GREAT WALL PEGASUS 2006 Service Manual

AC-8Air-Conditioning System
System Component
system component
liquid tankcompressor
condenserHP hoseLP hose
Tightening moment for air-conditioning pipeline

Open-wrench spanner (mm)Tightening moment(N
m)
Threaded
joint of
com-
pressor Threaded
joint
Pressing
plate bolt14
17
Threaded head (mm)
Open-wrench spanner (mm)Tightening moment(N
m) Tightening moment(N
m)
Air-conditioning pipe-lineTightening moment(N
m)
LP hose interface
HP hose interface25
2 35
3
18
1.5
Dr SF SL SK SY SJ
17
19
19
19
22
24
24
27
27
2715
3
15
3
15
3
25~30
30~35
30~35
10
148~12
21~25
24
1425~30
30~35HP hose interfaceevaporator

AC-9Air-conditioning System - General introduction
General introduction
Refrigeration cycle
1. The refrigerant at the lower pressure side is condensed by the
compressor into the HT and HP gaseous refrigerant.
2. These gaseous refrigerant flows into the condenser, where it is
turned into liquid refrigerant.
3. Those liquid refrigerant flows into the liquid tank, where the
liquid refrigerant is stored and filtered so as to satisfy the
requirement of evaporator.
diaschage vent indraft vent
compressor
curent direction
evaporator heat
heat expansionvalve
liquid tank
4. The liquid refrigerant is throttled by the expansion valve to reduce the pressure, so that the liquid refrigerant is turned
into the LT and LP mixture of liquid and gaseous refrigerant.
5. The cold and fog-like refrigerant flows into the evaporator, where it is vaporized with the given heat, which is
absorbed from the hot air flow by the evaporator core. All liquid refrigerants are turned into the gaseous refrigerant
in the evaporator, and only the heated gaseous refrigerant is absorbed into the compressor. Then repeat the above-
mentioned cycling approach.
The refrigerant released from
the evaporator expands and
inflows through the evapora-
tor pipe. During this process,
the refrigerant absorbs the
heat in the air around the ra-
diating rib and pipe and
vaporizes, so that the tem-
perature inside the vehicle
reduces gradually.
The condenser allows the heated gas-
eous refrigerant to release heat to the
cooling air of engine, therefore, the gas-
eous refrigerant is cooled and turned
into liquid state again.
The expansion valve is used
to measure the gaseous re-
frigerant entered into evapo-
rator core, which reduces the
pressure and temperature of
refrigerant gradually.
The liquid tank is used to exhaust
the water in system and to filter
the dust and dunghill. It serves as
the store to store the redundant
refrigerant.
The compressor absorbs the
gaseous refrigerant emitted
from the evaporator and com-
presses it. In doing so, the tem-
perature and pressure of gas-
eous refrigerant increases
rapidly.

AC-10Air-conditioning System - Troubleshooting
Troubleshooting
TroubleReparation approachesPage
Lack of cold airNon-pull-in performance of electromagnetic clutch:
(a) Break of ignition switch and fuse;
(b) Trouble of electromagnetic clutch;
(c) Trouble of A/C switch;
(d) Wiring or grounding trouble;
(e) Lack of refrigerant; and
(f) Trouble of pressure switch.
Abnormal operation of compressor:
(a) Looseness or break of driving belt;
(b) Compressor trouble;
Expansion valve trouble;
Systematic leakage;
Liquid tank fusible plug melting or filtering
screen blocking;
Non-work of air blower:
(a) Failure of A/C switch;
(b) Failure of air blower motor, and
(c) Wiring failure.Change the fuse and check to see whether
there is short circuit;
Check the electromagnetic clutch;
Check the A/C switch;
Repair it as requirement;
Check the refrigerant pressure;
Check the pressure switch;
Adjust or change the driving belt;
Check the compressor;
Check the expansion valve;
Conduct lubricating test for the system
Check the liquid tank;
Check the A/C switch;
Check the air blower motor;
Conduct reparation as requirement.
Inconsecutive
cold airElectromagnetic valve slip
Failure of expansion valve;
Wiring or connecting failure;
Over water content in systemCheck the electromagnetic clutch;
Check the expansion valve;
Make reparation as requirement.
Reclaim the water first, then exhaust the
system to vacuum and inflate in the refrigerant.
Cold air occurs in
high-speed conditionBlocking of radiating face of condenser;
Driving belt slip;
Compressor failure;
Insufficient or redundant refrigerant;
Air existing in systemCheck and wash the condenser
Check and change the driving belt;
Check the compressor;
Check the refrigerant quantity;
Vacuumize the system and inflate
the refrigerant;
Insufficient
cold airCondenser blocking;
Driving belt slip;
Electromagnetic clutch failure;
Compressor failure;
Expansion valve failure;
Insufficient or redundant refrigerant;
Air existing in system;
Redundant compressor lubricant;
Liquid tank blockCheck the condenser;
Check and change the driving belt;
Check the electromagnetic clutch;
Check the compressor;
Check the expansion valve;
Check the refrigerant quantity;
Reclaim the air, then vacuumize the sys-
tem and inflate the refrigerant;
Check the compressor lubricant quantity;
Check the liquid tank
Evaporator blocking or frosting
Air leakage in cooling device or air
pipeline;
Air inlet blocking;
Air blower motor failure;Clean the evaporator radiating rib
or filter;
Make reparation as requirement
Make reparation as requirement
Change the air blower motor.
Page AC-4 to 7
Page AC-12
Page AC-4 to 7
Page AC-11
Page AC-13
Page AC-12
Page AC-16
Page AC-14
Page AC-4 to 7
Page AC-12
Page AC-16
Page AC-4 to 7
Page AC-15
Page AC-12
Page AC-12
Page AC-12
Page AC-16
Page AC-11
Page AC-14
Page AC-18
Page AC-20
Possible causes
Page AC-15
Page AC-13
Page AC-12
Page AC-11
Under-speed cold air

