Land Rover 90 110 Workshop Rover Manual

							AIR CONDITIONING - L.H. & R.H. STEERING 1821 
Type of Evaporator 
Weather Air Temp F 
(C) 
. .* a-.~ I. >- 
						

							1821 AIR CONDITIONING - L.H. & R.H. STEERING 
FAULT 
A. HIGHHEAD PRESSURE 
B. LOWHEAD PRESSURE 
C. 
HIGH SUCTION 
PRESSURE 
5. LOW  SUCTION 
E. NOISY EXPANSION VALVE (steady  hissing) 
F.  INSUFFICTENT 
COOLING 
G. COMPRESSOR  BELT 
H. ENGINE NOISE ANDiOR VIBRATION 
CAUSE 
1. Overcharge of refrigerant. 
2.  Air in system. 
3. 
4.  Condenser  fan motor  defective. 
Condenser 
air passage  clogged  with dirt 
or other 
foreign  matter. 
I. 
2. 
3. Defective  compressor 
Undercharge 
of refrigerant;  evident by bubbles 
in  sight  glass  while  system  is operating. 
Split  compressor  gasket or leaking  valves 
1. Slack compressor  belt. 
2.  Refrigerant  flooding through evaporator  into 
suction line; evident  by ice  on suction  line and 
suction  service valve. 
Compressor  suction valve strainer  restricted. 
Leaking  compressor  valves, valve gaskets 
and/or service  valves. Rcceiveddrier stopped;  evident by temperature 
difference  between input and output  lines. 
3. Expansion  valve stuck open. 4. 5. 
6. 
1. Expansion  valve thcrmobulb  not operating. 
2. Expansion  valve sticking  closed 
3. Moisture  freezing in expansion vaivc orifice. 
Valve  outlet tube will frost while inlet hose  tube 
will  have littlc or no  frost. System operates 
Dust,  paper  scraps, or other debris  restricting 
evaporator  blower grille. 
Dcfcctivc  evaporator  blower motor, wiring,  or 
blower  switch. 1. 
5. 
I. Low refrigerant  charge; evident  by bubbles  in 
sight glass. 
I. !. 
I. Compressor  not pumping. 
Expansion 
valve not operating  properly. 
Low  refrigerant  charge; evident by bubbles  in 
sight  glass. 
!. Belt tension 
!. Excessive  head pressure. !. Incorrect  alignment of pulleys or worn  belt not 
riding  properly. 
1. Nicked or broken  pulley. i. Frozen compressor. 
. !. 
i. i. Rough idler pulley bearing. ;. 
1. _ 
I. Excessive  head pressure. 1. Incorrect  compressor ail. 
Loose or missing mounting  bolts. 
Broken  mounting  bracket, idler bracket, or brace. Loose llywheel or clutch  retaining  boit. 
Bent, 
loose, or improperly  mounted engine drive 
Incorrect  installation 
of clutch bearing seal. Insecure  mountings of accessories:  gcncrator, 
power  steering,  air filter,  etc. 
pulley. 
REMEDY 
1. Purge 
with bleed  hose until bubbles  start to appear in sight  glass;  then, add sufficient 
refrigerant  gas to clear sight glass. 
Slowly  blow charge  to atmosphere. 
Install  new drier;  evacuate  and charge  system. 
2. 
3. Clean 
condenser of debris. 
4.  Replace  motor. 
1. 
2. 
3. Replace compressor. 
Evacuate 
and recharge  the system. 
Check  for leakage. 
Replace  gasket and install  new drier,  evacuate, 
and  charge  the system. 
1. Adjust  belt tension. 2. Check  thermobulb.  Bulb should  be securely 
clamped  to clean  horizontal  section of copper 
suction  pipe. 
3. Replace  expansion  valve. 1. Replace compressor. 5. 
5. 
Replace  valves and/or gaskets.  Install new drier, 
evacuate,  and charge  the system. 
Install  new drier,  evacuate  and charge 
the system. 
I Warm  thcrmobulb  with hand Suction should 
rise  rapidly  to 20 Ibs. or more. If not, replace 
expansion-valve. 
Check  inlet side screen.  Clean if clogged.  Refer 
to  C-2 and  C-3. ?. 
3. Install  new drier, evacuate  and charge  the 
system. 
periodically. 
Refer  to Fault  Diagnosis 
for Elcctrical System. 
i. Clean  grilles  as required. 
j. 
