low oil pressure Citroen CX 1981 1.G Workshop Manual

Downloaded from www.Manualslib.com manuals search engine 1. HYDRAULIC FLUID :
\~ir/~rol 6jr/rol,/ir j111icl ( LHM ) is the only suitable type and must be used to the exclusion of all others in the
hydraulic system of the car.
This LHM fluid is gt~‘~,l
iv c-o/or/~ and similar to engine oil.
The use of nr!~’ oih~~- rc,otll$
twirl the rubber rinqs and seals in the system 2. RUBBER UNITS AND PARTS :
Suitable components are identified by their grcc’r/ colo/~r and may only be replaced by gc~rttri~ro wplor-c~t~~c~nf
col,,pollc,l/fs painted or marked in green.
All rubber components (joints, hoses, diaphragms, etc . . . ) are of a
spvcirfl qtrnlif), ior ~/.SCJ wifh idlfM (Iuid and are
identified by their white or green colour, 3. STORAGE :
ix Components must be stosed /11i1 o/ /Irlirl nr~tl blor~k~rl o!j: Like the piping they must be protected against shock
E and the inqress of dust
7 Rubber tubing and joints must be stored away from dust. air, light and heat.
al
co
0 LHM hydraulic fluid must be stored in its original containers carefully sealed We advise the use of litre ( for
: toppinq up ) or five litre containers ( for refillinq ) to avoid havinq to keep opened containers.
2
2 T-, 4. CHECKS BEFORE CARRYING OUT WORK :
Z +
c
E Before working on the hydraulic system in case of incorrect operation, ensure the following :
a
a a) T/FOI the c-r>ufrol.y or f/l<, rnc~ch~uir~~l livkrrgc~s o/ //I(’ uuits or f/lo gmltp o/ h\~d~c~u/i~ ~~~~it.s in(nln>d are HO/
lt?
sfi]/ it) o/~c,rnfiou.
b) and that the 111’ c-ire-/ii/ is ////(/(jr /~I.(Jss/II.(J. as follows :
With the engine at idling speed :
- Unscrew the pressure-release screw on the pressure requlator by one or one and one half turns : a sound
, of leakage should be heard from the requlator.
= Retighten the release screw : cut-out must occur which results in a reduction in the running noise
emitted by the H P pump.
If not check in the following sequence
- that there is sufficient fluid in the reservoir,
- that the reservoir filter is clean and in good condition,
= that the H.P pump is primed and there is no air leak on the suction side of the pump,
- that the release screw of the pressure requlator is correctly tightened

Downloaded from www.Manualslib.com manuals search engine 2
OPERATION No MA. 02 : I!‘orki//g OI/ hyc/rt/t/lic s\,s/vN/.
5. PRECAUTIONS TO BE TAKEN BEFORE WORKING ON THE HYDRAULIC SYSTEM :
a) (.~rvJuI/)~ CIVOII the area of work, the unions and the unit to be removed
Disconnect the lead from the negative terminal of the battery
Only use petrol or lead-free petrol for cleaning.
b ) I~~J/VNSO
the /)twsure in the circuits
- Place the vehicle in the G /arc B
position. stop the engine.
- Slacken the Pressure Requlator release screw.
Wait until the front of the car has reached the low position 6, PRECAUTIONS TO BE TAKEN DURING REMOVAL :
a) t3lnuk o!! the w~~tnl pi/~es with plugs, and rubber tubes with round pins of the correct diameter
b)
t3lmk of/ //IV op,c,/li,lg.s of components with pluqs of the correct diameter
NOTE : Plugs and pins must be carefully cleaned before insertion. 7.. CHECK OR TEST OF HYDRAULIC UNITS :
- Use 3654-T t~sf hc~~c-h equipped and designed for use with LHM fluid
This bench is /)ciitltc’d ~IY’~‘~/ and its accessories are marked in green.
- Never use the bench with another fluid or for testing components operating with another fluid (units of a (( D ))
car using LHS2 for instance ).
NOTE The (< Le Bozec )) pump used on test benches for checking DIESEL injectors can be resorted to for
testing components operating with LHM mineral fluid provided that the bench is cleaned first. 8. PRECAUTIONS TO BE TAKEN DURING REFITTING :
E steel pipes must be blown through with compressed air,
5 rubber tubes and joints must be washed in petrol or white spirit and then dried with compressed air,
= hydraulic units must also be cleaned with petrol or white spirit and blown through with compressed air.
NOTE Renew all joints and seals during refittinq .
b
) 12rlbrijicntim :
- Follow the indications as stated in the operations in the Manual..
- Joints and internal parts must be liqhtly oiled hefore fitting ( use mineral fluid LHM only )
L If parts in contact with hydraulic units have to be qreased use a mineral grease only ( as employed for
Cardan shafts or bearings ).

