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Chapter 3
Cooling, heating and ventilation systems
Contents
Air conditioning compressor (auxiliary) drivebelt -
Cooling system electrical switches and sensors - testing,
checking and renewal See Chapter 1
removal and refitting 6
Air conditioning system - general information and precautions . . . . 11
Cooling system hoses - disconnection and renewal 2
Air conditioning system components - removal and refitting 12
Electric cooling fan(s) - testing, removal and refitting 5
Air conditioning system refrigerant check See Chapter 1
General information and precautions 1
Antifreeze mixture See Chapter 1
Heating and ventilation system - general information 8
Coolant level check See Chapter 1
Heater/ventilation components - removal and refitting 9
Coolant pump - removal and refitting 7
Heater vents - removal and refitting 10
Cooling system - draining See Chapter 1
Radiator - removal, inspection and refitting 3
Cooling system - filling See Chapter 1
Thermostat - removal, testing and refitting 4
Cooling system - flushing See Chapter 1
Degrees of difficulty
Easy, suitable for
Fairly easy, suitable
Fairly difficult, suitable
Difficult, suitable for
Very difficult,
novice with little
for beginner with
for competent DIY
experienced DIY
suitable for expert DIY
experience
some experience
mechanic
mechanic
or professional
Specifications
General
Maximum system pressure 1.4 bars
Thermostat
Opening temperatures:
Starts to open 89C
Fully-open 101C
Electric cooling fan(s)
Cooling fan(s) cut in:
Single-speed cooling fan:
1998 cc 8-valve models 95C
All other models 97C
Twin-speed cooling fan(s):*
Slow speed 97C
Fast speed 101C
Cooling fan(s) cut out:
Single-speed cooling fan:
1998 cc 8-valve models 86C
All other models 92C
Twin-speed cooling fan(s):*
Slow speed -. 92C
Fast speed 96C
'Twin-speed cooling fans are fitted to all models with air conditioning, and to models supplied to countries with a hot climate.
Torque wrench settings Nm ibf ft
Coolant pump bolts:
1124 cc and 1360 cc models:
Lower bolt 7 5
Upper bolt 16 12
1580 cc and larger-engined models 15 11
Temperature switches/sensors:
Screwed into radiator 35 26
Screwed into cylinder head/coolant outlet housing 18 13

3*2 Cooling, heating and ventilation systems
until a hissing sound is heard. When the
flat-bladed screwdriver), but do not apply too
1 General information and
hissing has stopped, indicating that the
much force, and take care not to damage the
pressure has reduced, slowly unscrew the
precautions
pipe stubs or hoses. Note in particular that the
filler cap until it can be removed; if more
radiator inlet stub is fragile; do not use
hissing sounds are heard, wait until they
excessive force when attempting to remove
General information
have stopped before unscrewing the cap
the hose.
The cooling system is of pressurised type,
completely. At all times, keep well away
comprising a coolant pump driven by the
from the filler cap opening, and protect
If all else fails, cut the hose
timing belt, an aluminium crossflow radiator
your hands.
with a sharp knife, then slit H
with integral expansion tank, electric cooling
Warning: Do not allow antifreeze
so that it can be peeled off in
fan(s), a thermostat, heater matrix, and all
to come into contact with your
two pieces. Although this may
associated hoses and switches.
skin, or with the painted surfaces
prove expensive if the hose is
The system functions as follows. Cold
of the vehicle. Rinse off spills
otherwise undamaged, It is preferable
coolant in the bottom of the radiator passes
immediately, with plenty of water. Never
to buying a new radiator. Check first,
through the bottom hose to the coolant pump,
leave antifreeze lying around in an open
however, that a new hose is readily
where it is pumped around the cylinder block
container, or in a puddle in the driveway or
available.
and head passages, and through the oil
on the garage floor. Children and pets are
cooler(s) (where fitted). After cooling the
attracted by its sweet smell, but antifreeze
cylinder bores, combustion surfaces and
can be fatal if ingested.
