fuel FIAT UNO 1983 Service Owner's Guide

pump jet and give ten full strokes of the
throttle lever, pausing between each stroke to
allow fuel to finish dripping.
8The total volume of fuel collected should be
between 2.5 and 4.5 cc. Adjust the nut on the
pump control and if necessary to increase or
decrease the volume of fuel ejected.
Fast idle adjustment
9With the choke valve plate fully closed, the
throttle valve plate should be open to give a
dimension (X) (Fig. 3.18) of between 0.90 and
1.0 mm (0.035 to 0.039 in). Use a twist drill of
suitable diameter to measure the gap. If
necessary, adjust by means of the screw and
locknut.
Anti-flooding device
10Close the choke valve plate by means of
the control lever. At the same time, push the
lean out valve rod towards the valve.
11There should be a gap (X) (Fig. 3.19)
between the edge of the choke valve plateand the carburettor throat of between 4.75
and 5.25 mm (0.187 to 0.207 in). Adjust if
necessary by means of the screw and locknut
on the lean out valve.
11 Carburettors (Weber 32 ICEE/
250 and Solex C32 DISA 14)-
description and adjustment
4
1One of these carburettors is used on
903 cc ES engines. They are very similar to
the Weber 32 ICEV 50/250 and Solex
C32 DISA 11 already described in this
Chapter except that a fuel cut-out solenoid
valve is fitted in association with the Digiplex
ignition system (see Chapters 4 and 9).
2The solenoid valve cuts off the supply of
fuel to the carburettor whenever the
accelerator pedal is released during overrun
conditions.
3A fuel cut-out device control unit receives
information regarding engine speed from the
static ignition control unit.
4A throttle butterfly switch relays informationthat the accelerator pedal is in the released
state.
5At certain minimum idle speeds during
deceleration, the fuel cut-out solenoid valve is
re-energised so that engine idling is
maintained without the tendency to cut out.
6The Solex type control unit varies the fuel
cut-out point according to the deceleration
value.Fault testing
7Should a fault develop, connect a test lamp
between the fuel cut-out solenoid switch and
a good earth.
8Connect a reliable tachometer to the engine
in accordance with the maker’s instructions.
9Start the engine and raise its speed to
between 3000 and 4000 rev/min, then fully
release the accelerator pedal.
10The test lamp should only go out during
the period when the accelerator pedal is
released. Should the test lamp remain on all
the time, or never come on, check the throttle
switch earth and the solenoid switch
connections.
11Disconnect the multi-plug from the control
unit. Switch on the ignition and check that a
test lamp connected between contact 7 of the
multi-plug and earth will illuminate. If it does
not, there is an open circuit from connection
15/54 of the fuel cut-off switch.
12Switch off the ignition and check for
continuity between contact 3 of the multiplug
and earth. An ohmmeter will be required for
this test.
13If there is no continuity (ohmmeter shows
infinity), check all the system earth
connections. Also check that the wiring plug
under the control unit is properly connected.
14Finally, check the engine speed signal. To
do this, a tachometer must be connected to
the single socket under the control unit within
the engine compartment.
15If the tachometer registers correctly then
this confirms that the electronic ignition
Fuel system 3•9
Fig. 3.18 Fast idle adjustment diagram (Solex C32 DISA 11)
(Sec 10)
X = 0.90 to 1.0 mm (0.035 to 0.039 in)Fig. 3.19 Anti-flooding device adjustment diagram
(Solex C32 DISA 11) (Sec 10)
X = 4.75 to 5.25 mm (0.187 to 0.207 in)
Fig. 3.21 Sectional view of fuel cut-off
switch (Solex C32 DISA 14) (Sec 11)
Fig. 3.20 Moving lean out valve rod
(Solex C32 DISA 11) (Sec 10)
X = 4.75 to 5.25 mm (0.187 to 0.207 in)
3

control unit is functioning, if the tachometer
does not register, renew the ignition control
unit.
16If a replacement carburettor is to be fitted,
only fit the Solex assembly including the
control module, even if a Weber was originally
fitted.
12 Carburettor
(Weber 32 ICEV 51/250)-
servicing and adjustment
4
1This carburettor, fitted to 1116 cc engines,
is very similar to the unit described in Sec-
tion 9.
2The fast idle adjustment procedure is
identical, but note that dimension (A) (Fig.
3.12) should be between 0.85 and 0.90 mm
(0.033 and 0.035 in).