Downloaded from www.Manualslib.com manuals search engine OPERATION No MA. 02 : I+ 4’ 0, “‘g 01, Ill<, l1\~c!).ollli(- s\‘sfell~. Op. MA. 02
I To connect a union proceed as follows :
- Position sleeve-seal (( a u lightly coated with
L,HM fluid; this sleeve seal must not reach the
extremity of pipe (( b )).
- Centre the pipe in the housinq by lininq it up
with the axis of the hole, avoidinq all stress.
( Ensure that the end u b )I of the pipe enters
into the smali bore C< c )> j.
Start screwing in the union nut by hand.
- Tiqhten nut moderately : excessive force could
cause a leak because of deformation of the pipe
NOTE Tiqhteninq torques :
3.5 -mm pipe t 5.8 to 6 6 ft lbs
4 5 mm pipe 5 8 to 0 mN ( 0.8 to.0 9 ‘1 kg )
6 6 to 8 0 ft.lbs
6. O-mm pipe
1
9 to 11 mN (0 9 to 1 1 m.kg ) c ) Fittilzg :
I Only use joints of a quality compatible with LHM mineral fluid.
The design of the various seals ensures that their sealing action increases with fluid pressure The oiltiqhtness e
is therefore not improved by greater tiqhtness of the unions
2 To connect a rubber tube a rubber rinq of suitabie diameter has to be positioned between thr, tube and the hose
:
E clip.
0
x
a
A 9, CHECKS ON COMPLETION OF WORK
On completion of work on hydraulic units or the system itself check the followinq :
h) ‘1’11~ C./CJ~~~IIC-C, I~c,lrt,c,c,rt I/J<
pipvs : pipes must not touch one another or any other component, nor may any other
unit, whether fixed or movable, exert any stress on them.

Downloaded from www.Manualslib.com manuals search engine 5. Air-flow sensor ( DIAGRAM 5 )
- Disconnect the E.C.U.
- Using an ohmmeter check the continuity of circuits (( 6 )a, H 7 )) (( 8 H and (( 9 )) linking the air-flow sensor to
the multiple terminal board. as well as the continuity between each of the terminals
- The air-flow meter does not require any maintenance. It is not necessary to oil the flop. It must work without
high spot or catching
When the air-flow sensor is removed blank off the ducts so OS to protect it from dust
- Check the air circuit for air-tightness.
6. Resistors and injectors :
- A dirty injector may cause o lock of power. or on unstable idling speed.
- It is possible to test the functioning of the injectors with the engine idling by disconnecting each injector
in turn the engine rpm should decrease each time.
- Disconnect the E C U
- The resistance of an injector is 2 to 3 II.
- Each supplementary resistance is 5 to 7 R
- The volume delivered by an injector ( kept constantly open and under the normal operating pressure ) is
approximately 200 cm3 /min ( 12 25 cu in/min )-
- If the rubber pipe on one of the injectors appears wet on the outside, the injector must be replaced.
- Using an ohmmeter, check the continuity of the circuits

