1983 FIAT UNO wheel bolts

Vacuum servo unit and master
cylinder - general
54Access to the vacuum servo unit and the
master cylinder can only be obtained after the
cooling system expansion tank has been
released and moved aside (photo).
Antiskid system - description
55This system is available as an option on
the Turbo ie models only.
56The purpose of the system is to prevent
the wheel(s) locking during heavy brake
applications. This is achieved by automatic
release of the brake on a roadwheel which is
about to lock up, after which the brake is
re-applied. This cycle is carried out many
times per second under heavy braking,
retaining full steering control to avoid any
hazards.
57The main components of the system are
shown in Fig. 13.102. The control module
processes the signals received from the
sensors, and compares them with
deceleration values of the roadwheel and the
slip values of the tyre, which are stored in the
module memory.
58When reference values are exceeded and
wheel lock is imminent, the control module
signals the pressure modulators, which in turn
decrease the brake hydraulic pressure.
59Vehicle road speeds are also taken into
account by the module’s electronic circuits.
60In order to retain optimum system
performance, the tyres and wheels shouldalways be of the type originally fitted by the
vehicle manufacturer.
61Maintenance of the system should be
limited to checking the security of all electrical
and hydraulic connections. Individual compo-
nents are not repairable, and must be
renewed complete if faulty.15 Electrical system
Alternator (999 and
1108 cc models) -
removal and refitting
Á
1To remove the alternator from 999 cc
engine models, disconnect the leads from the
terminals on its rear face.
2Extract the screws and remove the plastic
drivebelt guard.
3Slacken the mounting and adjuster bolts,
push the alternator in towards the engine and
remove the drivebelt.
4Remove the mounting and adjuster bolts,
and withdraw the alternator downwards
through the gap between the right-hand
driveshaft and the engine sump pan (photo).
5Refitting is a reversal of removal; re-tension
the drivebelt.
Alternator (later models) -
removal and refitting Á
6Disconnect the battery negative lead.
7Loosen off the right-hand front roadwheelbolts, then raise and support the car at the
front end on axle stands. Remove the
right-hand roadwheel.
8Remove the wheel arch underwing shield
by driving the compression pins from the
centre of the retaining clips (using a 2 mm
drift), then prise free the panel retaining clips
and remove the shield. Keep the pins and
clips in a safe place and renew any that may
have been damaged during removal (photo).
9Detach the wiring connector from the
alternator.
10Release the alternator mounting and belt
adjuster link bolts, and take off the drivebelt.
11Take out the alternator top and bottom
mounting bolts.
Supplement: Revisions and information on later models 13•103
15.4 Removing the alternator from the
999 cc engine
Fig. 13.102 Braking system on Turbo ie Antiskid models (Sec 14)
13
1 Electronic control unit
(ECU)
2 Roadwheel speed
sensors
3 Pressure modulators
4 Vacuum reservoir
5 Check valve
6 Air cleaner
7 Load proportioning
(pressure regulating)
valves
8 Vacuum switch
9 ECU relay
10 System fault warning
lamp relay
11 System fault warning
lamp
12 Brake stop lamp
switch

15.23A Starter motor removal from the
1301 cc Turbo ie engine15.20 Starter motor removal from the
999 cc engine
12Disconnect the air cooling hose from the
rear cover of the alternator, and then unscrew
the fixing nuts and take off the rear cover with
hose spout. Mark the position of the cover on
the alternator before removing it, so that the
spout will be correctly positioned when
refitted (photos).
13Unbolt the driveshaft bearing
support/alternator bracket from the engine
crankcase, and swivel the support
downwards to provide space for withdrawal of
the alternator (photo).
14Withdraw the alternator from under the
right-hand front wing (photo).
15Refit in the reverse order of removal. Refit
the drivebelt and ensure correct engagement
with the pulleys, then set the drivebelt tension
and tighten the alternator retaining nuts.Alternator brushes -
renewal#
16Depending on model, the brush holder is
secured by two screws, which should be ex-
tracted and the brush holder removed (photos).
17New brushes and the holder are supplied
as an assembly.
Starter motor
(999 cc models) -
removal and refitting
Á
18To remove the starter motor from 999 and
1108 cc models, first disconnect the leads
from the starter motor terminals.