3The choke valve plate gap (Y) (Fig. 3.13)
should be between 5.5 and 6.5 mm (0.22 and
0.26 in) and if adjustment is required, bend
the stop on the control lever.
13 Carburettor
(Solex C32 DISA 12)-
servicing and adjustment
4
1This carburettor is an alternative to the
Weber fitted to 1116 cc engines.
2The adjustments described in Section 9
apply.
14 Carburettor
(Weber 30/32 DMTR 90/250)
- servicing and adjustment
4
1The carburettor top cover with float may be
removed without the need to withdraw the
carburettor from the manifold. The other
adjustments described in this Section will
require removal of the carburettor.
2Extract the top cover fixing screws and lift
away the top cover with float. Access to the
fuel inlet needle valve is as described in
Section 9 paragraphs 4 and 5.
Float adjustment
3Hold the cover vertically so that the floats
hang down under their own weight. Measure
the distance between the float and the surface
of the gasket on the top cover. This should be
between 6.75 and 7.25 mm (0.27 and 0.29 in).
4Bend the float arm if necessary to adjust
the setting.
Primary valve plate opening
5With the throttle valve plate control lever in
contact with the stop, the primary valve plate
should be open (dimension X Fig. 3.22)
between 6.45 and 6.95 mm (0.25 and 0.27 in).
If adjustment is required, carefully bend the
lever stop.
Primary and secondary valve
plate openings
6With the throttle control lever fully actuated
the valve plate gaps (X and Y Fig. 3.24) should
be:
X = 13.5 to 14.5 mm (0.53 to 0.57 in)
Y = 14.5 to 15.5 mm (0.57 to 0.61 in)
Fast idle
7Close the choke valve plate fully and check
the gap (A) (Fig. 3.25) between the edge of the
throttle valve plate and the carburettor throat.
The gap should be between 0.90 and
0.95 mm (0.035 and 0.037 in), a twist drill is
useful for measuring this.
8If adjustment is required, carry this out
using the screw and locknut.
Anti-flooding device
(mechanically-operated)
9With the choke control pulled fully out, it
should be possible to open the choke valve
plate to give a gap (X) of between 7.0 and
7.5 mm (0.28 and 0.30 in). If adjustment is
required, carefully bend the stop on the
control lever (Fig. 3.26).
3•10 Fuel system
Fig. 3.26 Anti-flooding device (mechanical)
adjustment diagram
(Weber 30/32 DMTR 90/250) (Sec 14)
X = 7.0 to 7.5 mm (0.28 to 0.30 in)Fig. 3.25 Fast idle adjustment diagram
(Weber 30/32 DMTR 90/250) (Sec 14)
A = 0.90 to 0.95 mm (0.035 to 0.037 in)
Fig. 3.24 Throttle valve plate openings
(Weber 30/32 DMTR 90/250) (Sec 14)
X (primary) = 13.5 to 14.5 mm (0.53 to 0.57 in)
Y (secondary) = 14.5 to 15.5 mm (0.57 to 0.61 in)Fig. 3.23 Bending throttle lever stop
(Weber 30/32 DMTR 90/250) (Sec 14)Fig. 3.22 Primary valve plate opening
(Weber 30/32 DMTR 90/250) (Sec 14)
X = 6.45 to 6.95 mm (0.25 to 0.27 in)

Anti-flooding device (automatic)
10Pull the choke control fully out and hold the
control lever, on the anti-flooding device,
depressed. There should be a gap (Y)
(Fig. 3.27) between the edge of the choke valve
plate and the carburettor wall of between 3.75
and 4.25 mm (0.15 and 0.17 in). If adjustment is
required, turn the adjuster screw provided.
15 Carburettor
(Solex C30-32 (CIC/1)-
servicing and adjustment
4
1The carburettor top cover with float may be
removed without the need to withdraw the
carburettor from the manifold.
2The other adjustments described in this
Section will require removal of the carburettor.
3Extract the top cover fixing screws and lift
away the top cover with float.
4Refer to Section 9 paragraphs 4 and 5 for
details of removal of the fuel inlet needle
valve.
Float adjustment
5Invert the carburettor cover so that theweight of the floats depresses the ball of the
needle valve.
6Measure the distance between the float and
the surface of the cover gasket. This should
be between 6.5 and 7.5 mm (0.26 and 0.30 in).