Downloaded from www.Manualslib.com manuals search engine 2 OPERATION No MA. 390-O : Checking the hydra&c conponmts on the.uehicle
f Mnnual sirrrin~ uehicles J CHECKS
4. Checking the main accumulator : a) Disconnect HP inlet pipe ( 1) from safety
valve.
b) Plug HP inlet pipe fusing p[u~s D
and E ). : c ) Tighten pressure regulator bleed screw.
Disconnect contact breaker lead from coil.
Operate storter,watching the pressure g”“ge :
the pressure should rise steadily and then
appear to stobilize.
Note this reading, which is the inflation
pressure of acc”mulator.
This preksure must equal 62 ‘, To
bars
(899 IE,psi) Corned lead of contact breaker
5. Checking cut-out :
a) Checking cut-out ~TPSSU~~~ : Start engine.
With pressure regulator bleed screw tightened,
examine the pressure gauge.
When pressure stops rising, reading indicates
maximum cut-out pressure.
This pressure m”st be equal to
170 t’5 bars
(2466 ?,73 p:i ). When the c”t-o”t pressure is obtained allow
the engine to nrn for a few minutes in order
to stabilize pressure.
Stop engine.
Examine the pressure gauge and note the fall
in pressure for the next 3
minutes. If the fall in’pressure exceeds
10 bark 4 145psi) check seai of plug D and repeat, the test sequence.
If the result of test is the some, the pressure
regulator is defective,
Replace it 01 repair it.
When cutout takes place, slightly slacken
pressure regulator bleed screw.
The pressure should fall gently then rise (IS~.
soon (IS the HP pump begins to operate.
The minimum reading indicated on tbe pressure
gauge corresponds to the cut-in pressure.
This pressure must be 145 +,5 bars
(2103 ?,73
psi ). If these cut-in and cot-out pressures do
not lie within the given tolerances, check the
pressure regulator.
c) Slacken the pressure regulator bleed screw.
d) Remove plug D and connect HP inlet pipe ( 1)
to safety valve.

Downloaded from www.Manualslib.com manuals search engine OPERATION No MA. 390-O : Checkin
P the hydraulic componm~s on the ucbicle Op. MA. 390-O 3
f Mama sleeting wbi&s I
6. Checking the safety valve :
=I
bl
Cl
dl
Remove safety v&e fixing screw ( 1 ).
Remove from safety valve :
supply pipe for front suspension (2 ),
- supply pipe for rem suspension (3):
Plug openings of safety valve ( pIugs E J.
Tighten pressure regulator bleed screw
and
start engine.
Disconnect rubher overflow return pipe and
watch aperture ~a>> of safety valve.
- I/ Iherr is a slight c7moa,,t 0, sHymge thr
sa/cty ~dve is s in good ordrv n.
el
-If thrr~ is a discharge of fluid the sniw
dw must be rqlacrd..
f ) Slacken pressure regulator bleed screw-
Conned overflow return pipe to safety valve.
Secure safety valve ( screw (( 1 a) 1.
7. Checking the safety valve slidevolve :
a) Remove plug from rem suspension outlet on
safety v&e at G b >a.
b ) Disconnect contact breaker lead on coil and
turn engine using stmter : fluid should start
to run through the opening a d N when pressure
reaches
1lLl +o 130 bars ( 1585 to 1885 psi )
c) Slacken pressure regulator bleed screw.
Connect contact breaker lead.
d ) Plug safety valve opening u b )) (plug E ).
8. Checking the hydraulic brake contml :
m ) Tighten pressure regulator bleed screw.
b) Start up engine.
When cut-out takes place wait a fen: seconds
for the pressure to stobilize.
Stop engine%
Watch pressure gauge and note the pressure
drop in the next 3
minutes. If pressure drop
exceeds 10 bors*( 145 psi ) repeat the test.
If the re< is the same. the broke control
valve is defective : change it.

