Peugeot 205. Manual - part 21

3

Chapter 3
Cooling, heating and air conditioning systems

General

System type  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Pressurised with expansion tank/bottle and front-mounted radiator,
electric cooling fan, coolant pump and thermostat

Pressure cap setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0.8 or 1.0 bar (according to engine)

Thermostat

Start-to-open temperature:

XV, XW and XY series engines  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

79° to 82°C

XU series engines  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

82°C

TU9 series, TU3 series and TU1 series (Van) engines  . . . . . . . . . . . .

88°C

TU1 series (except Van) engines  . . . . . . . . . . . . . . . . . . . . . . . . . . . .

83°C

Fully-open temperature:

XU, XV, XW and XY series engines . . . . . . . . . . . . . . . . . . . . . . . . . . .

93°C

TU9 series, TU3 series and TU1 series (Van) engines  . . . . . . . . . . . .

102°C

TU1 series (except Van) engines  . . . . . . . . . . . . . . . . . . . . . . . . . . . .

96°C

Torque wrench settings

Nm

lbf ft

Coolant pump attachments:

XV, XW, and XY series engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13

10

XU series engines  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

15

11

TU series engines:

Housing inlet elbow (aluminium block engines)  . . . . . . . . . . . . . . .

8

6

Housing bolts (aluminium block engines):

Small bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

30

22

Large bolts  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

50

37

Coolant pump bolts (cast-iron block engines):  . . . . . . . . . . . . . . . .

15

11

Air conditioning system check  . . . . . . . . . . . . . . . . . . . .See Chapter 1
Air conditioning system - general information and precautions  . . . . 10
Antifreeze - general information  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Auxiliary drivebelt check and renewal  . . . . . . . . . . . . . . .See Chapter 1
Coolant level check  . . . . . . . . . . . . . . . . . . . . . . .See “Weekly checks”
Coolant pump - removal and refitting  . . . . . . . . . . . . . . . . . . . . . . . . 8
Cooling system - draining  . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Cooling system - filling  . . . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Cooling system - flushing  . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1

Cooling system electrical switches and sensors - removal 

and refitting  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Cooling system hoses - disconnection and renewal . . . . . . . . . . . . . 2
General information and precautions  . . . . . . . . . . . . . . . . . . . . . . . . 1
Heater assembly - removal, dismantling, reassembly and refitting . . 9
Radiator - removal and refitting  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Radiator cooling fan - removal and refitting  . . . . . . . . . . . . . . . . . . . 6
Thermostat - removal, testing and refitting  . . . . . . . . . . . . . . . . . . . . 4

3•1

Specifications

Contents

Easy, suitable for
novice with little
experience

Fairly easy, suitable
for beginner with
some experience

Fairly difficult,
suitable for competent
DIY mechanic

Difficult, suitable for
experienced  DIY
mechanic

Very difficult,
suitable for expert DIY
or  professional

Degrees of difficulty

5

4

3

2

1

1

General information and
precautions

The cooling system is of pressurised type

incorporating an expansion bottle or expansion
tank according to model. The system includes
a front-mounted cross-flow radiator,
thermoswitch controlled electric cooling fan,
coolant pump and thermostat. The car interior
heater matrix is incorporated into the coolant
circuit with the interior air supply and
distribution being controlled by air flaps.

On XU and TU Series engines the coolant

pump is driven by the engine timing belt, but
on all other engines it is driven by the auxiliary
(alternator) drivebelt.

The cooling system functions in the

following way. After a cold start the
thermostat valve is shut and coolant
circulation is restricted to the engine and
heater matrix. When the coolant reaches the
normal engine operating temperature the
thermostat starts to open and coolant
circulation also flows through the radiator. The
engine temperature is then controlled by the
thermostat and the electric cooling fan
located on the front of the radiator.

Air conditioning is available as an option on

certain models and is described in Section 10.

Precautions

Warning: Do not attempt to
remove the expansion tank filler
cap, or to disturb any part of the
cooling system, while it or the

engine is hot, as there is a very great risk of
scalding. If the expansion tank filler cap
must be removed before the engine and
radiator have fully cooled down (even
though this is not recommended) the
pressure in the cooling system must first
be released. Cover the cap with a thick
layer of cloth, to avoid scalding, and slowly
unscrew the filler cap until a hissing sound
can be heard. When the hissing has
stopped, showing that pressure is
released, slowly unscrew the filler cap
further until it can be removed; if more
hissing sounds are heard, wait until they
have stopped before unscrewing the cap
completely. At all times, keep well away
from the filler opening.

Warning: Do not allow antifreeze
to come in contact with your
skin, or with the painted
surfaces of the vehicle. Rinse off

spills immediately with plenty of water.
Never leave antifreeze lying around in an
open container, or in a puddle in the
driveway or on the garage floor. Children
and pets are attracted by its sweet smell,
but antifreeze is fatal if ingested.

Warning: Refer to Section 10 for
precautions to be observed
when working on vehicles
equipped with air conditioning.