If adjustment is required, change the
thickness of the needle valve washer or
carefully bend the float arm.
Accelerator pump
7Refer to Section 10, paragraphs 6 and 7.
The total volume of fuel collected should be
between 7.5 and 9.5 cc. If the volume of fuel
is incorrect, release the locknut and turn the
adjuster screw on the pump lever then re-test
the volume ejected.
Fast idle
8Operate the choke control lever to close the
choke valve plate. The gap between the edge
of the primary throttle valve plate and the
venturi wall should be between 0.90 and
1.00 mm (0.035 and 0.039 in). If adjustment is
required, turn the nut on the fast idle rod.
Automatic anti-flooding device
9The vacuum system of the device can be
checked for leaks by applying a vacuum to
the drilling in the carburettor throttle valve
block. If vacuum cannot be maintained, renew
the diaphragm.
Choke valve plate automatic
opening
10Move the choke control lever to fully close
the choke valve plate and then press the lean
out valve rod. There should now be a gap (X)
(Fig. 3.32) between the edge of the choke
valve plate and the wall of the carburettor
throat of between 4.75 and 5.25 mm (0.187
and 0.207 in).
11Where adjustment is required, release the
locknut and turn the screw on the lean out
valve.
16 Economy meter
1This device is fitted to ES (energy saving)
models. It is essentially a vacuum gauge to
advise the driver with regard to economical
throttle opening related to engine and road
speed. The point of change to a higher gear
can also be deduced from this gauge. The
latter facility is provided by an LED (light
emitting diode).
2Fault testing of the system is described in
Chapter 9.
Fuel system 3•11
Fig. 3.29 Adjusting accelerator pump
stroke (Solex C30-32 CIC/1) (Sec 15)Fig. 3.28 Float setting diagram
(Solex C30-32 CIC/1) (Sec 14)
A = 6.7 to 7.5 mm (0.26 to 0.30 in)
Fig. 3.32 Choke valve plate setting
(Solex C30-32 CIC/1) (Sec 15)
X = 4.75 to 5.25 mm (0.187 to 0.207 in)Fig. 3.30 Fast idle screw on
Solex C30-32 CIC/1 (Sec 15)
A Choke control lever C Lean out valve
B Fast idle adjustmentFig. 3.31 Vacuum drilling for automatic
anti-flooding device (Solex C30-32 CIC/1)
(Sec 15)
3
Fig. 3.27 Anti-flooding device (automatic)
adjustment diagram
(Weber 30/32 DMTR 90/250) (Sec 14)
Y = 3.75 to 4.25 mm (0.148 to 0.167 in)

19.7A Exhaust pipe support rings
17 Accelerator cable-
adjustment and renewal
2
1The socket type cable end fitting is
detached from the carburettor throttle lever
simply by prising it off the ball stud.
2Adjustment can be carried out by releasing
the locknut and turning the end fitting. With
the accelerator pedal fully depressed, check
that full throttle can be obtained at the
carburettor.
3To renew the cable, prise off the end fitting
from the carburettor throttle lever.
4Slip the cable sleeve from its retaining
bracket (photo).
5Working inside the car under the facia
panel, slip the cable from the fork at the top of
the accelerator pedal arm (photo). 6Withdraw the cable through the engine
compartment bulkhead.
7Fit the new cable by reversing the removal
operations, adjust as described in para-
graph 2.
18 Choke control cable-
removal and refitting
2
1Remove the air cleaner.
2Release the choke outer cable clamp and
the inner cable from the swivel on the choke
control lever (photo).
3The choke control is of lever type. To
remove it, extract its hinge screw, accessible
when the lever is pulled upwards (photo).
4Withdraw the choke cable assembly until
the inner cable can be released from the handcontrol lever and the choke warning lamp lead
unplugged.
5Withdraw the cable assembly through the
engine compartment rear bulkhead.
6Fit the new cable by reversing the removal
operations. Before tightening the inner cable
pinch screw at the carburettor, hold the choke
valve plate open and pull the control lever out
2.0 or 3.0 mm, then tighten the screw. This
will provide just enough free movement to
ensure that when the control is pushed fully in
the choke valve plate will remain fully open
even with engine movement slightly stretching
the cable.
19 Manifolds and exhaust
system
1
1The intake manifold on 903 cc engines is
integral with the cylinder head.
2On the other engines, the intake and
exhaust manifolds are mounted on the same
side of the cylinder head.