. Leak test. Repair  or replace  components  as 
required. 
. !. 
i. 
Refer  to C-2, C-3,  D-2.  D-3 and E. Refer to B-1 and  E. 
Refer  to B
-2 and 8-3 
. With  tension  gauge adjust  to 100 Ibs. (45 kg); or tighten  until depression of about A inch (1,25 cm) occurs  across longest  span. 
Refer  to A-1 through  A-4 and C-6. !. 1. Repair  as needed. 
._ Replace  pulley. 8. Replace comprcssor. ~____~~ . Repair as necessary. .. Replace  defective  part. 
. Repair as necessary. . Replace  bearing. . Repair as necessary. 
#, Replace  bearing. . Repair as necessary 
. 
. Refer  to A-I, A-2, A-3, A-4 and C-6. Refer to Compressor Oil Level  Check. 
8  
						

							AIR CONDITION NG - L.H. & R.H. STEERING (821 
COMPRESSOR AND CLUTCH DIAGNOSIS 
COMPRESSOR CLUTCH WILL 
NOT  ENGAGE 
1 NO VOLTAGE  AT CLUTCH I 
. 
OPEN  FUSE 
PUSH-BUITTON SWITCH 
DEFECTIVE 
I FAULTY  WIRING 
POOR CLUTCH  GROUND 
v 
CYCLING  CLUTCH SWITCH 
J 
I 
IF CONTACT  OPEN 
REPLACE  SWITCH 
I 
I t I 
VOLTAGE  AT CLUTCH  LOW 
+ 
I OPEN CLUTCH-COIL~ 
7 
REPLACE  COIL 
COMPRESSOR  WILL NOT TURN  PROPERLY 
CLUTCH  ENGAGES  BUT SLIPS  OR SMOKES 
I I I 
t 
CLUTCH-SLIPPING 
c 
I I LOW  VOLTAGE  AT CLUTCH 
1 
CLUTCH COIL PARTIALLY 
SHORTED 
, c -4 
I SEIZEDCOMPRESSOR 1 I BELTS  SLIPPING I 
II 
r t id REPLACE  COMPRESSOR AND ADJUST BELT TO PROPER 
I CLUTCHASSEMBLY I I TENSION 
L It I 
I REPLACE  CLUTCH COIL 
9  
						

							1821 AIR CONDTTIONING - L.H. & R.H. STEERING 
MECHANICAL 
AIR  CONDITIONER 
BLOWER MOTOR  AND CONTROL  SYSTEM DIAGNOSIS 
t 
ENGTNE RUNNING  TO *I PROVIDE VACUUM 
I -1 MODE CONTROL LEVER  IN 
FLOOR DUMP  POSTTION 
LOWER 
MOTOR  OPERATIV 
i I 
f 
MODE CONTROL  LEVER 
IN DE-MIST POSITION  MODE CONTROL LEVER 
IN 
FASCIA  OUTLET  POSITION  AIR 
DISCHARGE  AT FASCIA 
I I I 1 
.c 
NO  AIR  FROM 
FASCIA  LOUVRES 
FAULTY  MODE DOOR 
VACUUM  SWITCH + FAULTY MODE DOOR NO DISCHARGE AIR FROM 
DE-MIST  OUTLETS 
c NO AIR DISCHARGE  FROM 
FLOOR  DUMPS 
I I FAULTY  BLOWER  WHEEL 
I 
c FAULTY MODE DOOR 
ACTUATOR  DOOR 
OPERATING  LINK 
DISCONNECTED  AT CONTROL 
LEVER  OR FLOOR  DUMP 
DOOR I I 
I BLOWER  MOTOR AND 
INSUFFICIENT HEATING 
HOT 
WATER  VALVE 
PASSENGERCOMPARTMENT AIR 1 CONTROL  OPERATIVE 11 I I I 
* 
TEMPERATURE  CONTROL  INSUFFICIENT COOLING 
INOPERATIVE  HOT WATER VALVE VACUUM 
SWTTCH  MIS
-ADJUSTED I I 
c 
I I 
I 1 
I 
HOT WATER VALVE VACUUM SWITCH MIS-ADJUSTED 
BLEND 
AIR DOOR 
BOWDEN CABLE 
DISCONNECTED  AT CONTROL 
LEVER  OR AT DOOR  CRANK  HOT 
WATER  VALVE STUCK IN CLOSED  POSITION 
VACUUM  LINE 
PINCHED 
I 
HOT  WATER VALVE  STUCK 
IN OPEN POSTTTON 
CLAMP  SLIPPING 
VACUUM LINE PINCHED 
OR  DISCONNECTED FROM 
ACTUATOR  OR SWITCH 
BLEND 
ATR 
DOOR 
MIS-ADJUSTED 
10  
						

							AIR CONDITIONING - L.H. & R.H. STEERING 1821 
e L. .z CHARGING  AND TESTING  EQUIPMENT 
Connecting  the gauge  set 
NOTE 
1: There  are two  methods  of connecting  the 
charging  and  testing  equipment,  depending on the 
operation  to be  carried  out.  The  method described  for 
‘evacuating 
or charging  with liquid  refrigerant’  also 
applies  to  ‘pressure test’ and ‘compressor  oil level 
check’  operations. 
