cooling FIAT UNO 1983 Service Repair Manual

REPAIRS & OVERHAUL
Engine and Associated Systems
Engine (also see Chapter 13)Page 1•1
Cooling and heating systems (also see Chapter 13)Page2•1
Fuel system (also see Chapter 13)Page 3•1
Ignition system (also see Chapter 13)Page4•1
Transmission
Clutch (also see Chapter 13)Page5•1
Transmission (also see Chapter 13)Page6•1
Driveshafts, hubs, roadwheels and tyres (also see Chapter 13)Page7•1
Brakes
Braking system(also see Chapter 13)Page 8•1
Electrical
Electrical system(also see Chapter 13)Page 9•1
Steering and suspension
SteeringPage 10•1
Suspension (also see Chapter 13)Page 11•1
Bodywork
Bodywork (also see Chapter 13)Page 12•1
Additional information
Supplement: Revisions and information on later models Page 13•1
Wiring DiagramsPage 14•1
REFERENCE
MOT Test Checks PageREF•1
Tools and Working Facilities Page REF•5
General Repair Procedures Page REF•8
Fault FindingPage REF•9
Buying Spare Parts & Vehicle Identification Numbers PageREF•12
Glossary of Technical Terms PageREF•13
IndexPage REF•17
Contents

0•6General dimensions, weights and capacities
Dimensions
Overall length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3644 mm (143.6 in)
Overall width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1555 mm (61.3 in)
Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1432 mm (56.4 in)
Wheelbase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2362 mm (93.1 in)
Front track . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1340 mm (52.8 in)
Rear track . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1300 mm (51.2 in)
Weights (kerb)
Uno 45:
Three-door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 700 kg (1543 lb)
Five-door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 710 kg (1566 lb)
Uno 55:
Three-door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 730 kg (1610 lb)
Five-door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 740 kg (1632 lb)
Uno 70:
Three-door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 740 kg (1632 lb)
Five-door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750 kg (1654 lb)
Uno SX:
Three-door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 770 kg (1698 lb)
Five-door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 780 kg (1720 lb)
Capacities
Fuel tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42.0 litre (9.25 gal)
Engine oil (with filter change):
903 cc engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.42 litre (6.0 pint)
1116 and 1301 cc engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.10 Iitre (7.2 pint)
Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.40 litre (4.2 pint)
Steering box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140.0 cc
Driveshaft CV joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125.0 cc
Cooling system:
903 cc engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6 litre (8.1 pint)
1116 cc engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0 litre (10.6 pint)
1301 cc engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 litre (10.9 pint)
For information applicable to later models, see Supplement at end of manual

Routine maintenance0•11
Engine compartment (air cleaner removed for clarity) on 55S model
1 Strut upper mounting
2 Washer fluid reservoir
3 Brake fluid reservoir
4 Ignition coil5 Throttle cable
6 Carburettor
7 Battery
8 Timing belt cover9 Distributor
10 Oil filler cap
11 Radiator electric cooling
fan12 Radiator
13 Coolant expansion tank
14 Front mounting
15 Clutch operating cable

Lubricants and Fluids0•13
Component or system Lubricant type/specification
1 EngineMultigrade engine oil, viscosity SAE 15W/40, meeting API-SG or CCMC
G2/G3 specification (or equivalent multigrade engine oil with viscosity
rating suitable for ambient temperature in which vehicle is operated -
see owner’s handbook)
2 Transmission:
1372 cc Turbo ie model FIAT ZC 80/S gear oil
All other models FIAT ZC 90 gear oil
3 Cooling systemEthylene glycol based antifreeze
4 Brake and clutch hydraulic system(s)Hydraulic fluid to DOT 3 or 4, or SAE J1703C
5 Driveshaft CV joints and steering rackLithium based molybdenum disulphide
General greasingMulti-purpose lithium based grease

13Engage the timing chain with the teeth of
the crankshaft sprocket. Then locate the
camshaft sprocket within the upper loop of
the chain in such a way that when the
sprocket is pushed onto the camshaft, the
timing marks will be in alignment. Make sure
that the self-tensioning links are on the inside
of the chain against the cylinder block
(photos).