19Release the washer fluid reservoir flexible
bag from the engine compartment rear
bulkhead and move it to the left-hand side.
20Unscrew the starter motor mountingbolts, withdraw the starter from the flywheel
bellhousing, and then lift it out of the left-hand
side of the engine compartment (photo).
21Refitting is a reversal of removal.
Starter motor (1301 cc Turbo ie,
1372 cc ie,
1372 cc Turbo ie) -
removal and refitting
Á
22Disconnect the battery. Working from
under the front end of the car, unscrew the
starter motor mounting bolts and disconnect
the electrical leads.
23Withdraw the starter motor downwards. On
Turbo models, there is just enough clearance, if
the oil cooler hose and the oil pressure switch
lead are deflected carefully aside (photos).
24Refit by reversing the removal operations.
13•104 Supplement: Revisions and information on later models
15.16B Removing the alternator brush
holder
15.16A Extracting the alternator brush
holder screw15.14 Withdrawing the alternator15.13 Driveshaft bracket swivelled
downwards
15.12B Alternator rear cover and fixing nut15.12A Alternator air cooling hose15.8 Remove the wheel arch lower guard
panel for access to the alternator

adjustment procedures are the same as those
outlined for the previous model units in
Chapter 9, but ensure that the load
compensation lever is turned to the “O”
(normal load setting) position before making
any adjustments.
Headlamp unit removal - later
models
32The removal and refitting procedures
described in Chapter 9 also apply to the later
headlamp type, but note that later units are
secured in position by three retaining screws.
Headlamp dim-dip system -
description
33On later models, the wiring circuit has
been modified to prevent the car being drivenon parking lamps only in built-up areas.
34Headlamp intensity is reduced by the
transformer located at the front of the engine
compartment (photo).
35Any attempt to start the car with parking
lamps only on will automatically cause the
headlamps to switch on with a low-intensity
dipped beam. Dipped and main beam
function normally.
36The headlamp dim-dip system is a legal
requirement for all UK models registered after
April 1st, 1987.
Front fog lamps - bulb/unit
removal and refitting
and beam adjustment
ª
37Ensure that the front fog lamps are
switched off, then unscrew the two retainingscrews and withdraw the lamp unit from the
underside of the front bumper (photos).
38Undo the retaining screw and remove the
access cover from the unit (photo).
39Disconnect the wiring connector from the
bulb, release the clips and withdraw the bulb
from the lamp (photo).
40Refit in the reverse order of removal.
Check the light for satisfactory operation and
if the beam requires resetting, turn the
adjustment screw in the required direction.
41To adjust the beam, position the car 5 m
from, and square on to, a wall or similar.
42Measure the height of the centre of the
lamp lens from the ground and mark the
position on the wall. Switch on the lamp. The
demarcation line (cut-off) of the light should
be below the mark on the wall by 50 mm plus
one-third of the ground-to-lamp centre
measurement. Adjust the beam as required
using the long centre screw.
Horn - relocation
43The single horn, on applicable models, is
now located behind the grille, bolted on a
bracket attached to the top rail (photo).
Steering column combination
switches (later models) -
removal and refitting
Á
44Disconnect the battery negative lead.
45Undo the retaining screws and remove
the steering column shrouds (photos).
46Remove the steering wheel as described
in Chapter 10.
13•106 Supplement: Revisions and information on later models
15.45B . . . then remove the upper . . .15.45A Undo the retaining screws . . .15.43 Horn location
15.39 . . . detach the wires, extract the bulb15.38 . . . remove the rear cover . . .
15.37B . . . and withdraw the front fog lamp
unit . . .15.37A Undo the retaining bolts . . .15.34 Headlamp dim-dip transformer

Door closure sensor
117The sensor consists of a microswitch
within the lock. The switch actuates the
warning lamp according to whether the lock is
in the open or closed mode.
Check control system sensors -
testing
Brake fluid level sensor
118With the fluid level correct, switch on the
ignition and depress the centre of the
reservoir cap. If the sensor switches are
working correctly, then “FAULT” should be
indicated on the check panel.