.: :. 
NOTE 2: Various  types of charge and  test equipment 
are  available depending  upon the manufacturer  chosen 
by  the  user.  The equipment  illustrated may differ 
slightly  in  layout to that  possessed  by the user,  however, 
it  is  recommended  that the user  adheres  to  the 
appropriate  manufacturer’s  instructions for  the charge 
and 
test equipment  used in their workshop. 
% -NOTE:  The boxed  instructions  in the  following 
procedure  refer to compressors  with STEM  type 
valves. 
All other  instructions  refer  to SCHRADER 
type valves. 
Fitting 
1. Ensure  that all the  valves on the charging  and 
testing  equipment  are closed. Control  valves 
on the 
particular  equipment  selected are numbered 
1 to 4 
as illustrated. The sequence  may  vary on other 
proprietary  equipment. 
2. Mount a 11,3 kg (25 Ib) drum  of refrigerant  upside 
down  on  the support  at 
the rear of the  charging 
equipment, and  secure with the strap. 
ST 1393M 
6. Place  the vehicle in a ventilated  area away from 
open  flames  and heat  sources.  Stop the  engine, 
open  and secure  the bonnet. 
7. Check  that both  service  valves are fully  opcn 
(turned  anti
-clockwise). 
8. Put on the  safety goggles. 
9. Remove  the caps  from  the gauge  connections  on 
the  service  ports. 
10. Coat the threads  and flares  with refrigerant oil. 
11. Connect the  low pressure  charging line (blue) from 
valve No. 1 to the  comprcssor  suction service port. 
12. Connect the high  pressure  charging linc (rcd) from 
valve No. 2 to the  compressor  discharge scrvicc 
port. 
13. Using the service  wrench,  turn  the  suction 
service  valve stem ‘clockwise’  counting  the 
number 
of turns  necessary to close the valve. 
1 
ST 1392M ST 1412 M ‘ 
3. Connect the  hose  from the bottom of the charging 
cylinder  to the refrigerant drum  valve. 
4. Connect  the hose between  the bottom of the 
‘2 c charging  cylinder and the refrigerant  control valve 
5. Connect  the hose  between the  vacuum pump valve 
14. After the valve  is fully  closed,  turn the  stem 
out  (anti
-clockwise)  half the  number of turns 
counted,  this should  position 
the valve seat in 
i the mid  (test) position. 
11 
(No. 4). 
and the vacuum  control valve (No. 3).  
						

							182 I AIR CONDITIONING - L.H. & R.H. STEERING 
WARNING: Open connections  slowly, keeping  the 
15. Turn the stem on the  discharge  valve clockwise 
until the pressure  rises on the  discharge 
pressure  gauge. If the  system  is 
to be 
evacuated,  the discharge  service valve seat 
16. The charging  and testing  equipment  is now 
connected  and ready  for proceeding  with the 
required  operation. 
16. Close the compressor  discharge service port 
(turn  anti
-clockwise). --. 
Removing 
17. If the engine  has been  operated, it must be stopped 
prior  to disconnecting  the charging  and 
testing 
eq 
U i pm en t . 
18. Close  both service  ports (turn fully anti-clockwise) 
until fully closed. 
19. Close  all valves  on the charging  and testing 
equipment. 
20. Disconnect  the charging  lines from the service 
ports. 
21. Refit  the blanking  caps to the compressor  valve 
stems  and service  ports, and to the  charging  lines. 
22. Close the bonnet. 
AIR CONDITIONING SYSTEM 
OPERATIONS 
Depressurising 
NOTE:  The  air  conditioning  refrigeration  system 
contains 
‘Refrigerant 12’ under  pressure,  and before 
any  component 
is disconnected  or removed,  the system 
must be discharged  of all  pressure. 