14Place the camshaft sprocket onto the
camshaft so that its positioning dowel
engages.
15Secure the camshaft sprocket by fitting
the special cam, that drives the fuel pump, on
its locating dowel. Fit the camshaft sprocket
retaining bolt (photo).
16Tighten the sprocket bolt to the specified
torque.
17If the timing cover oil seal showed signs of
leaking before engine overhaul the old seal
should be removed and a new one fitted.
18Using a screwdriver, carefully remove the
old oil seal, working from the rear of the cover.
Fit the new seal making sure it is inserted
squarely, and tap home with a hammer.
19Lubricate the oil seal with engine oil.
20With all traces of old gasket and jointing
compound removed from the timing cover
and cylinder block mating faces, smear a little
grease onto the timing cover mating face and
fit a new gasket in position.
21Fit the timing cover to the cylinder block
and finger tighten the securing bolts, and
spring washer. Ensure that the fuel pump
pushrod bush is in place in the cover.22Wipe the hub of the pulley and carefully
place into position on the crankshaft. It should
locate on the Woodruff key. It may be
necessary to adjust the position of the timing
cover slightly in order to centralise the oil seal
relative to the pulley hub.
23Tighten the timing cover securing bolts in
a diagonal and progressive manner.
24Tighten the crankshaft pulley nut to the
specified torque again holding the crankshaft
against rotation as previously described
(paragraph 2) this Section.
25Refit the fuel pump and alternator
drivebelt.
7 Cylinder head-
removal and refitting
3
1For safety reasons, disconnect the battery
negative lead.
2Refer to Chapter 2 and drain the cooling
system.
3Refer to Chapter 3 and remove the
carburettor, air cleaner and spacer block.
4Undo and remove the five nuts and
washers securing the exhaust manifold and
hot air ducting to the cylinder head.
5Detach the cable from the temperature
indicator sender unit.
6Refer to Chapter 4 and disconnect the
distributor LT lead and the coil HT lead.
7Refer to Chapter 2 and remove the
thermostat housing from the cylinder head.
8Disconnect the coolant hoses from the
cylinder head.
9Note the electrical connections to the rear
of the alternator and disconnect them.
10Disconnect the mounting and adjuster link
bolts and remove the alternator from the
engine.
11Unscrew the four nuts securing the rocker
cover to the top of the cylinder head and lift
away the spring washers and metal packing
pieces. Remove the rocker cover and cork
gasket.
12Unscrew the four rocker pedestal
securing nuts in a progressive manner. Lift
away the four nuts and spring washers andease the valve rocker assembly from the
cylinder head studs.
13Remove the pushrods, keeping them in
the relative order in which they were removed.
The easiest way to do this is to push them
through a sheet of thick paper or thin card in
the correct sequence.
14Unscrew the cylinder head securing bolts
half a turn at a time in the reverse order to that
shown in Fig. 1.7; don’t forget the one within
the inlet manifold. When all the bolts are no
longer under tension they may be unscrewed
from the cylinder head one at a time. This will
also release a section of the cooling system
pipe secured by two of the bolts. All the bolts
have washers.
15The cylinder head may now be lifted off. If
the head is jammed, try to rock it to break the
seal. Under no circumstances try to prise it
apart from the cylinder block with a
screwdriver or cold chisel as damage may be
done to the faces of the head or block. If this
or the Hint, fail to work, strike the head
sharply with a plastic headed hammer, or with
a wooden hammer, or with a metal hammer
with an interposed piece of wood to cushion
the blows. Under no circumstances hit the
head directly with a metal hammer as this may
cause the casting to fracture. Several sharp
taps with the hammer, at the same time
pulling upwards, should free the head. Lift the
head off and place on one side.
16The cylinder head may now be de-
carbonised or dismantled, refer to Section 17.
Refitting
17After checking that both the cylinder block
and cylinder head mating surfaces are
perfectly clean, generously lubricate each
cylinder with engine oil.
18Always use a new cylinder head gasket as
the old gasket will be compressed and not
capable of giving a good seal.
1•10 903 cc engine
6.15 Fitting fuel pump drive cam and
sprocket bolt
6.13C Self-tensioning links on inside of
chain6.13B Timing mark alignment6.13A Fitting the sprockets and timing
chain
If the head will not readily
free, turn the crankshaft.