3A hot air collector plate is fitted over the
exhaust manifold from where the air cleaner
draws air when in the winter setting.
4When fitting a manifold, thoroughly clean
the cylinder head and manifold mating
surfaces, use a new gasket and tighten nuts
to the specified torque (photos).
5The exhaust system on 903 cc models is of
single downpipe, single silencer two section
type.
3•12 Fuel system
19.4C Fitting intake manifold complete
with carburettor19.4B Fitting exhaust manifold
19.4A Manifold gasket18.3 Extracting choke control lever screw
18.2 Choke cable at carburettor17.5 Accelerator pedal17.4 Throttle cable sleeve and bracket

6On 1116 cc and 1301 cc models, the
exhaust system is of dual downpipe, two
silencer, two section type.
7The exhaust system is flexibly mounted
(photo).
8Do not attempt to separate the sections ofthe exhaust system, while in position in the
car. Unbolt the pipe from the manifold and,
using a screwdriver, prise off the flexible
suspension rings. Provided the car is then
raised on jacks, ramps or placed over
an inspection pit, the complete exhaust system can be withdrawn from under the car.
9If only one section is to be renewed, it is far
easier to separate once the complete system
is out of the car.
10When refitting, grease the pipe sockets
and fit the clamps loosely until the suspension
rings are connected and the downpipe bolted
up (using a new copper gasket). Check the
attitude of the sections with regard to each
other and the adjacent parts of the
underbody. Fully tighten the clamps and
downpipe flange nuts, remembering to bend
up the lockplate tabs on 1116 cc and 1301 cc
models (photo).
11On the larger engined models, it may be
necessary to raise the vehicle at the rear and
support it on axle stands so that the rear sus-
pension hangs down and is fully extended.
This will allow sufficient clearance between
the axle and the body for the exhaust system
to be withdrawn.
Fuel system 3•13
3
19.10 Exhaust pipe socket clamp19.7B Exhaust tailpipe mounting
Fault finding - fuel system
Unsatisfactory engine performance and excessive fuel consumption
are not necessarily the fault of the fuel system or carburettor. In fact they
more commonly occur as a result of ignition and timing faults. Before
acting on the following it is necessary to check the ignition system first.
Even though a fault may lie in the fuel system it will be difficult to trace
unless the ignition is correct. The faults below, therefore, assume that
this has been attended to first (where appropriate).
Smell of petrol when engine is stopped
m mLeaking fuel lines or unions
m mLeaking fuel tank
Smell of petrol when engine is idling
m
mLeaking fuel line unions between pump and carburettor
m mOverflow of fuel from float chamber due to wrong level setting,
ineffective needle valve or punctured float
Excessive fuel consumption for reasons not
covered by leaks or float chamber faults
m mWorn jets
m mOver-rich setting
m mSticking mechanism
m mDirty air cleaner element
Difficult starting when cold
m
mChoke control
m mInsufficient use of manual choke
m mWeak mixture
Difficult starting, uneven running, lack of power,
cutting out
m mOne or more jets blocked or restricted
m mFloat chamber fuel level too low or needle valve sticking
m mFuel pump not delivering sufficient fuel
m mInduction leak
Difficult starting when hot
m
mExcessive use of manual choke
m mAccelerator pedal pumped before starting
m mVapour lock (especially in hot weather or at high altitude)
m mRich mixture
Engine does not respond properly to throttle
m
mFaulty accelerator pump
m mBlocked jet(s)
m mSlack in accelerator cable
Engine idle speed drops when hot
m
mIncorrect air cleaner intake setting
m mOverheated fuel pump
Engine runs on
m
mIdle speed too high

Spark plugs
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion RN9YCC or RN9YC
Electrode gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.8 mm (0.031 in)
HT leads
903 cc (45) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion LS-07
1116, 1299 and 1301 cc (55, 60 and 70) . . . . . . . . . . . . . . . . . . . . . . . . Champion LS-05
Torque wrench settingNm lbf ft
Spark plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 18
4•2 Ignition system
1 General description
On all models except the 903 ES engine
version, a mechanical contact breaker type
distributor is fitted.
On 45 Super ES models which have the
903 ES engine, an electronic (Digiplex) ignition
system is used which incorporates a
breakerless distributor.