Refrigerant 12 evaporates so rapidly  at normal 
atmospheric  pressures and temperatures that it  tends to 
freeze  anything  it contacts.  Extreme care must be taken 
to  prevent  any  liquid refrigerant  from  contacting  the 
skin  and especially  the eyes.  Should  any liquid 
refrigerant  get into  the eyes,  use  a few  drops  of sterile 
mineral oil  to wash  them  out and  then  wash  the eyes 
with a weak  solution  of boric  acid. Seek medical 
attention 
immediatcly even  though  the initial  irritation 
has ceased 
aftcr first  aid  treatment.  Always wear safety 
goggles 
whea epeaing refrigerant cnnnections. 
1. Place  the vehicle in a ventilated  area away  from 
2. Stop the engine. 
3. Open  and secure  the bonnet. 
4. Remove  the caps  from thc compressor  service 
5. Check that both  compressor  service valves are fully 
6. Close  all valves  on the charging  and testing 
7. Put on safety  goggles. 
8. Connect  the high  pressure  charging  line (red)  from 
valve 
No. 2 to  the  compressor  discharge service 
port. 
9. Run  the (blue)  hose to an open  tapped  container  of 
approximately  one litre  capacity.  Attach the hose 
to  the  container 
so that  it will  not blow  out of the 
container. 
The purpose of the  container  is to 
collect  any 
oil carried  by the  refrigerant. 
open 
flames  and heat  sources. 
ports. 
opened  (turned anti
-clockwise). 
equipment. 
*p-3. 
6,,,- 10. Open  the compressor  discharge service port a 
quarter 
of a  turn. 
11. Open  valve No. 2 fully. 
12. Slowly  open the valve No. 1 one turn to allow  the 
refrigerant  to escape, 
if necessary,  adjust the 
refrigerant  flow 
so that the oil captured in thc 
container  is not  blown out of the container. 
12 11 
ST 1413M 
13. Measure  the amount of oil discharged  from the 
system 
so that  an equal  amount  of new  oil can bc 
returned  to the  system  during the charging 
operation.  Discard the old 
oil. 
14. When  the gauge  pressure  is below 50 psi,  slowly 
open  the valve  No. 
1 to maintain  refrigerant  flow. 
15. When the pressure  has been  reduced,  and the 
system has been  completely  discharged,  close the 
valves 
Nos. 1 and 2 on the  charging  and testing 
equipment.  
						

							AIR CONDITIONING - L.H. & R.H. STEERING 
- 2. Adjust both service  valve seats to the mid 
(Test)  position. 
*F>, I .; 4. NOTE: If it is necessary to disconnect  the compressor 
hoses,  the compressor  should  be sealed  by fully  closing 
the  relevant  service  valve  (turn  fully  clockwise). 
It is 
essential to ensure  that  both  service  valves  are open 
before  operating  the  compressor.  Similarly  any other 
component  of the  refrigeration system should  be capped 
immediately when disconnected. 
18. Open  the refrigeration  drum valve. 
19.  Open 
the valve  at the  base of the charging  cylinder 
and  allow  approximately 
0,25 kg (0.5 Ib) of 
refrigerant  to enter 
the cylinder. 
20.  Close  the refrigeration  drum valve and the valve  at 
the  base 
of the charging  cylinder. 
21.  Open  the refrigerant  control valve (valve 
No. 4) 
and flush out the high  and low pressure  lines by 
opening  valves 
Nos. 1 and 2 momentarily  until a 
white  stream  of refrigerant  is observed. - 
ST 1414M 
22. Close all valves on the charging  and testing 
23.  The  air conditioning  system 
is now depressurised. 
equipment, 
and 
fit the blanking  caps. 
Evacuating 
Whenever the system has becii ~peiieb io iiie 
atmosphere it is necessary  that the system  be evacuated 
to  remove  all 
air and moisture. It is also an essential 
preliminary  operation 
to charging the system  with 
Refrigerant  12. The  evacuate  operation  also provides  a 
check  for leaks  due 
10 faulty  connections. 
::: 2. 
1. Depressurise  the air conditioning  system as 
previously  described,  then 
conncct the gauge set as 
detailed  under Charging  and Testing  Equipment. 
3. Open the low  and  high  pressure  valves Nos. 1 and 
2. 