The compression generated
in the cylinders will often
break the gasket joint

19Never smear grease on the gasket as,
when the engine heats up, the grease will melt
and may allow compression leaks to develop.
20The cylinder head gasket cannot be fitted
incorrectly due to its asymmetrical shape, but
the word ALTO should be uppermost in any
event (photo).
21The locating dowels should be refitted to
the front right and left-hand side cylinder head
securing bolt holes.
22Carefully fit the cylinder head gasket to
the top of the cylinder block.
23Lower the cylinder head onto the gasket,
taking care not to move the position of the
gasket.
24Screw in the cylinder head bolts finger
tight, remembering the bolt within the intake
manifold and the metal coolant pipe which is
held by the two cylinder head bolts adjacent to
the coolant temperature sender unit (photos).
25Tighten the cylinder head bolts in two
stages, in the specified sequence to the
torque given in Specifications.
26With the cylinder head in position, fit the
pushrods in the same order in which they
were removed. Ensure that they locate
properly in the stems of the tappets and
lubricate the pushrod ends before fitment
(photo).
27Unscrew the rocker arm adjuster screws
as far as they will go.
28Fit the rocker gear over the four studs in
the cylinder head and lower onto the cylinder
head. Make sure the ball ends of the rockers
locate in the cups of the pushrods.29Fit the four nuts and washers to the rocker
shaft pedestal studs and tighten in a
progressive manner to the torque wrench
setting given in the Specifications.
30Adjust the valve clearances as described
in Section 5.
31Fit the exhaust manifold, thermostat
housing and alternator, also the rocker cover
(photo).
32Fit the carburettor, air cleaner and
distributor (Chapter 4).
33Reconnect all hoses and electrical leads,
including the battery.
34Refill the cooling system.
8 Sump pan-
removal and refitting
1
1Drain the engine oil.
2Unscrew and remove the four nuts and
twelve bolts and lift away the sump pan. If it
has stuck on the gasket carefully tap the side
of the mating flange to break the seal.
Remove the gasket and clean away any
pieces of gasket cement which are adhering
to the flanges.
3Remove the sealing strips from the
recesses at either end of the sump pan.
Refitting
4Fit the new sealing strips and if necessary,
trim their ends until they are just proud of the
sump pan flange (photo).5Using thick grease, stick the gasket side
strips to the crankcase.
6Apply a blob of jointing compound at the
points of overlap of the side gaskets and
strips.
7Offer up the sump pan, screw in and tighten
the bolts and nuts progressively (photos).
8Refill the engine with oil.
903 cc engine 1•11
7.24B Cylinder head bolts holding coolant
pipe7.24A Cylinder head bolt in intake manifold7.20 Cylinder head gasket
7.31 Fitting the rocker cover
7.26 Fitting a pushrod
Fig. 1.7 Cylinder head bolt tightening
sequence (Sec 7)1
8.4 Sump pan sealing strip8.7A Fitting the sump pan

24Screw in the big-end bolts and tighten to
the specified torque (photo).
25Refit the sump pan (Sec 8) and the
cylinder head (Sec 7).
26Refill the engine with oil and coolant.
10 Oil pump-
removal and refitting
1
1Remove the sump pan as described in
Section 8.
2Unscrew the two bolts which hold the oil
pump housing to the underside of the
crankcase and withdraw the pump. Remove
and discard the pump flange gasket.
Refitting
3Stick a new gasket to the oil pump location
on the underside of the crankcase (photo).
4Locate the oil pump driveshaft in the oil
pump and then offer up the complete
assembly to the crankcase so that the gear
teeth on the driveshaft mesh with those on the
camshaft (photo).
5Fit the securing bolts (photo).
6Fit the sump pan and refill the engine with
oil.
11 Engine mountings-
renewal
1
1The engine/transmission flexible mountings
can be removed if the power unit is supported
under the sump pan or gearbox with a jack, or
a hoist is attached to the engine lifting lugs
and the weight of the power unit just taken.
2Unscrew the mounting bracket bolts and
remove the mounting.
3Fit the new mounting and remove the lifting
gear.