Coolant level sensor
119With the coolant level in the expansion
tank correct, switch on the ignition and then
pull the wiring plug from the sensor. “FAULT”
should be indicated on the check panel. If it is
not, then it is the panel which is faulty.
120An ohmmeter should be used to check
for continuity, holding the float in both the full
and low level positions.
Engine oil level sensor
121With the oil level correct, disconnect the
wiring plug from the dipstick, and then bridge
the plug terminals (not dipstick side) with a 12
ohm resistor. Switch on the ignition.
122If the red light on the check panel goes
out, then the fault is due to the sensor.
123If the light stays on, then it is the check
panel module which is faulty.
Door closure sensor
124Any fault in the lock microswitch can best
be detected using an ohmmeter.
16 Suspension
Front anti-roll bar -
removal and refittingª
1A front anti-roll bar is fitted to the 1301 cc,
1372 cc ie and 1372 cc Turbo ie engined
models. Removal of the bar on all models isas follows. Firstly loosen off the front
roadwheel bolts, then raise the front of the
car, securely support it on axle stands and
remove the front roadwheels.
2Disconnect the two gearchange rods from
the transmission.
3Unbolt and disconnect the anti-roll bar
insulating clamps from the floorpan (photo).
4Unbolt the end links from the track control
arms and withdraw the anti-roll bar (photo).
5Refitting is a reversal of removal, but only
tighten the nuts and bolts to the specified
torque with the car parked on level ground,
with four passengers and 40 kg of luggage
inside.
Suspension strut - later models
6The suspension strut upper mounting nuts
on later models also secure the brackets for
the mounting of ancillary components such as
the fuel filter, fuel system relays and fuses,
etc. (depending on model).
7When removing the suspension strut units,
it will therefore be necessary to detach and
support these brackets and their fittings
(photo).
17 Bodywork
Plastic components
1With the use of more and more plastic
body components by the vehicle
manufacturers (e.g. bumpers, spoilers, and in
some cases major body panels), rectification
of more serious damage to such items has
become a matter of either entrusting repair
work to a specialist in this field, or renewing
complete components. Repair of such
damage by the DIY owner is not really
feasible owing to the cost of the equipment
and materials required for effecting such
repairs. The basic technique involves making
a groove along the line of the crack in the
plastic using a rotary burr in a power drill. The
damaged part is then welded back togetherby using a hot air gun to heat up and fuse a
plastic filler rod into the groove. Any excess
plastic is then removed and the area rubbed
down to a smooth finish. It is important that a
filler rod of the correct plastic is used, as
body components can be made of a variety
of different types (e.g. polycarbonate, ABS,
polypropylene). Damage of a less serious
nature (abrasions, minor cracks, etc.) can be
repaired by the DIY owner using a two-part
epoxy filler repair material. Once mixed in
equal proportions, this is used in similar
fashion to the bodywork filler used on metal
panels. The filler is usually cured in twenty to
thirty minutes, ready for sanding and
painting.
2If the owner is renewing a complete
component himself, or if he has repaired it
with epoxy filler, he will be left with the
problem of finding a suitable paint for
finishing which is compatible with the type of
plastic used. At one time the use of a
universal paint was not possible owing to the
complex range of plastics encountered in
body component applications. Standard
paints, generally speaking, will not bond to
plastic or rubber satisfactorily. However, it is
now possible to obtain a plastic body parts
finishing kit which consists of a pre-primer
treatment, a primer and coloured top coat.
Full instructions are normally supplied with a
kit, but basically the method of use is to first
apply the pre-primer to the component
concerned and allow it to dry for up to
30 minutes. Then the primer is applied and
left to dry for about an hour before finally
applying the special coloured top coat. The
result is a correctly coloured component
where the paint will flex with the plastic or
rubber, a property that standard paint does
not normally possess.
Rear view mirrors Á
Interior
3The mirror is of safety type, “breaking” off
its ball fixing upon impact from a front seat
occupant.