7 When fitting a hose, first slide the clips onto
valve seats, the coolant reaches the
Warning: If the engine is hot, the
the hose, then work the hose into position. If
underside of the thermostat, which is initially
electric cooling fan may start
crimped-type clips were originally fitted, use
closed. The coolant passes through the
rotating even if the engine is not
standard worm-drive clips when refitting the
heater, and is returned via the cylinder block
running. Be careful to keep your
hose. If the hose is stiff, use a little soapy
to the coolant pump.
hands, hair, and any loose clothing well
water as a lubricant, or soften the hose by
When the engine is cold, the coolant
clear when working in the engine
soaking it in hot water. Do not use oil or
circulates only through the cylinder block,
compartment.
grease, which may attack the rubber.
cylinder head, and heater. When the coolant
Warning: Refer to Section 11 for
8 Work the hose into position, checking that it
reaches a predetermined temperature, the
precautions to be observed when
is correctly routed, then slide each clip back
thermostat opens, and the coolant passes
working on models equipped
along the hose until it passes over the flared
through the top hose to the radiator. As the
with air conditioning.
end of the relevant inlet/outlet, before
coolant circulates through the radiator, it is
tightening the clip securely.
cooled by the inrush of air when the car is in
9 Refill the cooling system with reference to
forward motion. The airflow is supplemented
2 Cooling system hoses -
Chapter 1.
by the action of the electric cooling fan(s)
disconnection and renewal
10 Check thoroughly for leaks as soon as
when necessary. Upon reaching the bottom of
possible after disturbing any part of the
the radiator, the coolant has now cooled, and
Note: Refer to the warnings given in Section 1
cooling system.
the cycle is repeated.
of this Chapter before proceeding. Hoses
Radiator bottom hose
When the engine is at normal operating
should only be disconnected once the engine
temperature, the coolant expands, and some
has cooled sufficiently to avoid scalding.
Removal
of it is displaced into the expansion tank.
1 If the checks described in Chapter 1 reveal
Coolant collects in the tank, and is returned to
a faulty hose, it must be renewed as follows.
11 Turn the locking ring ("2") anti-clockwise
the radiator when the system cools.
until it contacts the stop ("1") (see
2 First drain the cooling system (see Chap-
illustration).
On models with automatic transmission, a
ter 1). If the coolant is not due for renewal, it
12 Press the connector away from the hose,
proportion of the coolant is recirculated from
may be re-used, providing it is collected in a
to ensure that the two retaining lugs are free
the bottom of the radiator through the
clean container.
(see illustration).
transmission fluid cooler mounted on the
3 To disconnect a hose, proceed as follows,
transmission. On 16-valve models, the
13 Pull the hose, complete with the
according to the type of hose connection.
coolant is also passed through the engine oil
connector, from the radiator.
cooler.
Conventional hose connections -
general instructions
The electric cooling fan(s) mounted in front
of the radiator are controlled by a
4 On conventional connections, the clips
thermostatic switch. At a predetermined
used to secure the hoses in position may be
coolant temperature, the switch/sensor
either standard worm-drive clips or
actuates the fan.
disposable crimped types. The crimped type
of clip is not designed to be re-used and
Precautions
should be replaced with a worm drive type on
Warning: Do not attempt to
reassembly.
remove the expansion tank filler
5 To disconnect a hose, use a screwdriver to
cap, or to disturb any part of the
slacken or release the clips, then move them
cooling system, while the engine
along the hose, clear of the relevant
is hot, as there is a high risk of scalding. If
inlet/outlet. Carefully work the hose free (see
the expansion tank filler cap must be
illustration). The hoses can be removed with
removed before the engine and radiator
relative ease when new - on an older car, they
have fully cooled (even though this is not
may have stuck.
recommended), the pressure in the cooling
6 If a hose proves to be difficult to remove, try
system must first be relieved. Cover the
to release it by rotating its ends before
cap with a thick layer of cloth, to avoid
attempting to free it. Gently prise the end of
scalding, and slowly unscrew the filler cap
2.5 Disconnecting the radiator top hose
the hose with a blunt instrument (such as a

Cooling, heating and ventilation systems 3*3
2.16 On refitting, fit a new O-ring
(arrowed) to the hose union
2.11 To release the radiator bottom hose
2.12 Press the connector away from the
connection, turn the locking ring (2) until it
hose, to ensure that the two retaining
contacts the stop (1)
lugs (3) are free
14 Recover the O-ring from the connector,
Radiator bypass hose connection
and discard it; a new one must be used on
Removal
refitting.
23 The hose is secured by means of a
Refitting
bayonet-fit connector.
15 Wipe the connector and the stub on the
24 Turn the connector on the end of the hose
radiator thoroughly with a clean, lint-free
anti-clockwise as far as it will go (see
cloth.
illustration).
16 Fit a new O-ring to the male half of the
25 Rock the connector back and forth to
connector, ensuring that it is correctly seated
release it from the radiator outlet. Remove the
(see illustration).
O-ring, and discard it; a new must be used on
2.18 Offer the hose to the radiator, with
17 Turn the locking ring clockwise until it
refitting.
the cut-out (arrowed) at the bottom
clicks.
