers, containing the
pads, are now visible. Each caliper has an
outer and an inner pad - all pads should be
checked.
11Note the pad thickness by looking
through the inspection hole in the caliper (see
illustration). If the lining material is 2.0 mm
thick or less, or if it is tapered from end to
end, the pads should be renewed (see
Chapter 9). Keep in mind that the lining
1•22
26.11 Look through the caliper inspection
window to inspect the brake pads - the
pad lining which rubs against the disc can
also be inspected by looking through each
end of the caliper25.2 Gently probe the driveshaft boots to
check for cracks24.10 Inspect the balljoint boots for tears
(arrowed)
Every 12 000 miles

material is bonded to a metal plate or shoe -
the metal portion is not included in this
measurement. Always renew the pads on
both sides of the vehicle (in axle sets), even if
only one pad of the four is worn, or uneven
braking may result.
12Remove the calipers without
disconnecting the brake hoses (see Chap-
ter 9).
13Check the condition of the brake disc.
Look for score marks, deep scratches and
overheated areas (they will appear blue or
discoloured). If damage or wear is noted, the
disc can be removed and resurfaced by an
engineering workshop; otherwise, it will have
to be renewed. In either case, both discs
should be involved, even if only one is worn.
Refer to Chapter 9 for more detailed
inspection and repair procedures.
Drum brakes
14Refer to Chapter 9 and remove the rear
brake drums.
15Note the thickness of the lining material
on the rear brake shoes, and look for signs of
contamination by brake fluid or grease (see
illustration). If the material is within 2.0 mm of
the recessed rivets or metal shoes, renew the
brake shoes. The shoes should also be
renewed if they are cracked, glazed (shiny
lining surfaces), or contaminated with brake
fluid or grease. See Chapter 9 for the renewal
procedure.
16Check the shoe return and hold-down
springs and the adjusting mechanism. Make
sure all these components are fitted correctly,and are in good condition. Deteriorated or
distorted springs, if not renewed, could allow
the linings to drag and wear prematurely.
17Check the wheel cylinders for leakage by
carefully peeling back the rubber boots. Slight
moisture behind the boots is acceptable. If
brake fluid is noted behind the boots or if it
runs out of the wheel cylinder, the wheel
cylinders must be overhauled or renewed (see
Chapter 9).
18Check the drums for cracks, score marks,
deep scratches and high spots, which will
appear as small discoloured areas. If
imperfections cannot be removed with emery
cloth, both drums must be resurfaced by a
specialist (see Chapter 9 for more detailed
information).
19Refer to Chapter 9 and fit the brake
drums.
20Refit the wheels, but don’t lower the
vehicle yet.
Handbrake
21The easiest, and perhaps most obvious,
method of checking the handbrake is to park
the vehicle on a steep hill with the handbrake
applied and the transmission in Neutral (stay
in the vehicle while performing this check). If
the handbrake doesn’t prevent the vehicle
from rolling, refer to Chapter 9 and adjust it.
27 Wiper blades -
check and renewal
1
1Road film can build up on the wiper blades
and affect their efficiency, so they should bewashed regularly with a mild detergent
solution.
Check
2The wiper and blade assembly should be
inspected periodically. If inspection reveals
hardened or cracked rubber, renew the wiper
blades. If inspection reveals nothing unusual,
wet the windscreen, turn the wipers on, allow
them to cycle several times, then switch them
off. An uneven wiper pattern across the glass,
or streaks over clean glass, indicate that the
blades should be renewed.
3The operation of the wiper mechanism can
loosen the retaining nuts, so they should be
checked and tightened, as necessary, at the
same time the wiper blades are checked (see
Chapter 12 for further information regarding
the wiper mechanism).
Wiper blade renewal
4Pull the wiper/blade assembly away from
the glass.
5Press the retaining tab in, and slide the
blade assembly down the wiper arm (see
illustration).
6If you wish to renew the blade rubbers
separately, detach the end of the rubber from
the wiper blade frame, then slide the rubber
out of the frame (see illustration).
7Compare the new rubber with the old for
length, design, etc.
8Slide the new rubber into place, and insert
the end in the wiper blade frame to lock it in
place.
9Refit the blade assembly on the arm, then
wet the glass and check for proper operation.
