1983 FIAT UNO coolant capacity

2
System type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “No loss” with radiator and integral expansion tank. Electric cooling
fan, belt-driven coolant pump, thermostat on cylinder head
General
Radiator fan cuts in . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 to 94ºC (194 to 201ºF)
Radiator fan switches off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 to 89ºC (185 to 192ºF)
Thermostat opens:
903 cc engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 to 89ºC (185 to 192ºF)
1116 cc and 1301 cc engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 to 87ºC (181 to 188.6ºF)
Fully open:
903 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100ºC (212ºF)
1116 cc and 1301 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95ºC (203ºF)
Expansion tank pressure cap rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.78 bar (11 lbf/in2)
Coolant
Capacity:
903 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6 litre (8.1 pint)
1116 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0 litre (10.6 pint)
1301 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 litre (10.9 pint)
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ethylene glycol based antifreeze
Torque wrench settingsNm lbf ft
Temperature sender switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 36
Coolant pump mounting bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 25
Alternator adjuster and mountings nuts . . . . . . . . . . . . . . . . . . . . . . . . . 49 36
Chapter 2 Cooling and heating systems
For modifications, and information applicable to later models, see Supplement at end of manual
Coolant mixtures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Coolant pump - removal, overhaul and refitting . . . . . . . . . . . . . . . . 9
Cooling system - draining, flushing and refilling . . . . . . . . . . . . . . . . 2
Cooling system sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Description and maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Drivebelt - tensioning and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Fault finding - cooling and heating . . . . . . . . . . . . See end of ChapterHeater - dismantling, overhaul and reassembly . . . . . . . . . . . . . . . . 13
Heater unit - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Heating and ventilation system - description . . . . . . . . . . . . . . . . . . 11
Radiator - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Radiator fan thermostatic switch - removal, checking and refitting . 5
Radiator fan - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . 6
Thermostat - removal, testing and refitting . . . . . . . . . . . . . . . . . . . . 4
2•1
Specifications Contents
1 Description and
maintenance
1
1The cooling system consists of a
front-mounted radiator with built-in expansion
tank, a coolant pump (belt-driven from the
crankshaft pulley) and a thermostatically-
controlled electric cooling fan.
2In order to assist rapid warm-up, athermostat is located in a housing at the
left-hand end of the cylinder head. The hose
connections to the thermostat housing vary
according to model.
3The heater is supplied with coolant from the
engine and incorporates a matrix and blower
with the necessary controls.
4The throttle valve plate block of the
carburettor is coolant-heated as a means of
improving fuel atomisation.
5Maintenance is minimal as in theory no
coolant should ever be lost from theexpansion tank. Regularly check that the
coolant level is between 50.0 and 70.0 mm
(1.97 and 2.8 in) above the MIN mark on the
tank with the engine cold. The need for
regular topping up will indicate a leak
somewhere in the system. If one cannot be
found suspect an internal leak in the engine
although this is usually confirmed by a rise in
the engine oil level and water on the dipstick
(photo). Any topping-up should be done using
an antifreeze mixture (see Section 3), not plain
water.
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
54321

Cooling system (continued)
Radiator fan cut-in temperature:
1301 cc Turbo ie:
1st speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 to 90ºC
2nd speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 to 94ºC
1372 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 to 94ºC
Radiator fan switch-off temperature:
1301 cc Turbo ie:
1st speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 to 85ºC
2nd speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 to 89ºC
1372 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 to 89ºC
Coolant pump/alternator drivebelt tension:
1372 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Approximately 10 mm deflection midway between crankshaft and
alternator pulleys under firm thumb pressure
Torque wrench settingsNm lbf ft
Coolant pump mounting bolts (999/1108 cc) . . . . . . . . . . . . . . . . . . . . . 8 6
Coolant pump to crankcase (1372 cc) . . . . . . . . . . . . . . . . . . . . . . . . . . 25 18
Coolant temperature gauge sender unit (1372 cc ie) . . . . . . . . . . . . . . . 30 22
Coolant temperature sender unit (1372 cc) . . . . . . . . . . . . . . . . . . . . . . 27 20
Fan thermostatic switch (1372 cc) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 22
Thermal valve on inlet manifold (1372 cc):
M10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 15
M8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7
Water pump cover (1372 cc) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 11
Fuel system
General
Air cleaner element
999 cc and 1108 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion U520
1372 cc ie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion U533
1301/1372 cc Turbo ie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion U522
Fuel filter:
999 cc and 1108 cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion L101
1372 cc ie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion L201
1301/1372 cc Turbo ie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion L203
Carburettor calibration
Weber 32 ICEV 61/250 TLF 4/250
Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 903 cc 999 cc
Accelerator pump capacity (for 10 strokes) . . . . . . . . . . . . . . . . . . . . . . 3.8 to 6.3 cc -
Air bleed jet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.80 mm 50/90
Air compensating jet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - 165
Air idle jet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.60 mm -
Anti-flooding device (choke valve plate gap) . . . . . . . . . . . . . . . . . . . . . - 4.0 to 5.0 mm
Auxiliary venturi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5 mm -
Fast idle (throttle valve plate gap) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - 0.65 to 0.75 mm
Float level (with gasket) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.75 mm 26.75 to 27.25 mm
Full power jet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.50 mm 50
Emulsion tube . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F74 F70
Exhaust gas CO at idle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0 to 2.0% 1.0 to 2.0%
Idle air bleed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - 50/90
Idle jet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.47 mm 47
Idle mixture adjustment port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.50 mm -
Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750 to 800 rpm 750 to 800 rpm
Main jet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.10 mm 105
Needle valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.50 mm 1.5 mm
Pump jet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.40 mm 35
Pump outlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.40 mm -
Venturi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 mm 22 mm
Weber 32 TLF 4/252 (and 251) TLF 27/251
Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 999 cc 1108 cc
Accelerator pump capacity (for 10 strokes) . . . . . . . . . . . . . . . . . . . . . . 8 to 12 cc 8 to 12 cc
Air bleed jet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.65 mm 1.65 mm
Air idle jet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.50 mm 0.50 mm
Auxiliary venturi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 mm 4.5 mm
Emulsion tube . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F70 F70
13•10 Supplement: Revisions and information on later models