Refitting
18 Offer the hose to the stub on the radiator,
the guide rails on the connector with the lugs
26 Wipe the connector and the stub on the
with the locating cut-out in the male part of
on the radiator (see illustration).
radiator thoroughly with a clean, lint-free
the connector located at the bottom (see
29 Push the connector fully home to
cloth.
illustration).
compress the O-ring.
27 Fit a new O-ring to the male half of the
30 Turn the connector clockwise as far as the
19 Push the connector into the stub until
connector.
stop.
both the retaining lugs click into position.
28 Offer the connector to the outlet on the
31 Refill the cooling system with reference to
Make sure that the O-ring is not trapped.
radiator, and twist anti-clockwise to engage
Chapter 1.
20 Pull the connector rearwards (away from
32 Check thoroughly for leaks as soon as
the stub) to adjust the position of the retaining
possible after disturbing any part of the
lugs if necessary.
cooling system.
21 Refill the cooling system with reference to
Chapter 1.
Heater matrix hose connections
22 Check thoroughly for leaks as soon as
Removal
possible after disturbing any part of the
33 The two hoses are connected to the
cooling system.
matrix by means of a single connector.
34 Prise the metal retaining clip from the top
of the connector (see illustration).
2.24 To release the radiator bypass hose,
2.28 On refitting, engage the guide rails (1)
2.34 Remove the metal clip from the top of
turn the connector on the end of the hose
with the lugs on the radiator, then twist the
the heater matrix connector on the engine
anti-clockwise
hose end in a clockwise direction
compartment bulkhead . . .

3*4 Cooling, heating and ventilation systems
2.35 . . . then release the plastic retaining 2.36 . . . and pull the connector away from 3.3 Removing the cover panel from the
clip . . . the bulkhead - recover the O-rings (arrowed) radiator
35 Release the plastic retaining clip by
4 Disconnect the wiring plug from the cooling
11 If the radiator is to be sent for repair or
pushing it towards the left-hand hose
fan switch (where fitted) on the left-hand side
renewed, remove all hoses, and the cooling
connection (see illustration).
of the radiator (see illustration).
fan switch (where fitted).
36 Pull the connector assembly from the
5 Disconnect the radiator upper hose(s) (left-
12 Inspect the condition of the radiator
heater matrix. Recover the O-ring seals from
hand side), and the lower hoses (right-hand
mounting rubbers, and renew them if
the connector, and discard them; new ones
side), with reference to Section 2.
necessary.
should be used on refitting (see illustration).
6 Depress the two retaining clips, located at
Refitting
Refitting
the top ends of the radiator, then carefully lift
the radiator from the vehicle. Note the locating
13 Refitting is a reversal of removal, bearing
37 Refitting is a reversal of the removal
lugs at the bottom of the radiator, which
in mind the following points:
procedure, using new O-rings.
locate in the mounting rubbers in the lower
(a) Ensure that the lower lugs on the radiator
38 Refill the cooling system with reference to
body panel (see illustrations).
Chapter 1.
are correctly engaged with the mounting
39 Check thoroughly for leaks as soon as
Inspection
rubbers in the body panel.
possible after disturbing any part of the
(b) Reconnect the hoses with reference to
7 If the radiator has been removed due to
cooling system.
Section 2, using new O-rings where
suspected blockage, reverse-flush it as
applicable.
described in Chapter 1. Clean dirt and debris
(c) On completion, refill the cooling system
3 Radiator -
from the radiator fins, using an air line (in
as described in Chapter 1.
removal, inspection and refitting
which case, wear eye protection) or a soft
brush. Be careful, as the fins are sharp, and
4 Thermostat -
Note: New sealing rings must be used when
easily damaged.
reconnecting the radiator lower hoses - see
8 If necessary, a radiator specialist can
removal, testing and refitting
Section 2. If leakage is the reason for
perform a "flow test" on the radiator, to
removing the radiator, bear in mind that minor
establish whether an internal blockage exists.
Removal
leaks can often be cured using a radiator
9 A leaking radiator must be referred to a
sealant with the radiator in situ.
specialist for permanent repair. Do not
1 Disconnect the battery negative lead.
attempt to weld or solder a leaking radiator,
2 Drain the cooling system as described in
Removal
as damage to the plastic components may
Chapter 1.
1 Disconnect the battery negative lead.
result.
3 Where necessary, release any relevant
2 Drain the cooling system as described in
10 In an emergency, minor leaks from the
wiring and hoses from the retaining clips, and
Chapter 1.
radiator can be cured by using a suitable
position clear of the thermostat housing to
3 Undo the three retaining screws, and
radiator sealant, in accordance with its
improve access. On 1905 cc models, access
remove the plastic cover panel from above the
manufacturer's instructions, with the radiator
is also improved if the air cleaner duct is
radiator (see illustration).
in situ.
removed (see Chapter 4).