Mechanical contact breaker
system
For the engine to run correctly, it is
necessary for an electrical spark to ignite the
fuel/air mixture in the combustion chamber at
exactly the right moment in relation to engine
speed and load. The ignition system is based
on feeding low tension voltage from the
battery to the coil where it is converted to high
tension voltage. The high tension voltage is
powerful enough to jump the spark plug gap
in the cylinders under high compression
pressures, providing that the system is in
good condition and that all adjustments are
correct.
The ignition system is divided into two
circuits, the low tension (LT) circuit and the
high tension (HT) circuit.
The low tension (sometimes known as the
primary) circuit consists of the battery, the
lead to the ignition switch, the lead from the
ignition switch to the low tension or primary
coil windings, and the lead from the low
tension coil windings to the contact breaker
points and condenser in the distributor.
The high tension circuit consists of the high
tension or secondary coil windings, the heavy
ignition lead from the centre of the coil to the
centre of the distributor cap, the rotor arm,
and the spark plug leads and spark plugs.
The system functions in the following
manner: High tension voltage is generated in
the coil by the interruption of the low tension
circuit. The interruption is effected by the
opening of the contact breaker points in this
low tension circuit. High tension voltage is fed
from the centre of the coil via the carbon
brush in the centre of the distributor cap to
the rotor arm of the distributor.
The rotor arm revolves at half engine speed
inside the distributor cap, and each time it
comes in line with one of the four metal
segments in the cap, which are connected to
the spark plug leads, the opening of thecontact breaker points causes the high
tension voltage to build up, jump the gap from
the rotor arm to the appropriate metal
segment, and so via the spark plug lead to the
spark plug, where it finally jumps the spark
plug gap before going to earth.
The ignition timing is advanced and
retarded automatically, to ensure the sparkoccurs at just the right instant for the
particular load at the prevailing engine speed.
The ignition advance is controlled
mechanically, and by vacuum. The
mechanical governor mechanism consists of
two weights, which move out from the
distributor shaft as the engine speed rises,
due to centrifugal force. As they move
Fig. 4.1 Typical ignition circuit (mechanical contact breaker distributor) (Sec 1)
1 Control unit
2 Multi-plug
3 Ignition coil
4 Distributor cap5 Crankshaft pulley
6 Flywheel
7 Battery
8 Rev counter9 Spark plugs
10 Wiring connector
S1 Engine speed sensor
S2 TDC sensor
Fig. 4.2 Digiplex electronic ignition system (Sec 1)

Fault finding - mechanical breaker ignition system
Ignition system 4•9
4
Engine fails to start
m mLoose battery connections
m mDischarged battery
m mOil in contact points
m mDisconnected ignition leads
m mFaulty condenser
Engine overheats, lacks power
m
mSeized distributor weights
m mPerforated vacuum pipe
m mIncorrect ignition timing
Engine starts and runs but misfires
m
mFaulty spark plug
m mCracked distributor cap
m mCracked rotor arm
m mWorn advance mechanism
m mIncorrect spark plug gap
m mIncorrect contact points gap
m mFaulty condenser
m mFaulty coil
m mIncorrect timing
m mPoor engine/transmission earth connections
Fault finding - Digiplex (electronic) ignition system
Engine fails to start
m
mExcessive gap on TDC sensor
m mTDC or engine speed sensor short circuited or earthed
m mDefective ignition control unit
m mControl unit multi-plug contacts corroded
m mDefective coil
Engine lacks power, high fuel consumption
m
mIncorrect ignition advance
m mTDC sensor incorrectly set
m mDistributor vacuum hose blocked

their originally fitted sequence and note in
which direction the seal lips are located.
11Inspect the surfaces of the piston and
cylinder bore. If scoring, corrosion or
metal-to-metal rubbing areas are evident,
renew the master cylinder complete.
12If the components are in good condition,
discard the oil seals and manipulate the new
ones into position, using the fingers only.
13Refit by reversing the removal operations;
apply pressure to the piston ends so that the
stop bolts can be fitted, then tighten the end
plug. Make sure that the grooves in the
pistons engage in the stop bolts.
14Before refitting the master cylinder to the
servo, measure the projection of the servo
piston pushrod. When the master cylinder is
fitted, there must be a clearance (see A in
Fig. 8.7) between the end of the pushrod and
the primary piston end face of between 0.825
and 1.025 mm (0.03 and 0.04 in). A depth
gauge will be required for these
measurements, the reference point being the
mating surfaces of the master cylinder and the
vacuum servo.