4In the unlikely event of all the mountings
requiring renewal at the same time, renew
them one at a time, never disconnect all the
mountings together.
12 Engine- method of removal
1The engine/transmission should be
removed downwards and withdrawn from
under the front of the car which will have to be
raised sufficiently high to provide clearance.
13 Engine/transmission-
removal and separation
3
1Open the bonnet, disconnect the
windscreen washer tube.
2Mark the hinge positions on the underside
of the bonnet using masking tape and thenwith the help of an assistant to support its
weight unbolt the bonnet and remove it to a
safe place.
3Disconnect the battery negative lead.
4Drain the cooling system and engine oil.
5Disconnect the leads from the rear of the
alternator, the starter motor and the oil pressure
switch also the coolant temperature switch.
6Disconnect the HT lead from the ignition
coil and the LT lead from the distributor.
Disconnect the transmission earth strap.
7Remove the air cleaner.
8Disconnect the clutch cable from the
release lever at the transmission.
9Disconnect the speedometer drive cable by
unscrewing the knurled nut from the
transmission.
903 cc engine 1•13
10.3 Oil pump gasket
10.4 Fitting the oil pump10.5 Tightening an oil pump bolt
9.24 Tightening a big-end bolt
Fig. 1.11 Speedometer drive cable at
transmission (Sec 13)Fig. 1.10 Clutch cable disconnected (Sec 13)
C Reversing switch cablesFig. 1.9 Coolant temperature switch
(Sec 13)
1

light alloy construction and is easily damaged
use a blunt scraper or rotary wire brush to
clean all traces of carbon deposits from the
combustion spaces and the ports. The valve
head stems and valve guides should also be
freed from any carbon deposits. Wash the
combustion spaces and ports down with
paraffin and scrape the cylinder head surface
free of any foreign matter with the side of a
steel rule, or a similar article.
8If the engine is installed in the car, clean the
pistons and the top of the cylinder bores. If
the pistons are still in the block, then it is
essential that great care is taken to ensure
that no carbon gets into the cylinder bores as
this could scratch the cylinder walls or cause
damage to the piston and rings. To ensure
this does not happen, first turn the crankshaft
so that two of the pistons are at the top of
their bores. Stuff rag into the other two bores
or seal them off with paper and masking tape.
The waterways should also be covered with
small pieces of masking tape to prevent
particles of carbon entering the cooling
system and damaging the coolant pump.
9With a blunt scraper carefully scrape away
the carbon from the piston crown, taking care
not to scratch the aluminium. Also scrape
away the carbon from the surrounding lip of
the cylinder wall. When all carbon has been
removed, scrape away the grease which will
now be contaminated with carbon particles,
taking care not to press any into the bores. To
assist prevention of carbon build-up the
piston crown can be polished with a metal
polish. Remove the rags or masking tape from
the other two cylinders and turn the
crankshaft so that the two pistons which were
at the bottom are now at the top. Place rag in
the cylinders which have been decarbonised,
and proceed as just described.
10Examine the head of the valves for pitting
and burning, especially the heads of the
exhaust valves. The valve seatings should be
examined at the same time. If the pitting on
the valve and seat is very slight, the markscan be removed by grinding the seats and
valves together with coarse, and then fine,
valve grinding paste.
11Where bad pitting has occurred to the
valve seats it will be necessary to recut them
and fit new valves. This latter job should be
entrusted to the local agent or engineering
works. In practice it is very seldom that the
seats are so badly worn. Normally it is the
valve that is too badly worn for refitting, and
the owner can easily purchase a new set of
valves and match them to the seats by valve
grinding.
12Valve grinding is carried out as follows.
Smear a trace of coarse carborundum paste
on the seat face and apply a suction grinder
tool to the valve head. With a semi-rotary
motion, grind the valve head to its seat, lifting
the valve occasionally to redistribute the
grinding paste. When a dull matt even surface
is produced on both the valve seat and the
valve, wipe off the paste and repeat the
process with fine carborundum paste, lifting
and turning the valve to redistribute the paste
as before. A light spring placed under the
valve head will greatly ease this operation.