3.4 Disconnecting the cooling fan switch
3.6a Depress the retaining clips . . .
3.6b . . . and withdraw the radiator
wiring plug

Cooling, heating and ventilation systems 3*5
4.4a Thermostat housing cover retaining
4.4b Thermostat housing cover retaining
4.5 Removing the sealing ring from the
bolts (arrowed) - 1360 cc models
bolts (arrowed) -1905 cc models
thermostat flange
4 Unscrew the retaining bolts, and carefully
earth point on the body; if not, then the earth
withdraw the thermostat housing cover to
5 Electric cooling fan(s) -
connection is faulty, and must be re-made.
expose the thermostat. Take care not to strain
testing, removal and refitting
4 If the switch and the wiring are in good
the coolant hoses connected to the cover
condition, the fault must lie in the motor itself.
(see illustrations).
The motor can be checked by disconnecting it
5 Lift the thermostat from the housing, and
Testing
from the wiring loom, and connecting a
recover the sealing ring(s) (see illustration).
1 Current supply to the cooling fan(s) is via
12-volt supply directly to it.
the ignition switch (see Chapter 5) and a fuse
Testing
Removal
(see Chapter 12). The circuit is completed by
6 A rough test of the thermostat may be
the cooling fan thermostatic switch, which (on
5 Remove the radiator as described in
made by suspending it with a piece of string in
most models) is mounted in the left-hand side
Section 3.
a container full of water. Heat the water to
of the radiator. On models with air
6 Disconnect the wiring plug from the rear of
bring it to the boil - the thermostat must open
conditioning, the cooling fans are controlled
the motor (see illustration).
by the time the water boils. If not, renew it.
by the "Bitron" sensor - see Section 6.
7 On models with a plastic radiator shroud
7 If a thermometer is available, the precise
2 If a fan does not appear to work, run the
(both single- and twin-fan arrangements),
opening temperature of the thermostat may
engine until normal operating temperature is
unscrew the three motor retaining nuts,
be determined; compare with the figures
reached, then allow it to idle. The fan should
rotating the fan blades as necessary so that
given in the Specifications. The opening
cut in within a few minutes (before the
the bolts can be counterheld from the front as
temperature is also marked on the thermostat.
temperature gauge needle enters the red
the nuts are unscrewed. Withdraw the motor
8 A thermostat which fails to close as the
section, or before the coolant temperature
assembly, complete with the fan, from the
water cools must also be renewed.
warning light comes on). If not, switch off the
front of the vehicle (see illustration).
ignition and disconnect the wiring plug from
Refitting
8 On models with a single cooling fan where
the cooling fan switch. Bridge the two
the motor is secured to the body by a metal
9 Refitting is a reversal of removal, bearing in
contacts in the wiring plug using a length of
frame, undo the retaining bolts, then remove
mind the following points:
spare wire, and switch on the ignition. If the
the motor and mounting frame from the
(a) Examine the sealing ringfs) for signs of
fan now operates, the switch is probably
vehicle.
damage or deterioration, and if necessary,
faulty, and should be renewed.
9 If desired, the fan blades can be removed
renew.
3 If the fan still fails to operate, check that
from the motor shaft, after its retaining screw
(b) Ensure that the thermostat is fitted the
battery voltage is available at the feed wire to
or clip (as applicable) has been removed.
correct way round, with the spring(s)
the switch; if not, then there is a fault in the
10 If the motor is faulty, the complete unit
facing into the housing.
feed wire (possibly due to a fault in the fan
must be renewed, as no spares are available.
(cj On completion, refill the cooling system
motor, or a blown fuse). If there is no problem
as described in Chapter 1.
with the feed, check that there is continuity
Refitting
between the switch earth terminal and a good
11 Refitting is a reversal of removal. Refit the
radiator as described in Section 3.
6 Cooling system electrical
switches and sensors -
testing, removal and refitting
Electric cooling fan thermostatic
switch - models without air
conditioning

Testing
1 Testing of the switch is described in
5.6 Disconnecting the wiring plug from a
5.7 Withdrawing a cooling fan motor
Section 5, as part of the electric cooling fan
cooling fan
assembly - twin-fan arrangement
test procedure.