2

Cooling system hoses -
disconnection and renewal

1

Note: Refer to the warnings given in Section 1
of this Chapter before proceeding. Hoses
should only be disconnected once the engine
has cooled sufficiently to avoid scalding.
1 If the checks described in Chapter 1 reveal
a faulty hose, it must be renewed as follows.
2 First drain the cooling system (Chapter 1); if
the antifreeze is not due for renewal, the
drained coolant may be re-used, if it is
collected in a clean container.

Models with conventional hose
connections

3 To disconnect any hose, use a pair of pliers
to release the spring clamps (or a screwdriver
to slacken screw-type clamps), then move
them along the hose clear of the union.
Carefully work the hose off its stubs. The hoses
can be removed with relative ease when new -
on an older vehicle, they may have stuck.
4 If a hose proves to be difficult to remove, try
to release it by rotating it on its unions before
attempting to work it off. Gently prise the end
of the hose with a blunt instrument (such as a
flat-bladed screwdriver), but do not apply too
much force, and take care not to damage the
pipe stubs or hoses. Note in particular that the
radiator hose unions are fragile; do not use
excessive force when attempting to remove
the hoses.

5 When refitting a hose, first slide the clamps
onto the hose, then engage the hose with its
unions. Work the hose into position, then
check that the hose is settled correctly and is
properly routed. Slide each clip along the
hose until it is behind the union flared end,
before tightening it securely.

Models with CONRAD “click-on”
radiator hose connections

6 Some TU3FM engine models may be fitted
with pre-production “click-on” radiator hose
connections. These fittings were only fitted to
a limited number of vehicles, and have now
been discontinued in favour of conventional
hose clips.

7 The hose end fitting is retained by a large
circlip, which must be extracted before pulling
the hose out (see illustration).
8 When refitting, first fit the circlip into the
radiator fitting, placing the flat part in position
first, and bringing the ends into position one
at a time.
9 Ensure that the O-ring is in good condition,
and securely located in the hose end fitting. It
should not be necessary to lubricate the
O-ring to fit it, but if any form of lubrication is
used, the radiator must be refilled with fresh
coolant, to avoid contamination.
10 Align the hose end fitting with the three
lugs in the radiator connection, push firmly
into place, and check that the hose is secure
by pulling back on it.

All models

11 Refill the system with coolant (see
Chapter 1).
12 Check carefully for leaks as soon as
possible after disturbing any part of the
cooling system.

3

Antifreeze - general
information

Note: Refer to the warnings given in Section 1
of this Chapter before proceeding.
1 The cooling system should be filled with a
water/ethylene glycol-based antifreeze
solution, of a strength which will prevent
freezing down to at least -25°C, or lower if the
local climate requires it. Antifreeze also
provides protection against corrosion, and
increases the coolant boiling point. As with all
engines of aluminium construction, the
corrosion protection properties of the
antifreeze are critical. Only a top quality
antifreeze should be used in the system and
should never be mixed with different
antifreeze types.
2 The cooling system should be maintained
according to the schedule described in
Chapter 1. If antifreeze is used that is not to
Peugeot’s specification, old or contaminated

3•2 Cooling, heating and air conditioning systems

2.7  CONRAD “click-on” type radiator hose

connection

1

Radiator fitting

2

Retaining clip

3

O-ring

4

Hose end fitting

If all else fails, cut the hose
with a sharp knife, then slit it
so that it can be peeled off in
two pieces. Although this

may prove expensive if the hose is
otherwise undamaged, it is preferable
to buying a new radiator.

If the hose is stiff, use a little
soapy water as a lubricant,
or soften the hose by
soaking it in hot water. Do

not use oil or grease, which may attack
the rubber.

coolant mixtures are likely to cause damage,
and encourage the formation of corrosion and
scale in the system.
3 Before adding antifreeze, check all hoses
and hose connections, because antifreeze
tends to leak through very small openings.
Engines don’t normally consume coolant, so if
the level goes down, find the cause and
correct it.
4 Ideally, a 50% mixture of antifreeze and
clean soft water (by volume) should be used
to maintain maximum protection against
freezing and corrosion. Mix the required
quantity in a clean container and then fill the
system as described in Chapter 1, and
“Weekly checks”. Save any surplus mixture for
topping-up.

4

Thermostat - removal, testing
and refitting

2

Note: Refer to the warnings given in Section 1
of this Chapter before proceeding.

Removal

1 The thermostat housing is located on the
cylinder head adjacent to the distributor.
2 Drain the cooling system as described in
Chapter 1.
3 Disconnect the radiator top hose from the
thermostat housing. Where necessary for
access, also remove the air inlet duct from the
air cleaner.
4 Unscrew and remove the two thermostat
housing cover bolts and remove the cover.

This may need a little persuasion with a
wooden or plastic-faced hammer (see
illustration).
5 Remove the thermostat. If it is stuck, do not
lever it out under its bridge piece, but cut
around its edge with a sharp knife.
6 Remove the rubber ring(s) and clean the
mating faces of the housing and cover.