4. Start  the vacuum  pump and check that thc vacuum 
pump  valve is open. 
5.  Slowly  open the vacuum  control valve 
No. 3. If the 
vacuum  is applied  to 
the system too quickly,  the 
residual  oil may  bc drawn  out. 
4 ST 1394M 
6. In evacuating  the system it is necessary to lower the 
pressure so that  the boiling  point of water in the 
system  is lower  than 
the surrounding  air 
tempcrature. At an ambient temperature of 23.SC 
(75F), it is necessary to lower the system  pressure 
to 29.5 in Hg vacuum to bring  the boiling  point of 
water to 22°C (72°F).  Atmospheric prcssure (and 
vacuum  gauge readings)  decrease 
as altitude 
increases  by 
approximalcly 25 mm (I in) IIg per 
300 
m (1000 ft).  The  following  chart provides a 
guide to the various  gauge readings at diflering 
altitudes, for the same 10 mm (0.4 in) Hg absolute 
pressure. 
Altitude, 
ft m Vacuum Reading in Hg mm 
0  0 29.5 
750 
1,000  300 
28.5  725 
2,000  600  27.4 
695 
3,000 
900 26.4  670 
4,000  1200  25.4 
645 
5 ,GUU i 5Oii 24.5 622 
6,000 1800 
23.5  596 
7,000  2100  22.6  574 
8,000  2400 
21 .a 554 
9,000  2700 
20.9 
530 
10,000 3000 20.1 510 
13  
						

							- 
82 
7. The low  side  gauge  should  indicate  a vacuum  of 
660 
mm (26  in) Hg  within  five minutes. 
8. Whilst  the system is evacuating, fill the  charging 
cylinder  by opening  the refrigerant  drum 
valvc. 
9. Open the valve  at the  base  of the  charging  cylinder 
and 
fill the  cylinder  with 1,0 kg (2.2 Ib) of 
refrigerant.  Liquid refrigerant will be observed 
rising  in 
the sight glass. 
10. As the refrigcrant stops  filling  the cylinder,  opcn 
the  valve 
at the top of the cylinder  (behind the 
control panel) intermittently,  to relieve  the head 
pressure  and allow  the refrigerant  to continue 
filling  the cylinder. 
11. When  the refrigerant  reaches the desired  level in 
the sight glass,  close both the valve  at the basc of 
the  cylinder  and 
the valve at the bottom of the 
refrigerant  tank. 
12. Ensure the top  cylinder  valve is fully  closed.  If 
bubbling  is present 
in the  sight  glass,  reopen the 
cylinder  base valve  momentarily  to equalise  the 
drum  and cylinder  pressures. 
13. If 660 mm (26 in)  Hg  of vacuum  is not  achieved 
within 
fivc minutes,  it signifies  either the system 
has  a leak 
or thc vacuum  pump is dcfcctive. 
Initially  check 
thc vacuum pump, if thc pump 
proves  to be  functioning  properly then investigate 
for  a leak 
in thc air  conditioning  system. 
14. Close thc vacuum control valve No. 3. 
15. Stop the vacuum  pump and allow  the vacuum  to 
hold  for fifteen  minutes,  then check  that there  is no 
pressure  rise (a 
loss of vacuum)  evident on the 
compound  gauge. Any pressure  rise denotes  a leak 
which  must be rectified  before 
procccding further. 
Refer 
to the  heading  titled ‘Leak  Detection’  later 
in this section. 
16. With thc system  satisfactorily  evacuated, the 
system  is ready 
for charging  with refrigerant. 
AIR CONDITIONING - L.H. & R.H. STEERING 
ST 1395M I” 
k 
Sweeping 
NOTE: This  operation  is in  addition  to evacuating,  and 
is  to  remove  moisture  from systems  that have  been open 
to  atmosphere  for 
a long period, or that are known  to 
contain  excessive  moisture. 
1. Fit a new liquid receiver/dricr, as detailed undcr 
the heading “Receiver/Drier”. 
2. Ensure  that  a full drum  of refrigerant  is fitted on 
the  charging  and testing  equipment. 
3. Fit the charging  and testing  equipment  as 
previously  described for evacuating  and evacuate 
the  air conditioning  system, allowing 
0,25 to 
0,45 kg (’h to 1 Ib) of refrigerant  to enter  the 
charging  cylinder. 
4. Close all valves  on the  charging  and testing 
equipment. 
5. Disconnect  the intake  hose from thc vacuum 
Pump. 