15Alter the adjusting screw on the servo as
necessary and lock it by applying locking fluid
to the threads on completion.16Bolt the master cylinder to the vacuum
servo or bulkhead, then reconnect the
pipelines and reservoir cap leads.
17Bleed the complete hydraulic system, as
described in Section 12.
10 Pressure regulating valve
3
1The pressure regulating valve is a load
proportioning valve which restricts the
hydraulic pressure to the rear brakes
according to car weight during heavy
applications of the brake pedal. This prevents
the rear wheels locking.
2A faulty or non-operational valve should be
renewed complete, no repair being possible.
3To remove the valve, unscrew the pipe
unions and disconnect the hydraulic pipes
from the valve. Cap the ends of the pipes to
prevent loss of fluid.
4Unbolt the valve mounting bracket,
withdraw it and disconnect the tension spring
(photo).
5Refit the new valve and then adjust it in the
following way.
6Have the car standing on a level floor.
7The car should be normally loaded (kerb
weight) with fuel, oil, spare wheel etc. Load
the luggage compartment immediately behind
the seat back with:
65 kg (143 lbs) on three-door models or 55 kg (121 lbs) on five-door models
8Refer to Fig. 8.10 and slacken the valve
bracket securing bolt (1).
9Attach a 6.0 kg (13.2 lb) weight to the
bracket eye (2) as shown and then tighten the
bracket securing bolt.
10Bleed the braking system if a new valve
has been fitted. Bleeding will not of course be
required if only adjustment has been carried
out to an existing valve.11 Hydraulic hoses and pipes-
inspection and renewal
3
Flexible hoses
1Periodically, all brake pipes, pipe
connections and unions should be completely
and carefully examined.
2First examine for signs of leakage where the
pipe unions occur. Then examine the flexible
hoses for signs of chafing and fraying and, of
course, leakage. This is only a preliminary part
of the flexible hose inspection, as exterior
condition does not necessarily indicate the
interior condition, which will be considered
later.
3Flexible hoses are always mounted at both
ends in a rigid bracket attached to the body or
a sub-assembly. To remove them, it is
necessary first of all to unscrew the pipe
unions of the rigid pipes which go into them.
8•6 Braking system
Fig. 8.11 Typical hydraulic hose connection
(Sec 11)
Fig. 8.10 Weight attachment point for
pressure regulating valve adjustment (Sec 10)
1 Fixing bolt 2 Bracket eye
Fig. 8.9 Components of the pressure
regulating valve (Sec 10)
Fig. 8.8 Pressure regulating valve (Sec 10)10.4 Pressure regulating valve bracket and
tension spring

locknut and turn the adjuster nut on the
handbrake primary rod (photo).
3Raise the rear roadwheels and check that
they turn freely when the handbrake lever is
fully released.
17 Handbrake cable-
renewal
1
1There are two cables, either of which may
be renewed independently
2Disconnect the cable, which is to be renewed,
from the shoe lever at the brake backplate.
3Disconnect the longer cable from the
primary link or rod and release the cable from
its retainers. On later models with a plastic
fuel tank, a cable bracket is moulded into the
side of the tank (photo).4Disconnect the shorter cable from the pivot
lever at the pulley on the rear axle (photo).
5Refit the new cables by reversing the
removal operations and then adjust as
described in the preceding Section.
18 Brake pedal-
removal and refitting
1
1The operations are described in
conjunction with the clutch pedal in Chapter
5, Section 4.
2The brake pedal pushrod will slide out of
the servo unit as the pedal is withdrawn.
19 Stop lamp switch
1
1The brake stop lamp switch is of plunger
type acting on the pedal arm.
2Adjust the position of the switch by turning
the locknuts until the stop lamps illuminate
when the pedal arm is depressed through 1.0
mm (0.039 in).