4To remove the mirror, grip the head and
Supplement: Revisions and information on later models 13•111
16.7 Suspension strut upper mounting
nuts, showing bracket and cable clip on
the 1372 cc ie model16.4 Anti-roll bar fixing nuts (arrowed)16.3 Anti-roll bar clamp
13

Engine fails to turn when starter
operated
m mFlat battery (recharge use jump leads or
push start)
m mBattery terminals loose or corroded
m mBattery earth to body defective
m mEngine earth strap loose or broken
m mStarter motor (or solenoid) wiring loose or
broken
m mIgnition/starter switch faulty
m mMajor mechanical failure (seizure)
m mStarter or solenoid internal fault (see
Chapter 12)
Starter motor turns engine slowly
m mPartially discharged battery (recharge, use
jump leads, or push start)
m mBattery terminals loose or corroded
m mBattery earth to body defective
m mEngine earth strap loose m mStarter motor (or solenoid) wiring loose
m mStarter motor internal fault (see Chapter 9)
Starter motor spins without
turning engine
m mFlywheel gear teeth damaged or worn
m mStarter motor mounting bolts loose
Engine turns normally but fails to
start
m mDamp or dirty HT leads and distributor cap
(crank engine and check for spark)
m mNo fuel in tank (check for delivery at
carburettor) m mExcessive choke (hot engine) or insufficient
choke (cold engine)
m mFouled or incorrectly gapped spark plugs
(remove, clean and regap)
m mOther ignition system fault (see Chapter 4)
m mOther fuel system fault (see Chapter 3)
m mPoor compression (see Chapter 1)
m mMajor mechanical failure (eg camshaft drive)
Engine fires but will not run
m
mInsufficient choke (cold engine)
m mAir leaks at carburettor or inlet manifold
m mFuel starvation (see Chapter 3)
m mIgnition fault (see Chapter 4)
Engine will not start
REF•10Fault Finding
Spares and tool kit
Most vehicles are supplied only with
sufficient tools for wheel changing; the
Maintenance and minor repairtool kit detailed
in Tools and working facilities,with the
addition of a hammer, is probably sufficient
for those repairs that most motorists would
consider attempting at the roadside. In
addition a few items which can be fitted
without too much trouble in the event of a
breakdown should be carried. Experience and
available space will modify the list below, but
the following may save having to call on
professional assistance:
m mSpark plugs, clean and correctly gapped
m mHT lead and plug cap – long enough to
reach the plug furthest from the distributor
m mDistributor rotor, condenser and contact
breaker points (where applicable)m mDrivebelt(s) — emergency type may
suffice
m mSpare fuses
m mSet of principal light bulbs
m mTin of radiator sealer and hose bandage
m mExhaust bandage
m mRoll of insulating tape
m mLength of soft iron wire
m mLength of electrical flex
m mTorch or inspection lamp (can double as
test lamp)
m mBattery jump leads
m mTow-rope
m mIgnition waterproofing aerosol
m mLitre of engine oil
m mSealed can of hydraulic fluid
m mEmergency windscreen
m mWormdrive clips
m mTube of filler pasteIf spare fuel is carried, a can designed for
the purpose should be used to minimise risks
of leakage and collision damage. A first aid kit
and a warning triangle, whilst not at present
compulsory in the UK, are obviously sensible
items to carry in addition to the above. When
touring abroad it may be advisable to carry
additional spares which, even if you cannot fit
them yourself, could save having to wait while
parts are obtained. The items below may be
worth considering:
m mClutch and throttle cables
m mCylinder head gasket
m mAlternator brushes
m mTyre valve core
One of the motoring organisations will be
able to advise on availability of fuel, etc, in
foreign countries.
A simple test lamp is useful for checking
electrical faultsCarrying a few spares may save you a long walk!

Glossary of Technical TermsREF•13
REF
A
ABS (Anti-lock brake system)A system,
usually electronically controlled, that senses
incipient wheel lockup during braking and
relieves hydraulic pressure at wheels that are
about to skid.
Air bag An inflatable bag hidden in the
steering wheel (driver’s side) or the dash or
glovebox (passenger side). In a head-on
collision, the bags inflate, preventing the
driver and front passenger from being thrown
forward into the steering wheel or windscreen.
Air cleanerA metal or plastic housing,
containing a filter element, which removes
dust and dirt from the air being drawn into the
engine.