A 
ST 1396M 
n: % y* 
6. Connect thc intake  hose to thc valve  at the  top  of 
the charging  cylinder. 
7. Open the valve  at the  top  of the  charging  cylinder. 
8. Put on safety goggles, 
9. Crack  open the hose  connection  at valve No. 3 and 
allow  some refrigerant  to purge 
the hose,  then 
close  the connection. 
10. Open  the high  pressure  valve (No. 2). 
11. Slowly open valve No. 3, which is now connected 
to  the  top  valve  of the  charging  cylinder,  and allow 
gas  to flow  into the system  until the reading  on the 
compound  gauge remains  steady. Between 
0,25 
and 0,45 kg (I/? to 1 Ib) of refrigerant  will entcr the 
system. 
12. Allow the dry  refrigerant  introduced into the 
system 
to remain  for 10 minutes. 
14  
						

							AIR CONDITIONING - L.H. & R.H. STEERING IS21 
i( 13. Crack the suction valve charging  line at the service 
port  on  the  compressor  to allow  an escape 
of 
refrigerant,  at  the same  time observing thc sight 
glass 
in the  charging cylinder. A slight  drop in the 
level  should  be allwwed before  closing  the 
connection  at the  compressor. 
1. 
14. Close  the high pressure  valve (No. 2). 
15. Close valve No. 3. 
16. Close  the valve  at the  top  of the charging  cylinder. 
14-10 
ST 1397M 
17. Reconncct thc charging  and  testing equipment,  as 
described 
for evacuating  and evacuate  the  air 
conditioning system. 
18. Maintain  the  vacuum for twenty minutes.  The air 
conditioning  system is now  ready 
for charging  with 
refrigerant. 
Charging 
CAUTION: 
Do not  charge  liquid refrigerant  into the 
compressor.  Liquid cannot be  compressed;  and if liquid 
refrigerant  enters the compressor  inlet valve,  severe 
damage 
is possible;  in addition,  the oil charge may be 
absorbed  into the refrigerant,  causing damage  when the 
compressor 
is operated. 
1. Fit the  charging  and testing  equipment as 
previously  described for evacuating. 
2. Evacuate the air conditioning  system  allowing 
1,0 kg (2.2  Ib) of refrigerant  to enter the  charging 
rvlinrier -J  3. Put on safety goggles. 
4. Close  the low pressure  valve (No. 1). 
5. Open the refrigerant  control  valve (No. 4) and 
release  liquid refrigerant  into the system  through 
the  compressor  discharge  valve port (High 
pressure). 
The pressure in the  system  will 
eventually balance. 
6. If the full charge of 1,0 kg (2.2 Ib) of liquid 
refrigerant  will not enter  the system, then  close  the 
high  pressure  valve 
(No. 2) and open  the low 
pressure  valve 
(No. l), ensuring  that the low 
pressure  gauge does not exceed 
40 psi. 
7. Start  and run the engine  at  1,000-1,500 rev/min 
and allow  refrigerant  to be  drawn  though  the  low 
pressure  valve 
(No. 1) until the full  charge of 
1,0 kg (2.2 Ib) has been drawn into the system. 
8. Close  valve No. 1. 
6, 4-6 
 ST 1398M 
9. Check  the  air  conditioning  system is operating 
satisfactorily  by carrying  out a  prcssurc  test,  as 
described later 
in the Section. 
CAUTION: Do not  overcharge  the air conditioning 
system 
as this  will cause  excessive  head pressure. 
Leak  test 
The following  instructions  refer to an  electronic  type 
refrigerant  leak detector  which is the  safest,  most 
sensitive  and widely  used. 
1. Place the vehicle in a well  ventilated  arca but free 
from  draughts, 
as leakage from the system could  be 
dissipated  without  detection. 
2. Follow the instructions  issued  by the  manufacturer 
of the particular  leak detector  being uscd. Certain 
dctectors have visual  and audible indicators. 
3. Commence  searching for leaks  by passing  the 
deiecioi pietie aiuund aii jwinis and components, 
particularly  on 
the underside, as the  refrigerant  gas 
is  heavier than air. 
4. Insert the probe into an  air  outlet of the 
evaporator.  Switch the air conditioning  blower  on 
and  off at intervals 
of ten  seconds.  Any leaking 
refrigerant  will be gathered 
in by  the  blower  and 
detected. 