Downloaded from www.Manualslib.com manuals search engine OPERATION No MA. 510-00 : \m//l‘!yc~tl/ <‘,/I 0 t Ih<’ <‘It,< Ir.itnl iusrtlllnliritt Op. MA. 510-00 3
f 0 lO7i-l,‘1975 )
DESCRIPTION OF THE COMPONENTS
!ep. Description and Position Rep. ‘D escription and Position
1
Right hand sidelamp ...... 74 51
Flasher unit .. ....... 21
Front right hand direction indicator ..... 21 52 Lighting and starter switch .... .4 8’44- 61
2 Right-hand headlamp Main beam .. 78 5.3
76 54 Petrol gauge rheostat ........ 25
Dipped beam
Right hand window winder control switch
3 Right~hand horn ............ 42
( O/)liWlNl J ................. 51
4 Left-hand horn ...
41 55 Heating control illumination f ~///io~n/) .. 68
5 Left-hand headlamp : Main beam ....... 77 56
Left hand window winder switch ( O/JI~OII~/~~~
Dipped beam ...... 75 57
Heated rear window switch Op/io~nl j ...... 14
6 Front left-hand direction indicator ... 16 58
Lightinq switch unit ............. ........... 72
Front left hand sidelamp ................. 69
Speedometer and tachometer lighting
8 Electric fan thermal switch .................. 59
rheostat ....... ...... .................... 28 10
Electric fan .......
58 59 Instrument panel : 11
Starter ...... ... .............. .......... 3
Thermal voltmeter and illumination .. 26-28 12
Alternator ............................ ........ 5 13 Petrol gauge and illumination ............ 25-69
Ignition coil ... ......... .............. 61 14
Speedometer and tachometer lighting 28
High tension sensor ....................... 64
Clock and clock illumination ....... 1667 15
Compressor for horn ............ ..... ...... 43
Heated rear window warning lamp ....... 15 16
Compressor relay ................... ..... 43
Headlamp dipped beam warning lamp ... 75 17
Battery ............. .... .. 1
Brake pad wear warning lamp .......... 27 18
Voltage regulator ......................... 6
Oil temperature warning lamp ............ 35
19
HT sensor for No. 1 cylinder ........... 64
Coolant temperature warning lamp ....... 29 20
Distributor ..................... ...........
61 Emergency stop warning lamps 32” 34
21
Windscreen washer pump ............. 36
Hydraulic pressure warning lamp ...... 31 22
Plug for diagnostic operations ............. .65
Warning lamp for hazard warning.. ...... 17 23
Engine oil pressure switch .............. .. 34
Sidelamp warning lamp ................... 70 24
Idle cut-off ....................... .60
Direction indicators warning lamp ........... 23 25
Engine oil temperature switch ........... 35
Headlamp main beam warning lamp ... 77 26
Enqine coolant temp. switch ... 30 60 Left-hand control panel : 27
Top dead centre sensor ........................ 64 Direction indicator and hazard warning 19 28
Reversing lamp switch ........................ 8
- Horns .................................... 41 30
Window winder control relay( Optior~nl ) .. ..4 9
Windscreen wiper motor ............... 38-39 31
Heating relay ............ ..................... 45
- Windscreen washer pump .......... . .......... 37 32
Electric fan relay ................................ 58 61
Rear right-hand lamp cluster 33
Front right-hand brake unit ................. 28
- Rear lamp ............................................... 73 34
Windscre,en wiper motor ........................ 38
- Stoplamp ............. .....
............ 53
35
Blower motor ............ .............................. 45
Direction indicator ................................... 19 36
Hydraulic pressure switch ...................... . 32
- Reversing lamp ..................................... 9 37
Stoplamp switch.. ......................................... 53 62
Boot lamp ................................................. 12 38
Fuse boxes ..... 8-44-45-49-69-72 63 Rear window heating element ................... 14 39
Front left-hand brake unit .......................... 26 64
Right-hand number plate lamp ................. 72 41
Front right-hand door switch ................... 11 65
Left-hand number plate lamp ................... 70 42
Right-hand window winder motor f Optiollal) 51 66
Boot lamp switch ........................................ 12 43 Glove box
lamp ...................................... 51 67 Rear left-hand .lamp cluster 44
Front left-hand door switch ........ .......... 10 - Rear lamp ................................................ 71 45
Left-hand window winder motor (Oplio~fll) 47 s Stoplamp ........................................... 52 46
Interior lamp ................................................. 10
- Direction indicator lamp ..................... 18 47
Cigar lighter and illumination ............... .13-67
- Reversing lamp .................................... 8 48
Accessory plug ..... ... .......................... .... 50
49
Ashtray illumination ,., ... ................ 66 DESCRIPTION OF THE WIRING HARNESS
lot marked :
Front harness co Compressor harness AR
Rear harness C Boot harness
M Engine harness PC
Boot lid harness LG
Window operation D Fault finding harness ( Diagnostic) TB
Instrument panel harness FV Flying lead