When a smooth unbroken ring of light grey
matt finish is produced, on both valve and
valve seat faces, the grinding operation is
complete. Carefully clean away every trace of
grinding compound, take great care to leave
none in the ports or in the valve guides. Clean
the valve seats with a paraffin soaked rag,
then with a clean rag, and finally, if an air line
is available, blow the valves, valve guides and
valve ports clean.
13Check that all valve springs are intact. If
any one is broken, all should be renewed.
Check the free height of the springs against
new ones. If some springs are not within
specifications, replace them all. Springs suffer
from fatigue and it is a good idea to renew
them even if they look serviceable.
14Check that the oil supply holes in the
rocker arms are clear.
15The cylinder head can be checked for
warping either by placing it on a piece of plate
glass or using a straight-edge and feeler
blades. If there is any doubt or if its block face
is corroded, have it re-faced by your dealer or
motor engineering works.
16Test the valves in their guides for side toside rock. If this is any more than almost
imperceptible, new guides must be fitted.
Again this is a job for your dealer as a special
tool is required to ensure the correct
installation depth and the cylinder head must
be warmed to 80ºC (176ºF) before fitting the
guides.
17Commence reassembly by oiling the stem
of the first valve and pushing it into its guide
which should have been fitted with a new oil
seal (photos).
18Fit the spring seat. Fit the valve spring so
that the closer coils are towards the cylinder
head and then fit the spring retaining cap.
19Compress the valve spring and locate the
split cotters in the valve stem cut-out (photo).
20Gently release the compressor, checking
to see that the collets are not displaced.
21Fit the remaining valves in the same way.
22Tap the end of each valve stem with a
plastic or copper-faced hammer to settle the
components.
23The cylinder head is now ready for
refitting as described in Section 7.
18 Examination and renovation
4
1With the engine stripped down and all parts
thoroughly clean, it is now time to examine
everything for wear. The following items
should be checked and where necessary
renewed or renovated as described in the
following Sections.
Cylinder block and crankcase
2Examine the casting carefully for cracks
especially around the bolt holes and between
cylinders.
3The cylinder bores must be checked for
taper, ovality, scoring and scratching. Start by
examining the top of the cylinder bores. If they
are at all worn, a ridge will be felt on the thrust
side. This ridge marks the limit of piston ring
travel. The owner will have a good indication
of bore wear prior to dismantling by the
quantity of oil consumed and the emission of
blue smoke from the exhaust especially when
the engine is cold.
4An internal micrometer or dial gauge can be
903 cc engine 1•17
17.19 Fitting split collets17.17B Inserting a valve into its guide17.17A Valve stem oil seal
1
Press a little grease into the
gap between the cylinder
walls and the two pistons
which are to be worked on.

clearance and end gap. Both clearances
should be checked with a feeler gauge. Check
the end gap when the ring has been pushed
squarely down the cylinder bore for two or
three inches (photos).
25If new rings are being used and the
cylinder bores have not been rebored, always
make sure that the top compression ring has
been stepped to prevent it contacting the
bore wear ridge.
Flywheel
26Check the clutch mating surface of the
flywheel. If it is deeply scored (due to failure to
renew a worn driven plate) then it may be
possible to have it surface ground provided
the thickness of the flywheel is not reduced
too much.
27If lots of tiny cracks are visible on the
surface of the flywheel then this will be due to
overheating caused by slipping the clutch or
“riding” the clutch pedal.
28With a pre-engaged type of starter motor
it is rare to find the teeth of the flywheel ring
gear damaged or worn but if they are, then the
ring gear will have to be renewed.
29To remove the ring gear, drill a hole
between the roots of two teeth taking care not
to damage the flywheel and then split the ring
with a sharp cold chisel.
30The new ring gear must be heated to
between 180 and 220ºC (356 and 428ºF)
which is very hot, so if you do not have
facilities for obtaining these temperatures,
leave the job to your dealer or engine
reconditioner.
31Where such facilities are available, then
the ring gear should be either pressed or
lightly tapped gently onto its register and left
to cool naturally, when the contraction of the
metal on cooling will ensure that it is a secure
and permanent fit. Great care must be taken
not to overheat the ring gear, as if this
happens its temper will be lost. A clutch input
shaft pilot bearing is not fitted on this engine.