AC-11Air-Conditioning System
Inspection On Refrigerant Quantity
Inspection on Refrigerant Quantity
1. Run the engine at the speed of 1500 r/m or so (the
atmospheric temperature should be above 35
);
2. Start the air-conditioner in the max cold air status for
several minutes;
3. Check the refrigerant quantity.
Watch the observation window on liquid tank.
Dr SF
SL SK SY SJ
liquid tank
liquid tankobservation window
observation window
No.
1
2
3
4
5
6
Symptoms
Refrigerant quantityRepairing approaches
Air bubble occurs in the observa-
tion window
No air bubble in observation win-
dow
No temperature difference between
the inlet and outlet of compressor
Obvious temperature difference be-
tween the inlet and outlet of compressor.
Observation window is in clear status
once the air-conditioner is turned off
There is refrigerant foam on observa-
tion window after the air-conditioner
is turned off, then the observation
window becomes clear.Insufficient
No, normal or redundant
No, or almost no
Normal or redundant
Redundant
NormalCheck to see whether there is leakage with the
gas leakage detector
Refers 3 and 4.
Vacuumize the system and inflate the
refrigerant, then check to see whether there is
leakage with the gas leakage detector.
Refer 5 and 6
Exhaust the redundant refrigerant until the speci-
fied quantity is satisfied.

AC-12Air-Conditioning System
Compressor
Installation of manifold gauge
Remark: Connect the manifold gauge to the auxiliary valve of
compressor.
1. Turn off the manual valve of manifold gauge.
2. Mount the packing hose of manifold gauge on the packing
valve.
Mount the LP hose to the LP packing valve and the HP hose to
HP packing valve. Then screw up the nuts for hose joint by
hand.
Remark: Do not coat the compressor lubricant on the connec-
tion positions.
packing hose
efrigeration system
connected to mani-
fold gauge
connect to compressor
turn offturn offCompressor
On vehicle inspection
1. Mount the manifold gauge;
(see manifold gauge mount)
2. Run the engine at the speed of 1500 r/m or so;
3. Check the compressor according to the following items:
(a) The HP gauge readings under the normal system should
satisfy the specified value of (1.4-1.7)MPa , that of LP
gauge should meet the specified value of (0.15-0.2)MPa .
(b) Whether there is abnormal sound;
(c) Whether there is leakage at the shaft oil seal.
If any problem is found, repair or change the compressor.
4. Check the electromagnetic clutch:
(a) Check to see whether there is lubricant trace on the
pressing plate and rotor;
(b) Check to see whether there is noise or lubricant leakage
at the clutch bearing;
(c) Measure the resistance between the stator coils that is set
between the clutch lead and the grounding lead with the
ohmn meter.
Standard resistance:
SL SK SJ
(3.2
.2)
Ω
Dr SF SY
(3.5
.2)Ω
In case the requirement is not satisfied, change the compressor.

AC-13Air-Conditioning System
Compressor
Disassemble of compressor
1. Run the engine in the idle status for ten minutes under
the air-conditioning situation;
2. Turn off the engine;
3. Disconnect the cathode lead from the storage cell;
4. Disconnect the electromagnetic clutch lead from the
matching wire;
5. Exhaust the refrigerant from the refrigeration system;
6. Disconnect the two hoses from the auxiliary valve of
compressor;
Cover the opening joint with cork right away to prevent the wet
gas entering in to the system.
7. Tear down the compressor:
(a) Tear down the fan cover;
(b) Loosen the driving belt;
(c) Tear down the fixing bolts of compressor bracket and the
compressor.
Mount of compressor
1. Mount the compressor with fixing bolts;
Tightening moment
(25-30)N
m
2. Mount the driving belt correctly;
Requirement for belt tension: the tension belt is allowed
to reduce (9-13)mm under 98N after the compressor
runs for five minutes;
3. Connect the two hoses to the auxiliary valve of
compressor;
Tightening moment
(see page AC-8)
4. Connect the clutch lead to the matching wire;
5. Connect the cathode lead of storage cell to the storage
cell, and
6. Vacuumize the system and inflate the refrigerant:
Vacuum time:
Dr SL SK SF SJ
Vacuumize for 20min and main-
tain the pressure for 30min;
SY
Vacuumize for 30min and maintain for 30min
Inflated refrigerant quantity:
Dr
(600-650)g
SL
700
0g
SK SJ
560
0g
SF
(700-720)g
SY
850
0gcorrect incorrect incorrect
98N