Testing

7 If the thermostat is suspected of being
faulty, suspend it in a container of water which
is being heated. Using a thermometer, check
that the thermostat starts to open at the
specified temperature and is fully open also at
the specified temperature.
8 Remove the thermostat from the water and
allow it to cool. The valve plate should close
smoothly.
9 If the unit fails to operate as described or is
stuck open or shut, renew it with one of
similar temperature rating (see illustration).

Refitting

10 Refitting is a reversal of removal but use
new rubber sealing ring(s). Refill the cooling
system as described in Chapter 1 on
completion.

5

Radiator - removal and
refitting

2

Note: Refer to the warnings given in Section 1
of this Chapter before proceeding.

Removal

1 Drain the cooling system, as described in
Chapter 1.
2 Remove the front grille (see Chapter 11)
then unbolt the engine compartment front
crossmember (see illustration).
3 Disconnect the top and bottom hoses from
the radiator and, where applicable,
disconnect and unclip the vent hose for the
expansion tank (see illustration).
4 Disconnect the wiring from the cooling fan,
the thermo-switch and, where applicable, the
low level sensor. On TU series engines,
remove the cooling fan relay from the clip on
the top of the radiator (see illustrations).

Cooling, heating and air conditioning systems  3•3

3

4.9  Thermostat temperature rating

(arrowed) stamped on base

4.4  Removing the thermostat housing

cover on XV, XW and XY series engines

5.3  Expansion tank vent hose connection

on the radiator

5.2  Undo the bolts (arrowed) on each side

and lift off the front crossmember

5.4a  Disconnect the thermo-switch

(arrowed) . . .

5.4b  . . . and low coolant level sensor

wiring

5.4c  On TU series engines, remove the

cooling fan relay (arrowed)

If leakage is the reason for
wanting to remove the
radiator, bear in mind that
minor leaks can often be

cured using a radiator sealant with the
radiator in situ.

5 Disconnect the top mountings, as
applicable, then lift the radiator, complete with
cooling fan, from the car - taking care not to
damage the matrix (see illustration). The
base of the radiator incorporates pins which
locate in rubber mountings.
6 If necessary separate the cooling fan, with
reference to Section 6.

Refitting

7 Refitting is a reversal of removal; fill the
cooling system as described in Chapter 1 on
completion.

6

Radiator cooling fan -
removal and refitting

2

Removal

The radiator cooling fan may be removed

with the radiator, as described in the
preceding Section, and then separated.
Alternatively it may be unbolted or unclipped
(as applicable) from the radiator after having
removed the front grille and crossmember,
and disconnected the wiring. The motor can
be unbolted from the frame and then the fan
removed from the motor (see illustrations).
No spare parts are available for the motor. 

Refitting

Refitting is a reversal of removal.

7

Cooling system electrical
switches and sensors -
removal and refitting

2

Radiator cooling fan
thermoswitch

Removal

1 The thermostatically controlled switch for
the cooling fan is screwed into the radiator
side tank.
2 Drain the cooling system as described in
Chapter 1.
3 Disconnect the switch wiring and unscrew
the switch from its location. 

Refitting

4 Refitting is a reversal of removal, but use a
new sealing washer if necessary. Fill the
cooling system as described in Chapter 1 on
completion.

Coolant temperature sensor

Removal

5 The coolant temperature sensor may be
located in the left-hand end of the cylinder
head, on or beneath the thermostat housing,
or below the distributor, according to engine
type (see illustration). On some engines, two
sensors may be fitted, one for the temperature
gauge and another for the engine
management system. Testing should be
carried out by an auto-electrician or by
substitution with a known good unit.

6 Partially drain the cooling system (see
Chapter 1) to below the level of the sensor
unit.
7 Disconnect the wiring from the sensor and
unscrew it from its location. 

Refitting

8 Screw in the new unit, using a smear of
sealant on the threads or a new sealing
washer, as applicable. Reconnect the wiring.
9 Top-up the coolant level (see Chapter 1 and
“Weekly checks”).

Coolant level sensor

Removal

10 The coolant level sensor is located in the
radiator right-hand side tank on XV, XW and
XY series engines and in the expansion tank
on all other engines (see illustration). The
switch is float-operated and actuates a
warning lamp in the event of a low coolant
level.
11 The sensor is removed by unscrewing it
from its location after disconnecting the
wiring.

Refitting

12 Refitting is a reversal of removal using a
new sealing washer where necessary.

3•4 Cooling, heating and air conditioning systems

5.5  Disconnect the top mountings and lift

out the radiator

6.1a  Radiator cooling fan retaining clip

6.1b  Radiator cooling fan to frame

mounting bolts

7.5  Coolant temperature sensor location

on XV, XW and XY series engines

7.10  Cutaway diagram of the coolant level

sensor

1 Body
2 Terminal

connections

3 Float
4 Magnet
5 Reed contact

a Off position (float lifts magnet above reed

contact)

b On position (magnet field switches on reed

contact)