Braking system 8•9
Fig. 8.13 Handbrake components (Sec 17)
17.4 Handbrake cable pulley17.3 Handbrake cable guide on fuel tank
8
Fault finding - braking system
Excessive pedal travel
m mPads or shoes excessively worn
m mIncorrect pedal or servo pushrod adjustment
m mAutomatic adjusters faulty
m mSeized wheel cylinder or caliper piston
m mMaster cylinder seals worn
Pedal feels spongy or soggy
m
mAir in hydraulic system
m mLow fluid level
m mLoose connections
m mFlexible hose perished
m mDefective wheel cylinder or caliper seal
Pedal feels springy
m
mNew pads or linings not bedded-in
m mMaster cylinder mounting loose
Pedal vibrates when brakes applied
m
mDiscs or drums distorted
m mFriction linings excessively worn
m mLoose backplate or caliper mounting bolts
m mWear in steering or suspension components
Excessive effort required to stop car
m
mWorn or contaminated linings or pads
m mIncorrect grade of lining or pad material
m mServo vacuum hose leaking or disconnected
m mFaulty servo or non-return valve (55 or 70 models)
m mSeized caliper or wheel cylinder piston
m mOne circuit defective on dual circuit hydraulic system
Brakes pull to one side
m
mFriction linings contaminated on one side of car
m mSeized hydraulic piston on one side of car
m mDifferent types of linings fitted on different sides of car, or new
linings on one side only
m mSeized automatic adjuster on one side of car
Brakes drag
m
mHandbrake linkage overadjusted or seized
m mSeized caliper or wheel cylinder piston
Brakes squeal
m
mDrums or discs rusty or damp (temporary fault - no action
necessary)
m mDust or grit in brake drums
m mLinings excessively worn

8Withdraw the solenoid and yoke off the
armature and from the drive end bracket.
Note the steel and fibre washers and the
shims on the armature shaft (photo).
9Extract the split pin and tap out the
engagement lever pivot pin.
10Pull the rubber packing piece from the
drive end bracket.
11Withdraw the armature with solenoid
plunger, coil spring and engagement lever.
12Clean the commutator with a fuel soaked
rag or very fine glass paper. Do not undercut
the mica insulators on the commutator.
Drive
13To remove the drive assembly from the
armature shaft, use a piece of tubing to tap
the stop collar down the shaft to expose the
snap ring. Remove the snap ring and stop
collar and slide the drive assembly from the
shaft.
14Refitting is a reversal of removal, but use a
new snap ring to secure the drive to the
armature shaft.
10 Fuses and relays
1
1The fuse box is located under the left-hand
side of the facia panel and is held in place by
two hand screws (photo).2The fuses and the circuits protected are
identified by symbols. Refer also to Specifi-
cations.
3If a fuse blows, always renew it with one of
identical rating. If the new fuse blows
immediately, find the cause before renewing
the fuse for the second time. This is usually
due to defective wiring insulation causing a
short circuit.
4Never substitute a piece of wire or other
makeshift device for a proper fuse.
5Various relays are plugged into the fuse
block and include those for the heated rear
screen, heater and horns.
6On cars fitted with power-operated front
windows and centralised door locking, the
fuses and relays for these circuits are
mounted separately under the right-hand side
of the facia panel.
7The relay (flasher unit) for the direction
indicators and hazard warning lamps is
located on the lower part of the
steering column combination switch and
is accessible after removing the column
shroud.
11 Steering column
combination switch
1
1Disconnect the battery negative lead.
2Remove the steering column shrouds. 3The switch can be removed without
having to take off the steering wheel, but for
clarity, the photographs show the wheel
removed.
4Unscrew the switch clamp nuts, disconnect
the wiring plug and remove the switch from
the steering column (photo).
5Refitting is a reversal of removal, but make
sure that the activating projections on the
steering wheel hub engage correctly with the
switches.
12 Courtesy lamp switch
1
1These are located in and secured to the
body pillars with a single screw (photo).
2Disconnect the battery negative lead.
3Extract the switch screw and withdraw the
switch.
4If the leads are to be disconnected, tape
them to the pillar to prevent them from
slipping inside.
5Refitting is a reversal of removal. Apply
petroleum jelly to the switch contacts to
prevent corrosion.
13 Rocker and push-button
switches
1
1These are mounted in panels on each side
of the instrument panel.
2Disconnect the battery negative lead.
3Prise off the instrument panel hood cover.
This is held in place by clips. The careful use
of a screwdriver will assist in releasing them
(see Section 21).
4Extract the switch panel fixing screws.
These compress spring clips which in turn
secure the switch panel (photo).
5Withdraw the switch panel until the wiring
plugs can be disconnected. Record the
location of the plugs before disconnecting
Electrical system 9•5
11.4 Unscrewing steering column switch
clamp nut
1 Direction indicator flasher unit (relay)10.1 Fuse block (later models)
1 Horn relay
2 Heated tailgate window relay9.8 Starter motor dismantled
13.4 Switch panel screw12.1 Courtesy lamp switch
9