3*6 Cooling, heating and ventilation systems
10 On completion, start the engine and run it
16 If the gauge needle remains at the "cold"
until it reaches normal operating temperature.
end of the scale when the engine is hot,
Continue to run the engine, and check that the
disconnect the sender wiring plug, and earth
cooling fan cuts in and out correctly.
the relevant wire to the cylinder head. If the
Electric cooling fan thermostatic
needle then deflects when the ignition is
switch - models with air
switched on, the sender unit is proved faulty,
conditioning
and should be renewed. If the needle still
does not move, remove the instrument panel
11 The cooling fans are controlled by the
(Chapter 12) and check the continuity of the
"Bitron" sensor. This is located in the
wire between the sender unit and the gauge,
thermostat housing, which is bolted onto the
and the feed to the gauge unit. If continuity is
left-hand end of the cylinder head - see
shown, and the fault still exists, then the
paragraphs 20 to 22.
gauge is faulty, and the gauge unit should be
renewed.
6.2 Electric cooling fan thermostatic
Coolant temperature
17 If the gauge needle remains at the "hot"
switch - models without air conditioning
gauge/temperature warning light
sender

end of the scale when the engine is cold,
disconnect the sender wire. If the needle then
Testing
returns to the "cold" end of the scale when
Note: On models with air conditioning, the
the ignition is switched on, the sender unit is
sender provides a signal to the gauge only.
proved faulty, and should be renewed. If the
The coolant temperature warning light is
needle still does not move, check the
operated by the "Bitron" temperature sensor
remainder of the circuit as described
described later in this Section.
previously.
12 The coolant temperature gauge/warning
18 The same basic principles apply to testing
light sender is screwed into the thermostat
the warning light. The light should illuminate
housing, which is bolted onto the left-hand
when the relevant sender wire is earthed.
end of the cylinder head. The sender can be
Removal and refitting
identified by its blue wiring connector (see
illustration)
.
19 The procedure is similar to that described
13 The temperature gauge (where fitted) is
previously in this Section for the electric
cooling fan thermostatic switch. On some
6.12 Coolant temperature
fed with a stabilised voltage from the
models, access to the switch is very poor, and
gauge/temperature warning light sender
instrument panel feed (via the ignition switch
other components may need to be removed
(arrowed) -1360 cc models
and a fuse). The gauge earth is controlled by
the sender. The sender contains a thermistor -
before the sender unit can be reached.
Removal
an electronic component whose electrical
"Bitron" temperature sensor -
2 The switch is located in the left-hand side
resistance decreases at a predetermined rate
models with air conditioning
of the radiator (see illustration). The engine
as its temperature rises. When the coolant is
Testing
and radiator should be cold before removing
cold, the sender resistance is high, current
the switch.
flow through the gauge is reduced, and the
20 The sensor forms part of the air
3 Disconnect the battery negative lead.
gauge needle points towards the blue (cold)
conditioning "Bitron" control system (see
4 Partially drain the cooling system to just
end of the scale. As the coolant temperature
Section 11). Testing of the sensor should be
below the level of the switch (as described in
rises and the sender resistance falls, current
entrusted to a Citroen dealer.
Chapter 1). Alternatively, have ready a
flow increases, and the gauge needle moves
Removal and refitting
suitable bung to plug the switch aperture in
towards the upper end of the scale. If the
the radiator when the switch is removed. If
sender is faulty, it must be renewed.
21 The "Bitron" temperature sensor is
this method is used, take great care not to
14 On models with a temperature warning
screwed into the thermostat housing, which is
damage the radiator, and do not use anything
light, the light is fed with a voltage from the
bolted onto the left-hand end of the cylinder
which will allow foreign matter to enter the
instrument panel. The light earth is controlled
head. The sensor can be identified by its
radiator.
by the sender. The sender is effectively a
brown wiring connector.
5 Disconnect the wiring plug from the switch.
switch, which operates at a predetermined
22 The procedure is similar to that described
6 Carefully unscrew the switch from the
temperature to earth the light and complete
previously in this Section for the electric
radiator, and recover the sealing ring (where
the circuit. If the light is fitted in addition to a
cooling fan thermostatic switch. On some
applicable). If the system has not been
gauge, the senders for the gauge and light are
models, access to the switch is very poor, and
drained, plug the switch aperture to prevent
incorporated in a single unit, with two wires,
other components may need to be removed
further coolant loss.
one each for the light and gauge earths. On
before the sender unit can be reached.
models with air conditioning, the light is
Refitting
Coolant temperature sensor - fuel
operated via the "Bitron" sensor - see
injection models
7 If the switch was originally fitted using
paragraphs 20 to 22.
sealing compound, clean the switch threads
15 If the gauge develops a fault, first check
Testing
thoroughly, and coat them with fresh sealing
the other instruments; if they do not work at
23 The fuel injection system coolant
compound.
