Page 2006 of 2643
7B – 4IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
J–9625–A
Pressure Testing
Connector
J–23128–A
Seal Seat Remover
and Installer
J–35372
Support Block
J–33011
O–Ring Installer
J–33013–B
Hub and Drive Plate
Remover and Installer
J–34993
Cylinder
Alignment Rods
J–33017
Pulley Rotor and
Bearing Installer
J–33019
Bearing Staking
Tool Set
Includes:
J–33019–1
Bearing Staking Guide
J–33019–2
Bearing Staking Pin
J–33020
Pulley Puller
J–34614
Shaft Seal Protector
Page 2007 of 2643
MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 5
DAEWOO V–121 BL4
J–33022
Shaft Nut Socket
J–33023–A
Puller Pilot
J–33024
Clutch Coil
Installer Adapter
J–33025
Clutch Coil Puller Legs
J–34992
Compressor
Holding Fixture
J–33027
Clutch Hub
Holding Tool
Page 2008 of 2643
7B – 6IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
SCHEMATIC AND ROUTING DIAGRAMS
A/C SYSTEM – TYPICAL
1. Compressor
2. Pressure Relief Valve
3. Condenser4. Receiver–Dryer
5. Evaporator
6. Expansion Valve
Page 2009 of 2643
MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 7
DAEWOO V–121 BL4
MANUAL CONTROL A/C DIAGRAM
Page 2010 of 2643
7B – 8IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
DIAGNOSIS
GENERAL DIAGNOSIS
TESTING THE REFRIGERANT
SYSTEM
If you suspect a problem in the refrigerant system, check
for the following conditions:
1. Check the outer surfaces of the radiator and the
condenser cores to be sure that the airflow is not
blocked by dirt, leaves, or other foreign material.
Check between the condenser and the radiator, as
well as all outer surfaces.
2. Check for restrictions or kinks in the condenser
core, the hoses, and the tubes.
3. Check the operation of the blower fan.
4. Check all the air ducts for leaks or restrictions. Low
airflow rate may indicate a restricted evaporator
core.
5. Check for slippage of the compressor clutch.
6. Check the drive belt tension.
INSUFFICIENT COOLING ”QUICK
CHECK” PROCEDURE
Perform the following ”hand–feel” procedure to get a quick
idea of whether the A/C system has the proper charge of
Refrigerant–134a. The air temperature must be above
21°C (70°F) for most models.
1. Warm up engine. Run the engine at idle.
2. Open the hood and all the doors.
3. Turn the A/C switch ON.
4. Set the temperature control to the full cold position.
5. Set the blower speed switch on the maximum
speed setting.
6. ”Hand–feel” the temperature of the evaporator out-
let pipe. The pipe should be cold.
7. Check for other problems. Refer to ”Testing the Re-
frigerant System” in this section.
8. Leak check the system. Refer to ”Leak Testing the
Refrigerant System” in this section. If you find a
leak, discharge the system and repair the leak as
required. After completing the repair, evacuate the
system and charge it.
9. If there is no leak, refer to ”Insufficient Cooling
Diagnosis” in this section.
Page 2011 of 2643
MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 9
DAEWOO V–121 BL4
A/C PERFORMANCE TEST
RELATIVE
HUMIDITY
( % )AMBIENT AIR
TEMPERATURELOW SIDE
PRESSUREENGINE
SPEED
(RPM)CENTER DUCT
AIR
TEMPERATUREHIGH SIDE
PRESSURE
°C°FPsiKpa°C°FPsiKpa
2170261797451601103
2027812416520008462121462
3290261799482771910
381003322814573332296
2170261797451601103
3027812416520008462201517
32902718610502831951
381003423415593492406
217026179846162111 7
4027812617920009482271565
32902920011522952034
381003725517633642510
217026179846162111 7
5027812617920009482351620
32903222113553042096
381007149019663802620
2170271868461651138
6027812617920009482461696
32903423415593242234
381004430322723932710
2170271869481711179
70278128193200010502601793
32903624816613302275
381004732424754012765
2170271869481781227
80278130207200012542661834
32903725517633392337
2170271869481781227
90278130207200012542721875
32903826218643402344
* Test Conditions : Doors & hood opened, A/C ON, Recirculation mode, Full Cool with maximum Blower speed, No Sun-
light, Wind velocity at 8km/h (5 mph).