Camshaft
32Examine the camshaft bearings for wear,
scoring or pitting. If evident then the bearings
will have to be renewed. The three bearingsare of different sizes and they can be removed
and new ones fitted using a bolt, nut and
distance pieces. When drawing a new bearing
into position, make sure that the oil hole is
correctly aligned with the one in the
crankcase. The centre and rear bearings
require reaming after fitting, the bearing at the
timing chain end is supplied ready reamed
(photo).
33The camshaft itself should show no marks
or scoring on the journal or cam lobe
surfaces. Where evident, renew the camshaft
or have it reprofiled by a specialist
reconditioner.
34Check the teeth of the camshaft sprocket
for wear. Renew the sprocket if necessary.
Cam followers
35Examine the bearing surface of the cam
followers which are in contact with the
camshaft. Any indentations or cracks must be
rectified by renewal. Clean sludge and dirt
from the cam followers and check their fit in
their bores. Side to side rock is unusual
except at very high mileage.
Timing chain
36Examine the teeth on both the crankshaft
sprocket and the camshaft sprocket for wear.
Each tooth forms an inverted “V” with the
sprocket periphery and if worn, the side of
each tooth under tension will be slightly
concave in shape when compared with the
other side of the tooth, ie; one side of the
inverted “V” will be concave when compared
with the other. If any sign of wear is present
the sprockets must be renewed.
37Examine the links of the chain for side
slackness and particularly check the
self-tensioning links for freedom of
movement. Renew the chain if any slackness
is noticeable when compared with a new
chain. It is a sensible precaution to renew the
chain at about 60 000 miles (96 000 km) and
at a lesser mileage if the engine is stripped
down for a major overhaul.
Cylinder head
38This is covered in Section 17.
Rockers and rocker shaft
39Thoroughly clean out the rocker shaft. As
it acts as the oil passages for the valve gear,
clean out the oil holes and make sure they are
quite clear. Check the shaft for straightness
by rolling it on a flat surface. If it is distorted,
renew it.
40The surface of the shaft should be free
from any wear ridges caused by the rocker
arms. If it is not, the shaft will have to be
renewed. Blocked shaft oil holes often
contribute to such wear.
41Check the rocker arms for wear of the
rocker bushes, for wear at the rocker arm face
which bears on the valve stem, and for wear
of the adjusting ball ended screws. Wear in
the rocker arm bush can be checked by
gripping the rocker arm tip and holding the
rocker arm in place on the shaft, noting if
there is any lateral rocker arm shake. If any
shake is present, and the arm is very loose on
the shaft, remedial action must be taken. It is
recommended that a worn rocker arm be
taken to your local FIAT agent or automobile
engineering works to have the old bush drawn
out and a new bush fitted (photo).
42Check the tip of the rocker arm where it
bears on the valve head, for cracking or
serious wear on the case hardening. If none is
present the rocker arm may be refitted. Check
the pushrods for straightness by rolling them
on a flat surface.
Oil pump
43Unscrew the four securing bolts which
connect the two halves of the pump body.
44Clean all the components in a bath of
paraffin and dry them.
45Inspect the gears for wear or damage and
then check for wear in the following way.
46Insert a feeler blade between the tooth
peak and the body. This should be between
0.05 and 0.14 mm (0.0019 and 0.0055 in).
47Now place a straight-edge across the
body flange and check for gear endfloat. This
should be between 0.020 and 0.105 mm
(0.0008 and 0.0041 in). Where the clearances
exceed the specified limits, renew the pump.
48Check that the oil pressure relief valve
spring is in good condition and not deformed.
903 cc engine 1•19
18.41 Rocker components18.32 Camshaft bearing18.24B Checking piston ring end gap
1

removed and the weight of the car is again on
its roadwheels.
4Fill the cooling system.
5Fill the engine with oil.
6Replenish lost transmission oil.
7Reconnect the battery.
8Adjust the clutch pedal as described in
Chapter 5.
24 Engine- initial start-up after
overhaul or major repair
4
1Make sure that the battery is fully charged
and that all lubricants, coolant and fuel are
replenished.
2If the fuel system has been dismantled it will
require several revolutions of the engine on
the starter motor to pump the petrol up to the
carburettor.