1•23
27.6 Detach the end of the wiper element
from the end of the frame, then slide the
element out27.5 Press the retaining tab in, then slide
the wiper blade assembly down and out of
the hook in the end of the wiper arm26.15 If the lining is bonded to the brake
shoe, measure the lining thickness from
the outer surface to the metal shoe, as
shown here (A); if the lining is riveted to
the shoe, measure from the lining outer
surface to the rivet head
1
Every 12 000 miles
Every 24 000 miles or 2 years, whichever comes first
28 Automatic transmission fluid
and filter change
1
1At the specified intervals, the transmission
fluid should be drained and renewed. Since
the fluid will remain hot long after driving,perform this procedure only after the engine
has cooled down completely.
2Before beginning work, purchase the
specified transmission fluid (see “Lubricants
and fluids”at the beginning of this Chapter)
and a new filter.
3Other tools necessary for this job include axle
stands or ramps to support the vehicle in araised position, a drain pan capable of holding at
least 4.5 litres, and newspapers and clean rags.
4Raise the vehicle and support it securely.
5Loosen the dipstick tube collar, then detach
the dipstick tube and let the fluid drain (see
illustrations).
6Remove the transmission sump mounting
bolts and brackets (see illustration).

7Detach the sump from the transmission and
lower it, being careful not to spill the
remaining fluid (see illustration).
8Carefully clean the sump-to-transmission
contact surface.
9Pour the fluid from the sump into a suitable
container, then clean the sump with solvent
and dry it with compressed air. Be sure to
clean any metal filings from the magnet, if
applicable.
10Remove the filter from inside the
transmission (see illustrations).
11Fit the O-ring and a new filter, being sure
to tighten the bolts securely.
12Make sure that the sump gasket contact
surfaces are clean, then fit the new gasket.
Offer the sump up to the transmission, and
refit the brackets and bolts. Working aroundthe sump, tighten each bolt a little at a time
until the torque listed in this Chapter’s Specifi-
cations is reached. Don’t overtighten the
bolts! Connect the dipstick tube, and tighten
the collar securely.
13Lower the vehicle, and add the specified
amount of fluid through the filler tube (see
Section 8).
14With the transmission in Park and the
handbrake applied, run the engine at fast idle,
but don’t race it.
15Move the gear selector through each
position, and back to Park. Check the fluid
level.
16Check under the vehicle for leaks after the
first few trips.
29 Cooling system -draining,
flushing and refilling
1
Warning: Do not allow antifreeze
to come in contact with your skin,
or with the painted surfaces of the
vehicle. Rinse off spills
immediately with plenty of water. Antifreeze
is highly toxic if ingested. Never leave
antifreeze lying around in an open container
or in puddles on the floor; children and pets
are attracted by its sweet smell, and may
drink it. Check with local authorities about
disposing of used antifreeze. Local
collection centres may exist to see that
antifreeze is disposed of safely.1Periodically, the cooling system should be
drained, flushed and refilled. This will restore
the effectiveness of the antifreeze mixture and
prevent formation of rust and corrosion, which
can impair the performance of the cooling
system and cause engine damage. When the
cooling system is serviced, all hoses and the
radiator cap should be checked and renewed
if necessary.
Draining
2If the vehicle has just been driven, wait
several hours to allow the engine to cool down
before beginning this procedure.
3Once the engine is completely cool, remove
the expansion tank cap or radiator cap. If the
cap must be removed while the engine is still
warm, unscrew it slowly, and take adequate
precautions to avoid scalding.
4Move a large container under the radiator to
catch the coolant. Where a drain plug is fitted,
unscrew it (a pair of pliers or screwdriver may
be required to turn it, depending on the
model) (see illustration). Where there is no
drain plug, it will be necessary to disconnect
the bottom hose from the radiator.
5While the coolant is draining, check the
condition of the radiator hoses, heater hoses
and clamps (see Section 21 if necessary).
6Renew any damaged clamps or hoses (see
Chapter 3 for detailed renewal procedures).
1•24
28.10c Remove the O-ring from the
transmission. If it is in good condition,
clean it and transfer it to the new fluid
filter; otherwise, renew it
28.10b . . . then remove the fluid filter from
the transmission28.10a Use a Torx key to remove the filter
bolts . . .