Page 2012 of 2643
7B – 10IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
PRESSURE–TEMPERATURE RELATIONSHIP OF R–134A
Temperature
°C (°F)*Pressure
kPa (psi)*Temperature
°C (°F)*Pressure
kPa (psi)*
–8 (17.6)113.1 (16.4)9 (48.2)296.2 (43.0)
–7 (19.4)121.5 (17.6)10 (50.0)309.6 (44.9)
–6 (21.2)130.2 (18.9)15 (59.0)383.7 (55.7)
–5 (23.0)139.1 (20.2)20 (68.0)467.7 (67.8)
–4 (24.8)148.4 (21.5)25 (77.0)567.5 (82.3)
–3 (26.6)157.9 (22.9)30 (86.0)667.8 (96.9)
–2 (28.4)167.6 (24.3)35 (95.0)785.6 (113.9)
–1 (30.2)177.8 (25.8)40 (104.0)916.4 (133.0)
0 (32.0)188.2 (27.3)45 (113.0)1 062.2 (154.0)
1 (33.8)198.8 (28.8)50 (122.0)1 222.1 (177.2)
2 (35.6)209.9 (30.4)55 (131.0)1 398.2 (202.8)
3 (37.4)221.2 (32.1)60 (140.0)1 589.6 (230.5)
4 (39.2)232.9 (33.8)65 (149.0)1 799.0 (260.9)
5 (41.0)245.0 (35.5)70 (158.0)2 026.6 (293.9)
6 (42.8)257.4 (37.3)75 (167.0)2 272.2 (329.5)
7 (44.6)269.8 (39.1)80 (176.0)2 544.0 (369.0)
8 (46.4)282.9 (41.0)––
* All calculated values are rounded to one decimal place.
Evaporator Range: From –7 to 7°C (19.4 to 44.6°F), the temperatures represent the gas temperatures inside the coil
and not on the coil surfaces. Add 2 to 6°C (4 to 11°F) to the coil and air–off temperatures.
Condenser Range: From 45 to 70°C (113°to 158°F), the temperatures are not ambient. Add 19 to 22°C (34 to 40°C)
to the ambient temperatures for proper heat transfer. Then refer to the pressure chart.
Example:
32°C (90°F) Ambient temperature + 22°C (40°F) = 54°C (130°F)
Condenser temperature, which yields 1 379 kPa (200 psi), based on 50 km/h (31 mph) airflow.
Page 2013 of 2643
MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 11
DAEWOO V–121 BL4
LEAK TESTING REFRIGERANT
SYSTEM
Test for leaks whenever you suspect a refrigerant leak in
the system. You should also test for leaks whenever you
perform a service operation which results in disturbing the
lines or the connections. Leaks are commonly found at the
refrigerant fittings or at the connections. Leaks are com-
monly caused by the following problems:
S Improper torque.
S Damaged O–ring seals.
S Dirt or lint on the O–ring seals.
Liquid Leak Detectors
Use a liquid leak detector solution on locations such as fit-
tings. Apply the solution to the area in question with the
swab that is supplied with the solution. Look for bubbles
to appear. This will indicate the existence and the location
of any leak.
For areas where this is not practical, such as sections of
the evaporator and the condenser, an electronic leak de-
tector is more useful.
Electronic Leak Detectors
Follow the manufacturer’s instructions for calibration, op-
eration, and maintenance of an electronic leak detector.
Battery condition is especially important to the accuracy
of a portable model. Set the detector to R–134a before be-
ginning the test.
Notice : Electronic leak detectors are sensitive to wind-
shield washing solutions, solvents and cleaners, and cer-
tain vehicle adhesives. Surfaces must be clean to prevent
false readings. Make sure that all surfaces are dry to pre-
vent damage to the detector.
General Testing Instructions
1. Follow the entire path of the refrigerant system.
2. Completely circle each joint at 25 to 50 mm (1 to 2
inches) per second.
3. Hold the probe tip within 6 mm (1/4 inch) of the sur-
face.4. Do not block the air intake.
5. The audible tone changes from 1 to 2 clicks per
second into a solid alarm if there is a leak. Adjust
the balance control to maintain 1 to 2 clicks per
second.
6. Test all of the following areas, even after one leak
has been confirmed:
S Evaporator inlet and outlet.
S Receiver–drier inlet and outlet.
S Condenser inlet and outlet.
S Brazed and welded areas.
S Damaged areas.
S Hose couplings.
S Compressor rear head.
S All fittings and joints.
Testing Service Ports/Access Valves
The sealing caps provide protection for the service ports.
Make sure that these caps are not missing or loose. Al-
ways use the correct cap for each port.
Testing the Evaporator Core
Leaks in the evaporator core are difficult to find. Test the
evaporator core using the following procedure:
1. Run the blower fan at the maximum speed setting
for at least 15 minutes.
2. Turn the blower OFF.
3. Wait for 10 minutes.
4. Remove the blower motor resistor. Refer to Section
7A, Heating and Ventilation System.
5. Insert the leak detector probe as close as possible
to the evaporator core. The detector will indicate a
leak with a solid alarm.
6. Use a flashlight to search for refrigerant oil on the
core surface.
Testing the Compressor Shaft Seal
1. Blow shop air behind and in front of the compressor
clutch/pulley for at least 15 seconds.
2. Wait 1 to 2 minutes.
3. Probe the area in front of the pulley. If the detector
emits a solid alarm, there is a leak.