3Turn the carburettor throttle speed screwthrough one complete turn to increase the idle
speed in order to offset the initial stiffness of
new engine internal components.
4As soon as the engine fires and runs, keep
it going at a fast idle speed and bring it up to
normal working temperature.
5As the engine warms up there will be odd
smells and some smoke from parts getting
hot and burning off oil deposits. The signs to
look for are leaks of water or oil which will be
obvious.
6Check also the exhaust pipe and manifold
connections as these do not always “find”
their exact gas tight position until the warmth
and vibration have acted on them and it is
almost certain that they will need tightening
further. This should be done, of course, with
the engine stopped.
7When normal running temperature has
been reached, adjust the engine idle speed as
described in Chapter 3.
8Stop the engine and wait a few minutes tosee if any lubricant or coolant is dripping out
when the engine is stationary.
9Road test the car to check that the timing is
correct and that the engine is giving the
necessary smoothness and power. Do not
race the engine - if new bearings and/or
pistons have been fitted it should be treated
as a new engine and run in at a reduced
speed for the first 500 km (300 miles).
10After the first 1500 km (900 miles) the
cylinder head bolts must be re-torqued in the
following way (engine cold).
11Remove the air cleaner and rocker cover.
Unscrew the first bolt (Fig. 1.7) through a
quarter turn and then tighten it to final stage 2
torque (see Specifications).
12Repeat on the remaining bolts, one at a
time.
13Check and adjust the valve clearances
(Section 5).
14Refit the rocker cover and air cleaner.
903 cc engine 1•23
26.4 Shim engraved mark26.2 Removing a shim from a cam follower25.4 Checking a valve clearance
1
Part 3: 1116 cc and 1301 cc engines
25 Valve clearances- checking
2
This should only be required if the valves
have been renewed or ground in, or at high
mileages when noise or poor engine
performance indicates that a check is
necessary.
It is important that each valve clearance is
set correct otherwise the timing will be
wrong and engine performance poor. If there
is no clearance at all, the valve and its seat
will soon burn. Always set the clearances
with the engine cold.
1Remove the camshaft cover. Jack-up a
front wheel and engage top gear so that by
turning the wheel, the crankshaft can be
rotated.
2Each valve clearance must be checked
when the high point of the cam is pointing
directly upward away from the cam follower.
3Check the clearances in the firing order
1-3-4-2, No. 1 cylinder being at the timing
belt end of the engine. This will minimise the
amount of crankshaft rotation required.4Insert the appropriate feeler blade
between the heel of the cam and the cam
follower shim of the first valve. If necessary
alter the thickness of the feeler blade until it
is a stiff, sliding fit. Record the thickness,
which will, of course, represent the valve
clearance for this particular valve (photo).
5Turn the crankshaft, check the second
valve clearance and record it.
6Repeat the operations on all the remaining
valves, recording their respective clearances.
7Remember that the clearance for inlet and
exhaust valves differs - see Specifications.
Counting from the timing cover end of the
engine, the valve sequence is:
Inlet 2-3-6-7
Exhaust 1-4-5-8
26 Valve clearances-
adjustment
3
1Check the valve clearances (Section 25).
2Clearances which are incorrect will mean
the particular shim will have to be changed.
To remove the shim, turn the crankshaft untilthe high point of the cam is pointing directly
upward. The cam follower will now have to
be depressed so that the shim can be
extracted. Special tools (A60642 and
A87001) are available from your Fiat dealer to
do the job, otherwise you will have to make
up a forked lever to locate on the rim of the
cam follower. This must allow room for the
shim to be prised out by means of the
cut-outs provided in the cam follower rim
(photo).
3Once the shim is extracted, establish its
thickness and change it for a thicker or
thinner one to bring the previously recorded
clearance within specification. For example,
if the measured valve clearance was 1.27
mm (0.05 in) too great, a shim thicker by this
amount will be required. Conversely, if the
clearance was 1.27 mm (0.05 in) too small, a
shim thinner by this amount will be required.
4Shims have their thickness (mm) engraved
on them; although the engraved side should
be fitted so as not to be visible, wear still
occurs and often obliterates the number. In
this case, measuring their thickness with a
metric micrometer is the only method to
establish their thickness (photo).