Downloaded from www.Manualslib.com manuals search engine TABLE OF BULBS
Use No. Base
Type Voltage Wattage French standard
reference

ain and dipped beams 2 P. 45 t 41 yellow 12 v 40145 w R. 136-15
(for France)
Quartz-Iodine long-
range headlamps
( Optional ) 2 x 511 -H2 12
v 55 w R. 136-17
Direction indicator
lamps
Stop lamps
Reversing lamps Pear-shaped
BA.15s 19
P 25/l 12 v 21 w R. 136-12
Front side lamps and
rear lamps
Number plate lamps
Interior lamp
Boot lighting BA.lSs/ 19
Festoon 12 v 5w R. 136-13 12
v 5w R. 136-14
Dashboard lighting 5
BA. 9 s T 8/2 12 v 2w R. 136-34
Glovebox lighting 1
Warning lamp
Lighting for cigar
lighter
Ashtray lighting 13
1
1 Wedge base 12 v 1.2 w KEY TO CIRCUIT ,DIAGRAM SYMBOLS
Wiring connector
Connection block
Fuse
Switch, manual
Switch, mechanica
Switch, pressure
Switch, thermal 1 Capacitor
Motor, electric
0 Lighting
$ Warning lamp
4 a Instrument dial
Resistor
I
Rheostat
Coil winding

Downloaded from www.Manualslib.com manuals search engine TABLE OF FUSES
Supply to
eater unit relay Fuse
Circuits protected
Rating Colour
16 Amps Mauve Heater unit
S toplamps
Accessory terminal
Glove box lightinq
Positive terminal
of battery u + )) 16 Amps Red
E Direction indicators
Ignition Windscreen wipers and washers
switch Horns
Heater relay windinq
Window-winder relay winding
Rheostat -speedometer lighting
Warning lamp panel ( Battery
meter ( Thermal voltmeter-- Brake pad wear warning
lamp - Fuel gauge - Oil pressure warning lamp -
Hydraulic fluid pressure warning lamp-Water temp.
warning lamp )
16 Amps Green Interior lamp
Boot lamp
Cigar-lighter
Clock
Hazard warning lamps
E Voltage regulator
Iqnition Reversing lamps
switch
Rear window heating element
Handbrake warning lamp
Window winder relay 16 Amps White R.H. Switch 0 R.H. window winder
L.H. Switch- L.H. window winder
Lighting
Switch 10 Amps Yellow Ashtray lighting
Cigar lighting
Heater controls lighting
Instrument panel lighting Clock
E Battery meter
Odometers
Sidelamp warning
L.H. sidelamps, front and rear 1 amp
Lighting
Switch 10 Amps Blue R.H. sidelamps, front and rear
Number-plate lamp CIRCUIT DIAGRAM
>
P.T.O.