28.7 Lower the sump from the
transmission
28.6 Use a socket and extension to
remove the bolts and brackets28.5b Detach the tube and let the fluid
drain28.5a Unscrew the dipstick tube collar
Every 24 000 miles

9
General
Brake fluid type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Disc brakes
Minimum brake pad thickness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Brake disc minimum permissible thickness (wear limit)*
Front
3-Series
Solid discs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.7 mm
Ventilated discs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.0 mm
5-Series
Solid discs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.0 mm
Ventilated discs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.0 mm
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.0 mm
Brake disc minimum thickness after machining
Front
3-Series
Solid discs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 mm
Ventilated discs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.4 mm
5-Series
Solid discs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.4 mm
Ventilated discs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.4 mm
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4 mm
Parallelism (difference between any two measurements) . . . . . . . . . . . 0.02 mm
Maximum disc run-out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.2 mm
*Refer to marks cast into the disc (they supersede information printed here)
Brake pedal adjustments
Brake pedal/servo pushrod adjustment (A) (3-Series) . . . . . . . . . . . . . . 125 mm
Brake pedal height (pedal-to-bulkhead distance)
3-Series
Left-hand-drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235 mm
Right-hand-drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 mm
5-Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 mm
Stop-light switch adjustment (dimension A - see text) . . . . . . . . . . . . . . 5.0 mm to 6.0 mm
Handbrake
Handbrake shoe lining minimum thickness . . . . . . . . . . . . . . . . . . . . . . 1.5 mm
Handbrake lever travel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 to 8 clicks
Chapter 9 Braking system
Anti-lock brake system (ABS) - general information . . . . . . . . . . . . . 2
Brake check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Brake disc - inspection, removal and refitting . . . . . . . . . . . . . . . . . 5
Brake fluid level check . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Brake hoses and lines - inspection and renewal . . . . . . . . . . . . . . . . 15
Brake hydraulic system - bleeding . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Brake pedal - adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Brake vacuum servo - check, removal and refitting . . . . . . . . . . . . . 8
Disc brake caliper - removal, overhaul and refitting . . . . . . . . . . . . . 4Disc brake pads - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Drum brake shoes - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Handbrake assembly - check, removal and refitting . . . . . . . . . . . . 12
Handbrake - adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Handbrake cable(s) - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Hydraulic brake servo - description, removal and refitting . . . . . . . . 9
Master cylinder - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . 7
Stop-light switch - check and adjustment . . . . . . . . . . . . . . . . . . . . 14
9•1
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert
DIY or professional
Degrees of difficulty
Specifications Contents

and cause the system to malfunction. If
the ABS wiring harness is damaged in any
way, it must be renewed.
Caution: Make sure the ignition is
turned off before unplugging or
re-making any electrical
connections.
Diagnosis and repair
If the dashboard warning light comes on
and stays on while the vehicle is in operation,
the ABS system requires attention. Although
special electronic ABS diagnostic testing
tools are necessary to properly diagnose the
system, you can perform a few preliminary
checks before taking the vehicle to a dealer
service department.
a) Check the brake fluid level in the
reservoir.
b) Verify that the electronic control unit
connectors are securely connected.
c) Check the electrical connectors at the
hydraulic control unit.
d) Check the fuses.
e) Follow the wiring harness to each front
and rear wheel, and verify that all
connections are secure and that the
wiring is undamaged.
If the above preliminary checks do not
rectify the problem, the vehicle should bediagnosed by a dealer service department.
Due to the complex nature of this system, all
actual repair work must be done by a dealer
service department.
3 Disc brake pads- renewal
2
Warning: Disc brake pads must
be renewed on both front wheels
or both rear wheels at the same
time - NEVER renew the pads 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. 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! When servicing the disc brakes, use
only original-equipment or high-quality
brand-name pads.
Warning: Brake fluid is
poisonous. It is also an effective
paint stripper. Refer to the
warning at the start of Section 16.
Note:This procedure applies to both the front
and rear disc brakes.
1Remove the cap(s) from the brake fluid
reservoir, and syphon off about two-thirds of
the fluid from the reservoir. Failing to do thiscould result in the reservoir overflowing when
the caliper pistons are pressed back into their
bores.
2Loosen the wheel bolts, raise the front or
rear of the vehicle and support it securely on
axle stands.
3Remove the front or rear wheels, as
applicable. Work on one brake assembly at a
time, using the assembled brake for reference
if necessary.
4Inspect the brake disc carefully as outlined
in Section 5. If machining is necessary, follow
the information in that Section to remove the
disc, at which time the pads can be removed
from the calipers as well.
5Follow the accompanying photos,
beginning with illustration 3.5a, for the pad
removal procedure. Be sure to stay in order,
and read the caption under each illustration.
Note 1:Different types of front calipers are
used on 3 and 5-Series models. Illustrations
3.5a to 3.5e are for the front calipers on 3-
Series models.Illustrations 3.5f to 3.5m are
for the front calipers on 5-Series models.