AC-14Air-Conditioning System
Liquid Tank
Liquid Tank
Check to see whether there is leakage in observation window,
fusible plug and joints;
Conduct the inspection with the gas leakage detector and, if
necessary, repair or change the liquid tank.
Dismantle of Liquid Tank
1. Exhaust the refrigerant;
2. Tear down the two liquid pipes from the liquid tank;
Remark: the opened joint should be plugged with cork so as to
prevent the humid air from entering into the system.
3. Tear down the liquid tank from the tank bracket.
Mount of Liquid Tank
1. Mount the liquid tank on the liquid tank bracket;
Remark: the cover of joint should not be take down before
connecting the pipe;
2. Connect the two liquid pipes to the liquid tank;
Tightening moment
(See page AC-8)
3. Vacuumize the system and inflate the refrigerant in;
Vacuumizing time:
Dr SL SK SF SJ
Vacuumize for 20 min and main-
tain the pressure for 30min;
SY
Vacuumize for 30 min and maintain the pres-
sure for 30min.
4.
Dr
(600-650)g
SL
700
0g
SK SJ
560
0g
SF
(700-720)g
SY
850
0g
liquid pipe
condenser
liquid tank
liquid pipe
liquid pipe liquid pipe
liquid tankcondenser
SL SK SY SJ
Dr SF

AC-15Air-Conditioning System
Condenser
Condenser
Condenser dismantle
1. Check the radiating ribs of condenser to see whether
there is blocking or damage;
if the radiating rib is blocked, wash it with water and dry it with
compressed air.
Notice: be careful not to damage the radiating rib;
2. Check the condenser joint to see whether there is leakage;
Make reparation as requirement;
Condenser disassembly
1. Exhaust the refrigerant;
2. Tear down the median mesh and the bonnet lock bracket;
3. Disconnect the outlet hose from the entrance joint of
condenser;
4. Tear down the liquid pipe from the outlet of liquid tank;
Remark: the opened joint should be plugged with cork so as to
prevent the humid air from entering into the system.
5. Tear down the condenser:
Tear down the two bolts.
Condenser mount
1. Mount the condenser
Screw on the two bolts so that the rubber washer contacts the
mounting flanges correctly.
2. Connect the liquid pipe to the liquid tank and the outlet
hose to the condenser.
Tightening moment
(See page AC-8)
3. Mount the median mesh and the bonnet lock bracket;
4. vacuumize the air-conditioning system;
Vacuumizing time:
Dr SL SK SF SJ
vaccumize for 20min and main-
tain the pressure for 30min;
SY
vaccumize for 30min and maintain the pres-
sure for another 30min.
5. Inflate the refrigerant in the air-conditioning system and
check to see whether there is air leakage:
Dr
(600-650)g

SL
700
0g
SK SJ
560
0g
SF
(700-720)g
SY
850
0g
liquid pipe
condenser
liquid tank
liquid pipe
condenser
liquid tank
SL SK SY SJ Dr SF
liquid pipe outlet hose
liquid pipe

AC-16Air-Conditioning System
Refrigeration Device
Refrigeration device
On-vehicle inspection on expansion valve
1. Check the gaseous refrigerant quantity in the refrigeration
cycle;
2. Mount the manifold gauge;
(see Page AC-12)
3. Run the engine;
Run the engine at a speed of 2000 r/m for five minutes.
4. Check the expansion valve;
If the expansion valve is blocked, the LP readings will reduce
to 0 kPa, otherwise, the valve is normal.
Disassembly of Refrigeration Device
1. Disconnect the cathode lead from the storage cell;
2. Exhaust the refrigerant;
3. Tear down the suction pipe from the entrance joint of
refrigeration device;
4. Tear down the outlet pipe from the entrance joint of
refrigeration device;
Remark: the opened joint should be sealed with the cork to
prevent the humid air from entering into the system.
5. Tear down the insulation rings from the inlet and outlet
joints.
6. Tear down the right glove box (SY rear air-conditioner:
tear down the interior trim panel at left rear side).
7. Disconnect the plugging element;
8. Tear down the refrigeration device;
Tear down the three nuts.
refrigeration device
SYinterior trim panel
at left rear side
rear evaporator

AC-17Air-Conditioning System
Refrigeration Device
evaporator housing
Dr SF
SL SK SY SJ
evaporator housing
residual liquid pipe
heat-sensitive
resistance
pressure switch
evaporator core
expansion valve
heat-sensitive
resistanceevaporator upper
housingevaporator core
evaporator lower
housingexpansion valve HPpressure rubber
LPpressure rubber
HP/LP pressure rubber