Downloaded from www.Manualslib.com manuals search engine OPERATION N” MA. 510-00 a : Arrnr~g(,v~ ('I, I 0 / Ih CJ c~lvclric-cil irtslnllc7liori Op. MA. 510-00 a 3
(I.‘1975 -7 1975 J
-
den{
lark
i
6
8
9
0
1
2
3
4
5
6
7
8
9
!l
!2
!3
!4
!5
!6
!7
!8
$0
)l
12
33
34
35
36
37
38
39
41
42
43
44
45
46
47
- DESCRIPTION OF COMPONENTS
Description and Location
‘ront R.H. sidelamp ................................... 74
‘rant R.H. direction indicator .................. 21
1.H. headlamp main beam ................. ..... 78
dipped beam ... .................. 76
3.H. horn 42 .............................................
,.H. horn ....................... ............. ............. 41
,.H. headlamp main beam .......................
77
dipped beam .................... 75
‘rant L.H. sidelamp .........
........................
69
:ront L.H. direction indicator .................. 16
I.T. sensor ............................................ 64
qnition coil ..............................................
61
3lower
motor .........................................
58
;tarter ...................................................... 3
Alternator ..................................................... 5
Xstributor 61 ...................................................
7lectric fan thermal switch .........................
59
Zompressor for horns ................................. 43
Compressor relay ..... .................
.............. 42
3attery ........... ...............................................
1
Joltaqe regulator ....................... ............. 6
Nindscreen washer pump ............. ............... 40
jacket for fault-finding ( diagnosfic) ....... 65
3il pressure switch .... ....................... ... 34
:dle cut-off ........................................... 60
3il temperature switch
35 .............................
Coolant temperature switch ....................... 30
T.D.C. sensor ......................................... 63
Switch for reversing lamps .......................... 8
Relay for window winder ............................. 49
Relay for heater unit 45
................... ..............
Relay for electric fan 58 ..................................
Front R.H. brake unit 28 ...............................
Windscreen wiper motor .............................. 38
Blower motor ................................................ 45
Hydraulic fluid pressure switch ................... 32
Stoplamp switch ........................................... 53
Fuse box ..... .................... 8-44-45-49-69-72
Front L.H. brake unit ........................... ... 26
Front R.H. door lighting switch ... ............
11
R.H. window-winder motor .......................... 51
Glove-box lighting ....................................... 51
Accessory terminal ......................................
5c
Lighting for pneumatic oil gauge .............. 3:
Front L.H. door lighting switch
.................. I[ L.H .
window-winder motor ........................... .47 DESCRIPTION C
No identification
AR
M
LG
TB
co
Front harness
Rear harness
Ynqine harness
dindow-winder harness
Instrument panel harness
Compressor harness jent.
/ark
4”9 50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
iz
67
68
69
70 Description and Location Central interior lamp ............ 10
Cigar-liqhter and lighting
.............. 13-66
Ashtray liqhtinq ...................................
67
Handbrake warning lamp flasher unit
........ 15
Switch for R.H. window-winder
.............. 51
Switch for L.H. window-winder ................ 47
Flasher unit .............................................. 21
Anti-theft switch ......................... 4-8-44-61
Rheostat for fuel qauqe ............................ 25
Switch for interior lamp ... ....................
9
Switch for heated rear window ...................
14
Liqhting for heater controls ..................... 68
Contact for handbrake
............................... 115
R.H. control unit ( liqhtinq )
................... 72
Lighting rheostat for tacho. and speedo.
28
Lighting for intrument panel ................ 68-69
Tachometer
............................................ 64
Battery meter (thermal voltmeter )
.......... 26
Fuel gauge unit
..... ....... ....... ................ 25
Lighting for odometers
....... ......... .......... 28
Clock and lighting ................................ 24-67
Warning lamp for heated rear window
15 .......
Warning lamp for dipped beam 75
_, .................
Warninq lamp for brake pads ................... 27
Warninq lamp for oil temperature
............ 35
Warning lamp for water temperature
.......... 29
Red u STOP 1) warninq lamp
............... 31-33
Warninq lamp for hydraulic fluid presssure 31
Warninq lamp for hazard warning
17
...............
Warninq lamp for sidelamps .................... 70
Warning lamp for direction indicators ...... 23
Warninq lamp for main beam ................. 77
Warning lamp for handbrake
..................... 16
L.H. control unit
Direction indicators and hazard warning lamps .........................................................
19
Horns .......................................................... 41
Windscreen wiper motor ....... .................. 38
Windscreen washer pump .......................... 40
Rear R.H. lamp cluster
Sidelamp ...................................................
73
Stoplamp ....................... .............................. 53
Direction indicator ......................................
19
Reversing lamp ....................... .............
9
Boot lamp ................................................... I2
Heated rear window 14 .....................................
R.H. numberplate lamp ...............................
70
L.H. numberplate lamp ...........
.................... 72
Contact for boot lamp .............................
12
Rear L.H. lamp cluster - Sidelamp
........ 71
,- Stoplamp
.......... 52
- Dir. indicator .. 18
- Rev. lamp ......... 8
IG HARNESSES
Boot harness
Boot-lid harness
Diagnostic harness
Handbrake harness
Flying lead