all, check the instrument panel electrical feed.
temperature sensor is screwed into the
8 If the switch was originally fitted using a
If the readings are erratic, there may be a fault
thermostat housing, which is bolted onto the
sealing ring, use a new sealing ring on
in the voltage stabiliser, which will necessitate
left-hand end of the cylinder head. The sensor
refitting.
renewal of the stabiliser (the stabiliser is
can be identified by its green wiring
9 Refitting is a reversal of removal. Tighten
integral with the instrument panel printed
connector.
the switch to the specified torque, and refill (or
circuit board - see Chapter 12). If the fault lies
24 The sensor is a thermistor (see para-
top-up) the cooling system as described in
in the temperature gauge alone, check it as
graph 13). The fuel injection/engine
Chapter 1.
follows.
management ECU supplies the sensor with a

Cooling, heating and ventilation systems 3*7
are contained in the air distribution housing,
which acts as a central distribution unit,
passing air to the various ducts and vents.
3 Cold air enters the system through the grille
at the rear of the engine compartment. If
required, the airflow is boosted by the blower,
and then flows through the various ducts,
according to the settings of the controls. Stale
air is expelled through ducts at the rear of the
vehicle. If warm air is required, the cold air is
passed over the heater matrix, which is
heated by the engine coolant.
4 On models fitted with air conditioning, a
recirculation switch enables the outside air
supply to be closed off, while the air inside the
vehicle is recirculated. This can be useful to
7.3a On 1580 cc and larger-engined
7.3b . . . and remove the coolant pump
prevent unpleasant odours entering from
models, unscrew the retaining bolts
outside the vehicle, but should only be used
(arrowed)...
briefly, as the recirculated air inside the
set voltage and then, by measuring the
pump and the cylinder block are clean and
vehicle will soon become stale.
current flowing in the sensor circuit, it
dry.
determines the engine's temperature. This
5 On 1124 cc and 1360 cc models, fit a new
information is then used, in conjunction with
O-ring to the rear of the pump. Refit the pump
9 Heater/ventilation components
other inputs, to control the injector opening
to the engine, and tighten its retaining bolts to
time (pulse width). On some models, the idle
the specified torque.
- removal and refitting
speed and/or ignition timing settings are also
6 On 1580 cc and larger-engined models,
temperature-dependent.
position a new gasket on the rear of the
Heater/ventilation control unit
25 If the sensor circuit should fail to provide
pump. Offer the pump to the engine, ensuring
adequate information, the ECU'S back-up facility
that the gasket remains correctly positioned.
Removal
will override the sensor signal. In this event, the
Install the pump retaining bolts, and tighten
1 Disconnect the battery negative lead.
ECU assumes a predetermined setting which
them to the specified torque.
2 Remove the centre console as described in
will allow the fuel injection/engine management
7 Refit the timing belt as described in Chap-
Chapter 11. On lower-specification models
system to run, albeit at reduced efficiency.
ter 2.
where no centre console is fitted, undo the
When this occurs, the warning light on the
8 Refill the cooling system as described in
retaining screws and remove the heater duct
instrument panel will come on, and the advice of
Chapter 1.
cover (where fitted) from the centre of the
a Citroen dealer should be sought. The sensor
facia assembly.
itself can only be tested using special Citroen
diagnostic equipment. Do not attempt to test the
3 Where a radio/cassette player is fitted,
8 Heating and ventilation system -
circuit using any other equipment, as there is a
remove it as described in Chapter 12, then
general information
high risk of damaging the ECU.
undo the two retaining screws and remove the
mounting bracket from the radio aperture (see
Removal and refitting
1 The heating/ventilation system consists of a
illustrations). Where no radio/cassette player
26 The procedure is similar to that described
four-speed blower motor (housed behind the
is fitted, carefully prise out the storage box
previously in this Section for the electric
facia), face level vents in the centre and at
from the centre of the facia panel.
cooling fan thermostatic switch. On some
each end of the facia, and air ducts to the
4 Undo the four centre vent panel retaining
models, access to the switch is very poor, and
front footwells.
screws (two located above the heater
certain components may need to be removed
2 The control unit is located in the facia, and
controls, and two directly below), then unclip
before the sensor can be reached.
the controls operate flap valves to deflect and
the panel and withdraw it from the facia.
mix the air flowing through the various parts of
Disconnect the wiring connectors from the
the heating/ventilation system. The flap valves
cigarette lighter and ashtray illumination bulb,
7 Coolant pump -
removal and refitting
Removal
1 Drain the cooling system as described in
Chapter 1.
2 Remove the timing belt as described in
Chapter 2.