Air filter elementThe actual filter in an air
cleaner system, usually manufactured from
pleated paper and requiring renewal at regular
intervals.
Allen keyA hexagonal wrench which fits into
a recessed hexagonal hole.
Alligator clipA long-nosed spring-loaded
metal clip with meshing teeth. Used to make
temporary electrical connections.
AlternatorA component in the electrical
system which converts mechanical energy
from a drivebelt into electrical energy to
charge the battery and to operate the starting
system, ignition system and electrical
accessories.
Ampere (amp)A unit of measurement for the
flow of electric current. One amp is the
amount of current produced by one volt
acting through a resistance of one ohm.
Anaerobic sealerA substance used to
prevent bolts and screws from loosening.
Anaerobic means that it does not require
oxygen for activation. The Loctite brand is
widely used.
AntifreezeA substance (usually ethylene
glycol) mixed with water, and added to a
vehicle’s cooling system, to prevent freezing
of the coolant in winter. Antifreeze also
contains chemicals to inhibit corrosion and
the formation of rust and other deposits that
would tend to clog the radiator and coolant
passages and reduce cooling efficiency.
Anti-seize compoundA coating that
reduces the risk of seizing on fasteners that
are subjected to high temperatures, such as
exhaust manifold bolts and nuts.
AsbestosA natural fibrous mineral with great
heat resistance, commonly used in the
composition of brake friction materials.Asbestos is a health hazard and the dust
created by brake systems should never be
inhaled or ingested.
AxleA shaft on which a wheel revolves, or
which revolves with a wheel. Also, a solid
beam that connects the two wheels at one
end of the vehicle. An axle which also
transmits power to the wheels is known as a
live axle.
AxleshaftA single rotating shaft, on either
side of the differential, which delivers power
from the final drive assembly to the drive
wheels. Also called a driveshaft or a halfshaft.
BBall bearingAn anti-friction bearing
consisting of a hardened inner and outer race
with hardened steel balls between two races.
BearingThe curved surface on a shaft or in a
bore, or the part assembled into either, that
permits relative motion between them with
minimum wear and friction.
Big-end bearingThe bearing in the end of
the connecting rod that’s attached to the
crankshaft.
Bleed nippleA valve on a brake wheel
cylinder, caliper or other hydraulic component
that is opened to purge the hydraulic system
of air. Also called a bleed screw.
Brake bleedingProcedure for removing air
from lines of a hydraulic brake system.
Brake discThe component of a disc brake
that rotates with the wheels.Brake drumThe component of a drum brake
that rotates with the wheels.
Brake liningsThe friction material which
contacts the brake disc or drum to retard the
vehicle’s speed. The linings are bonded or
riveted to the brake pads or shoes.
Brake padsThe replaceable friction pads
that pinch the brake disc when the brakes are
applied. Brake pads consist of a friction
material bonded or riveted to a rigid backing
plate.
Brake shoeThe crescent-shaped carrier to
which the brake linings are mounted and
which forces the lining against the rotating
drum during braking.
Braking systemsFor more information on
braking systems, consult the Haynes
Automotive Brake Manual.
Breaker barA long socket wrench handle
providing greater leverage.
BulkheadThe insulated partition between
the engine and the passenger compartment.
CCaliperThe non-rotating part of a disc-brake
assembly that straddles the disc and carries
the brake pads. The caliper also contains the
hydraulic components that cause the pads to
pinch the disc when the brakes are applied. A
caliper is also a measuring tool that can be set
to measure inside or outside dimensions of an
object.
CamshaftA rotating shaft on which a series
of cam lobes operate the valve mechanisms.
The camshaft may be driven by gears, by
sprockets and chain or by sprockets and a
belt.
CanisterA container in an evaporative
emission control system; contains activated
charcoal granules to trap vapours from the
fuel system.
CarburettorA device which mixes fuel with
air in the proper proportions to provide a
desired power output from a spark ignition
internal combustion engine.
CastellatedResembling the parapets along
the top of a castle wall. For example, a
castellated balljoint stud nut.
CastorIn wheel alignment, the backward or
forward tilt of the steering axis. Castor is
positive when the steering axis is inclined
rearward at the top.
Canister
Brake bleeding
Bearing
Air filter