15  
						

							182 I AIR CONDITIONING - L.H. & R.H. STEERING 
Ambient 
Temperature 
C OF 
16  60 
26,7 80 
38  100 
433 110 
5. Insert the probe  between the magnetic  clutch and 
compressor  to check  the shaft  seal for leaks. 
6. Check all service  valve conncctions, valve plate, 
head  and base  plate  joints and  back seal plate. 
7.  Check  the  condenser  for  leaks at the  pipe 
connections. 
8. If  any  leaks  are found,  the system  must  be 
depressurised  before  attempting rectification. 
If 
repairs by brazing  are necessary,  the  component 
must 
be removed  from thc vehicle  and all traces of 
refrigerant  expelled before heat  is applied. 
9. After  repairs  check  the  system for leaks  and 
evacuate  prior to charging. 
Compound Gauge High Pressure Readings  Gauge Readings 
kgf/cm2 Ibf/in2 kgf/cm2 Ibflin 
1,05-1,4 15-20 7,O-10,2 100-150 
1,4-1,75 20-25 9,8-13,3 140-190 
1,75-2,1 25-30 11,6-15.8 180-225 
2,l-2,45 30-35 15,l-17,5 215-250 
Pressure test 
1. Fit the charging  and test equipment  as  previously 
2. Start the engine. 
3. Run  the engine  at 1,000 to 1,200 rev/min with  the 
heat  control set  to 
cold (blue) zone,  air distribution 
to the central  position,  recirculation control to 
recirculation and the air conditioning control ON 
with  fan speed  to maximum. 
4.  Note 
thc ambient  air  tcmpcrature  control in the 
immediate  test area 
in front  of the  vehicle,  and 
check  the  high pressure  gauge  readings 
- 
discharge sidc - against  table 1. 
- described. 
Table I 
Test 
1. Place the vehicle  in a ventilated, shaded  area free 
from  excessive  draught, with the doors  and 
windows  open. 
2.  Check  that 
the surface of the  condenser  is not 
restricted  with dirt,  leaves,  flies, etc. 
Do not 
neglect  to check  the surface between  the condenser 
and the  radiator.  Clean as necessary. 
3. Switch on the  ignition  and the  air  conditioner  air 
flow  control.  Check that the blower  is operating 
efficiently  at low,  medium  and high  speeds.  Switch 
off the blower  and the ignition. 
4. Check  that the evaporator  condensate  drains are 
open  and clear. 
5. Check  the tension of the  compressor  driving belt, 
and  adjust 
if necessary. 
6. Inspect  all connections  for  the presence  of 
refrigerant  oil. 
If oil is evident,  check for leaks, and 
rectify  as necessary. 
NOTE:  The compressor  oil is soluble in Refrigerant 
12 and is deposited  when the refrigerant  evaporates 
from  a leak. 
7.  Start the  engine. 
8. Set the  temperature  control  switch to maximum 
cooling  and switch  the air conditioner  blower 
control 
on and  off several  times, checking  that the 
magnetic  clutch on the  compressor  engages and 
releases  each time. 
9. With the temperature  control at  maximum  cooling 
and  the blower  control  at high  speed,  warm up the 
engine  and fast idle  at  1,000 
rev/min. Check the 
sight  glass  for  bubbles 
or foam. The sight  glass 
should  be generally  clear  after  five minutes 
running,  occasional  bubbles being  acceptable. 
Continuous  bubbles  may appear  in a serviceable 
system  on a cool  day, 
or if there  is insufficient  air 
flow  over 
the condenser  at a high  ambient 
temperature. 
10.  Repeat  at  1,800 
rev/min. 
11. Gradually  increase the engine  speed to the high 
12. Check  for frosting  on the  service  valves and 
range, and 
check the sight glass  at intervals. 
evaDorator fins. 
I 7, Close both service ports (turn fully a,,ti-clockwise)/ 
and  close  all valves on the  charging  and test 
equipment.  Disconnect the charging  lines from  the 
compressor. Refit the blanking caps to the 
compressor  valve stems,  port  connections  and 
charging lines. 
i3. Check the nigh pressure pipes and connecrions by 
hand  for  varying temperature. Low temperature 
indicates  a restriction  or blockage  at that  point. 
14.  Switch off  the air conditioning blower and  stop the 
engine. 
satisfactory,  proceed  with the  pressure  test as 
15. If the  air  conditioning  equipment is still  not 
8. Close  the bonnet. 
16 
previously  described in this  section.