3 Slacken and remove the retaining bolts,
and withdraw the pump from the cylinder
block (see illustrations). Recover the pump
O-ring (1124 cc and 1360 cc models) or
gasket (1580 cc and larger-engined models).
A new O-ring or gasket should be used on
refitting.
Refitting
9.3a Undo the two retaining screws
9.3b . . . and remove the mounting bracket
4 Ensure that the mating surfaces of the
(arrowed)...
from the radio aperture

3*8 Cooling, heating and ventilation systems
9.4a Undo the four centre vent panel
9.4b . . . and withdraw the panel from the
9.5 Undo the heater panel retaining
retaining screws (arrowed)...
facia
screws, and release the clip (arrowed)
and remove the centre vent panel assembly
6 Disconnect the control cables and the
Refitting
from the vehicle (see illustrations).
wiring connector(s) from the rear of the heater
5 Undo the two heater control panel retaining
10 Refitting is a reversal of removal.
control panel, noting their locations, and
screws, then release the lower panel retaining
withdraw the panel from the vehicle.
Heater matrix
clip and manoeuvre the panel out from the
Removal
centre of the facia (see illustration).
Refitting
11 Remove the facia assembly as described
7 Refitting is reversal of removal, bearing in
in Chapter 11.
mind the following points:
12 Remove the retaining screws, and release
(a) Ensure that the control cables are
the wiring retaining brackets from the top of
correctly reconnected to the control
the heater unit, noting their locations (see
panel, as noted before removal.
illustration).
(b) Refit the radio/cassette player with
13 Working inside the vehicle, disconnect the
reference to Chapter 12.
wiring plug from the right-hand side of the
Heater/ventilation control cables
heater unit (see illustration).
Removal
14 Remove the heater assembly lower
retaining bolt (see illustration).
8 Remove the complete heater assembly as
15 Working in the engine compartment,
described later in this Section.
remove the two heater unit retaining nuts from
9 The cables can now be disconnected from
the bulkhead (below the heater matrix hose
the heater assembly and the heater control
connector), and recover the washers (see
9.9 Control cable connection (1) and
panel (see illustration). Note the locations of
illustration).
retaining clip (2) at heater assembly
the cables before disconnecting them.
16 Drain the cooling system as described in
9.12 Heater unit wiring bracket retaining 9.13 Disconnect the wiring plug from the 9.14 Heater assembly lower retaining bolt
screws (arrowed) right-hand side of the heater (arrowed)
9.15 Heater unit retaining nut on engine 9.17a Remove the two retaining screws
9.17b . . . and withdraw the retaining plate
compartment bulkhead
(arrowed)...
from the bulkhead

Cooling, heating and ventilation systems 3*9
9.18 Withdrawing the heater unit
9.19 Withdrawing the heater matrix from
9.20a Undo the retaining bolts .
the heater assembly
Chapter 1. Disconnect the heater hose
lower facia panel (left-hand-drive models) or
27 Open the bonnet, and remove the six
connector from the heater matrix, with
the glovebox (right-hand-drive models), as
wiper motor cover/vent panel retaining
reference to Section 2.
applicable, with reference to Chapter 11.
screws. Carefully ease the cover out from
17 Remove the two retaining screws, and
22 Unscrew the three blower motor retaining
behind the windscreen sealing strip.
withdraw the retaining plate from the heater
screws, and lower the assembly from the facia
Disengage its front locating pegs, and
matrix hose connector (see illustrations).
(see illustration).
manoeuvre the panel away from the vehicle.
18 Working inside the vehicle, withdraw the
23 Pull off the cover and disconnect the two
28 Remove the plastic cover from the heater
heater unit, complete with the control panel
wiring plugs, then withdraw the assembly
blower motor intake duct.
(see illustration). Be careful not to spill
from the vehicle (see illustration).
29 Twist the resistor anti-clockwise to
coolant inside the car.
release it from the bracket, then disconnect
Refitting
19 Remove the retaining screws, where
the wiring plug and withdraw the unit (see
applicable, then release the clips and
24 Refitting is a reversal of removal.
illustrations). Tie a piece of string to the
withdraw the heater matrix from the heater
wiring connector, to prevent it falling back out
assembly (see illustration).
Heater blower motor resistor
of the duct.
Refitting
Removal
Refitting
20 Refitting is a reversal of the removal
25 Disconnect the battery negative lead.
procedure, bearing in mind the following
26 Remove the wiper arm as described in
30 Refitting is a reversal of removal, refitting
points:
Chapter 12.
the wiper arm with reference to Chapter 12.
(a) If a new matrix is to be fitted, unbolt the
hose connector elbow from the old
matrix, and fit it to the new matrix using
new O-rings (see illustrations).