There’s no photo sequence for rear calipers;
although slightly different in size, they’re
identical in design to the front brake calipers
used on 5-Series models.Note 2: Some
models may have different numbers and types
of anti-squeal shims and other hardware than
what is shown in this Chapter. It’s best to note
how the hardware is fitted on the vehicle
before dismantling, so you can duplicate it on
reassembly.
Braking system 9•3
3.5c Hold the guide pins while loosening
the caliper mounting bolts (3-Series)3.5b Unplug the electrical connector for
the brake pad wear sensor (3-Series)
3.5a On 3-Series models, unscrew the
caliper mounting bolts (left arrows); right
arrows point to the caliper bracket bolts,
which should only be removed if you’re
removing the brake disc
3.5f On 5-Series models, unplug the
electrical connector for the brake pad
wear sensor3.5e Remove the outer brake pad
(3-Series) - to fit the new pads, reverse the
removal procedure
3.5d Remove the caliper, brake pad wear
sensor and inner pad all at the same time
(3-Series), then refit the inner pad on the
piston and press the piston fully into the
bore with a C-clamp
9

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)

illustration). Use only low pressure, such as
that produced by a foot pump, to ease the
piston out of its bore.
Warning: Be careful not to place
your fingers between the piston
and the caliper, as the piston
may come out with some force. If
you’re working on a front caliper of a 3-
Series model, remove the dust boot.
6Inspect the mating surfaces of the piston
and caliper bore wall. If there is any scoring,
rust, pitting or bright areas, renew the
complete caliper unit.
7If these components are in good condition,
remove the piston seal from the caliper bore
using a wooden or plastic tool (see
illustration). Metal tools may damage the
cylinder bore.
8Remove the caliper guide pins or bolts and
remove the rubber dust boots.
9Wash all the components using methylated
spirit or brake system cleaner.
10Using the correct overhaul kit for your
vehicle, reassemble the caliper as follows.
11Dip the new rubber seal in clean brake
fluid, and refit it in the lower groove in the
caliper bore, making sure it isn’t twisted.
12On all calipers except the front calipers of
3-Series models, coat the walls of the caliperbore and the piston with clean brake fluid, and
refit the piston at this time. Do not force the
piston into the bore, but make sure that it is
squarely in place, then apply firm (but not
excessive) pressure to refit it. Fit the new
rubber dust boot and the retaining ring.
13On the front calipers of 3-Series models,
coat the piston with clean brake fluid, and
stretch the new dust boot over the bottom of
the piston. Hold the piston over the caliper
bore, and insert the rubber flange of the dust
boot into the upper groove in the bore. Start
with the furthest side from you, and work your
way around towards the front until it is
completely seated. Push the piston into the
caliper bore until it is bottomed in the bore,
then seat the top of the dust boot in the
groove in the piston.
14Lubricate the sliding surfaces of the guide
pins or bolts with silicone-based grease
(usually supplied in the kit), and push them
into the caliper. Refit the dust boots.
Refitting
15Refit the caliper by reversing the removal
procedure (see Section 3).
Warning: Check and if necessary
renew the mounting bolts on 3-
Series models whenever they are
removed. If in doubt, use new bolts.16If the hose was disconnected from the
caliper, bleed the brake system (see Sec-
tion 16).
5 Brake disc- inspection,
removal and refitting
2
Note:This procedure applies to both the front
and rear brake discs. Brake discs should
always be renewed or refinished in pairs (both
front or both rear discs) even if only one is
damaged or defective.
Braking system 9•5
4.4b Remove the circlip for the dust seal
4.4a An exploded view of a typical rear caliper assembly (front calipers similar)
4.7 Remove the piston seal from the
caliper bore using a wooden or plastic tool
(metal tools may damage the
cylinder bore)
1 Caliper assembly
2 Bracket mounting bolt
3 Bleed screw
4 Dust cap
5 Anti-rattle spring
6 Guide bolt
7 Brake pad wear warning
light wire8 Cable clamp
9 Brake disc
10 Allen bolt
11 Shield
12 Bolt
13 Washer
14 Plug15 Plug
16 Caliper bracket
17 Cable clamp
18 Piston seal, piston, dust
boot and circlip
19 Guide bush repair kit
20 Brake pads4.5 With the caliper padded to catch the
piston, use low pressure compressed air
to force the piston out of its bore - make
sure your fingers are not between the
piston and the caliper
9