removal are in place under the
engine-to-gearbox bolts. Do not allow the
weight of the gearbox to hang on the input
shaft as it is engaged with the clutch friction
disc.
29Refit the starter motor, ensuring that the
wiring harness bracket is in position on the
top bolt.
30Locate the engine/transmission unit at the
front of the car and move it into position under
the engine compartment. Attach the lifting
sling and hoist as during removal.
31Enlist the aid of an assistant to help
steady the combined units as they are raised
into position and to locate the mountings in
the engine compartment.
32Once they are located, tighten the
mountings to the specified torque settings,
then disconnect the lifting hoist and sling.
33The remainder of the refitting and
reconnection procedures are a reversal of the
removal procedure described in Part C. For
further details on reconnecting the
suspension and driveshaft components,
refer to Chapter 7 and Section 13 of this
Chapter.
34Ensure that the exhaust downpipe-to-
manifold connection is clean and renew the
gasket when reconnecting this joint. Use a
smear of exhaust assembly paste on the jointfaces. Use new lockwashers and tighten the
flange nuts securely.
35Ensure that all fuel and coolant
connections are cleanly and securely made.
36Ensure that all wiring connections are
correct and securely made.
37Top up the engine and transmission oil
levels.
38Refill the cooling system.
39Check that all connections are securely
made, then reconnect the battery negative
lead.
Initial start-up after major
overhaul
40Refer to Chapter 1, Section 45.
8 Cooling system
PART A:
999 AND 1108 CC ENGINES
Description
1The operation and function of the cooling
system is essentially as described in Chapter
2 but note the location of the various
components and the routing of the coolant
hoses in Fig. 13.26.
Maintenance
2Topping-up, draining and refilling
procedures are as for 1116 and 1301 cc
engines in Chapter 2, but note that the
coolant capacity is different (see Specifica-
tions).
Thermostat -
removal and refittingÁ
3The thermostat is located on the left-hand
end of the cylinder head, below the
distributor.
4The thermostat cannot be renewed
independently of its housing and if faulty the
complete assembly must be renewed.
5Drain the cooling system.
6Although the thermostat housing can be
removed directly from the cylinder head,
better access is provided if the distributor is
first withdrawn as described in Section 10 of
this Chapter (photo).
7Disconnect the coolant hose from the
thermostat housing and unscrew the housing
flange bolts. Remove the assembly. Note that
it may be necessary to tap it free with a
plastic-faced or wooden mallet if stuck in
place.
8Remove the gasket and clean the mating
surfaces.
9Use a new gasket and bolt the assembly
into position (photo).
10Reconnect the coolant hose, then fill and
bleed the cooling system.
13•54 Supplement: Revisions and information on later models
Fig. 13.26 Cooling system circuit - 999 and 1108 cc engines (Sec 8A)
1 Coolant pump 2 Thermostat 3 Heater matrix
Fig. 13.27 Cooling system thermostat in open and closed positions - 999 and 1108 cc
engines (Sec 8A)8A.9 Fitting the thermostat housing. Note
the new gasket
8A.6 The thermostat housing (shown with
distributor removal) on the 999 cc engine