(b) Reconnect the heater hoses to the matrix
with reference to Section 2.
(c) Refit the facia assembly as described in
Chapter 11.
(d) Refill the cooling system as described in
Chapter 1.
Heater blower motor
Removal
21 Working inside the vehicle, remove the
facia felt undercover and the driver's side
9.20b . . . and remove the hose connector
9.20c Fit the elbow to the new matrix,
elbow from the old heater matrix
using new O-rings
9.22 Unscrewing a heater blower motor
9.23 Pull off the cover (arrowed) and
9.29a To remove the heater blower motor
retaining screw
disconnect the wiring plugs
resistor...

3*10 Cooling, heating and ventilation systems
evaporator, where it changes from liquid
under high pressure to gas under low
pressure. This change is accompanied by a
drop in temperature, which cools the
evaporator. The refrigerant returns to the
compressor, and the cycle begins again.
3 Air blown through the evaporator passes to
the air distribution unit, where it is blown
through the heater matrix to achieve the
desired temperature in the passenger
compartment.
4 The heating side of the system works in the
same way as on models without air
conditioning (see Section 8).
9.29b . . . twist the unit anti-clockwise and
10.1 Withdrawing a facia side vent
5 The operation of the system is controlled
disconnect the wiring plug
electronically by the "Bitron" control unit,
Complete heater assembly
Facia centre vents
which controls the electric cooling fan(s), the
compressor, and the facia-mounted warning
Removal
Removal
light. Any problems with the system should be
31 Removal of the complete heater assembly
3 Remove the centre vent panel from the facia
referred to a Citroen dealer.
is described in paragraphs 11 to 18, as part of
as described in Section 9, paragraphs 1 to 4.
Precautions
the heater matrix removal and refitting
4 Working at the rear of the centre vent panel,
6 When an air conditioning system is fitted, it
procedure.
remove the retaining screws, then withdraw
is necessary to observe special precautions
Refitting
the vent assembly from the panel.
whenever dealing with any part of the system,
Refitting
32 Refitting is a reversal of removal, with
or its associated components. If for any
reference to paragraph 20.
5 Refitting is a reversal of removal.
reason the system must be disconnected,
entrust this task to your Citroen dealer or a
11 Air conditioning system -
refrigeration engineer.
10 Heater vents -
general information and
Warning: The refrigeration circuit
removal and refitting
precautions
contains a liquid refrigerant
(Freon), and it is therefore

Facia side vents
dangerous to disconnect any part
General information
of the system without specialised
Removal
1 An air conditioning system is available on
knowledge and equipment.
1 Carefully release the relevant vent from the
certain models (see illustration). It enables
7 The refrigerant is potentially dangerous,
facia, using a screwdriver (with a piece of card
the temperature of incoming air to be lowered,
and should only be handled by qualified
under the blade to avoid damage to the facia
and also dehumidifies the air, which makes for
persons. If it is splashed onto the skin, it can
trim), then withdraw the vent (see
rapid demisting and increased comfort.
cause frostbite. It is not itself poisonous, but
illustration).
2 The cooling side of the system works in the
in the presence of a naked flame (including a
same way as a domestic refrigerator.
cigarette) it forms a poisonous gas.
Refitting
Refrigerant gas is drawn into a belt-driven
Uncontrolled discharging of the refrigerant is
2 Simply push the nozzle into its housing in
compressor, and passes into a condenser
dangerous, and potentially damaging to the
the facia, ensuring that it is correctly engaged
mounted on the front of the radiator, where it
environment.
with the heater duct, until the retaining lugs
loses heat and becomes liquid. The liquid
8 Do not operate the air conditioning system
click into place.
passes through an expansion valve to an
if it is known to be short of refrigerant, as this
may damage the compressor.
12 Air conditioning system
components -
removal and refitting
Warning: Do not attempt to open
the refrigerant circuit. Refer to
the precautions given in

Section 11.
1 The only operation which can be carried out
easily without discharging the refrigerant is
renewal of the compressor drivebelt. This is
described in Chapter 1, Section 2 1 . (The
"Bitron" temperature sensor may be renewed
11.1 Schematic diagram of air
using the information in Section 6.) All other
conditioning system
operations must be referred to a Citroen
1 Compressor
5 Control valve
dealer or an air conditioning specialist.
2 Condenser
6 Evaporator
2 If necessary, the compressor can be
3 Drier bottle
7 Heater/ventilation
unbolted and moved aside, without
4 Pressostat
booster motor
disconnecting its flexible hoses, after
removing the drivebelt.