SECTION : 7B
MANUAL CONTROL HEATING, VENTILATION
AND AIR CONDITIONING SYSTEM
CAUTION : Disconnect the negative battery cable before removing or installing any electrical unit or when a tool
or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable will help
prevent personal injury and damage to the vehicle. The ignition must also be in LOCK unless otherwise noted.
TABLE OF CONTENTS
SPECIFICATIONS7B–2 . . . . . . . . . . . . . . . . . . . . . . . . . .
General Specifications 7B–2. . . . . . . . . . . . . . . . . . . . .
Fastener Tightening Specifications 7B–2. . . . . . . . . . .
SPECIAL TOOLS7B–3 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Tools Table 7B–3. . . . . . . . . . . . . . . . . . . . . . . .
SCHEMATIC AND ROUTING DIAGRAMS7B–6 . . . . .
A/C System – Typical 7B–6. . . . . . . . . . . . . . . . . . . . . .
Manual Control A/C Diagram 7B–7. . . . . . . . . . . . . . . .
DIAGNOSIS7B–8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL DIAGNOSIS 7B–8. . . . . . . . . . . . . . . . . . . . . .
Testing the Refrigerant System 7B–8. . . . . . . . . . . . . .
Insufficient Cooling ”Quick Check” Procedure 7B–8. .
A/C Performance Test 7B–9. . . . . . . . . . . . . . . . . . . . . .
Pressure–Temperature Relationship of
R–134A 7B–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Leak Testing Refrigerant System 7B–11. . . . . . . . . . . .
V5 SYSTEM AIR CONDITIONING DIAGNOSIS 7B–12
Insufficient Cooling Diagnosis 7B–12. . . . . . . . . . . . . .
SYMPTOM DIAGNOSIS 7B–16. . . . . . . . . . . . . . . . . . . .
Pressure Test Chart (R–134A System) 7B–16. . . . . .
Low and High Side Pressure Relationship
Chart 7B–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MAINTENANCE AND REPAIR7B–19 . . . . . . . . . . . . . .
ON–VEHICLE SERVICE 7B–19. . . . . . . . . . . . . . . . . . . .
GENERAL A/C SYSTEM SERVICE
PROCEDURES 7B–19. . . . . . . . . . . . . . . . . . . . . . . . . .
O–Ring Replacement 7B–19. . . . . . . . . . . . . . . . . . . . .
Handling Refrigerant 7B–19. . . . . . . . . . . . . . . . . . . . . .
Handling of Refrigerant Lines and Fittings 7B–19. . . .
Maintaining Chemical Stability in the Refrigeration
System 7B–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Discharging, Adding Oil, Evacuating, and Charging
Procedures for A/C System 7B–20. . . . . . . . . . . . . .
SERVICEABLE COMPONENTS 7B–23. . . . . . . . . . . . . Components Used In Non–A/C Systems 7B–23. . . . .
A/C Pressure Transducer 7B–24. . . . . . . . . . . . . . . . . .
A/C Compressor Relay 7B–24. . . . . . . . . . . . . . . . . . . .
Air Filter 7B–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A/C Expansion Valve 7B–25. . . . . . . . . . . . . . . . . . . . . .
A/C High–Pressure Pipe Line 7B–26. . . . . . . . . . . . . . .
Evaporator Core 7B–29. . . . . . . . . . . . . . . . . . . . . . . . . .
A/C Suction Hose Assembly 7B–30. . . . . . . . . . . . . . .
A/C Discharge Hose Compressor to
Condenser 7B–31. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Receiver–Dryer 7B–32. . . . . . . . . . . . . . . . . . . . . . . . . . .
Compressor 7B–33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Condenser 7B–35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
UNIT REPAIR 7B–37. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
COMPONENT LOCATOR 7B–37. . . . . . . . . . . . . . . . . . .
V5 Compressor 7B–37. . . . . . . . . . . . . . . . . . . . . . . . . . .
V5 AIR CONDITIONING COMPRESSOR
OVERHAUL 7B–38. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Clutch Plate and Hub Assembly 7B–38. . . . . . . . . . . .
Clutch Rotor and Bearing 7B–40. . . . . . . . . . . . . . . . . .
Clutch Coil 7B–42. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shaft Seal Replacement 7B–44. . . . . . . . . . . . . . . . . . .
Control Valve Assembly 7B–46. . . . . . . . . . . . . . . . . . .
Rear Head, Gasket, Valve Plate, Reed Plate,
and O–ring 7B–47. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder to Front Head O–ring 7B–48. . . . . . . . . . . . . .
Leak Testing (External) 7B–50. . . . . . . . . . . . . . . . . . . .
GENERAL DESCRIPTION AND SYSTEM
OPERATION7B–51 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL INFORMATION 7B–51. . . . . . . . . . . . . . . . . .
The V5 A/C System 7B–51. . . . . . . . . . . . . . . . . . . . . . .
System Components – Functional 7B–51. . . . . . . . . .
System Components – Control 7B–52. . . . . . . . . . . . .
V5 Compressor – General Description 7B–52. . . . . . .
V5 Compressor – Description of Operation 7B–52. . .
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.
MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 17
DAEWOO V–121 BL4
Test ResultsRemedy Probable Cause Related Symptioms
Suction pressure ab-
normally highSuction pressure is lowered
when the condenser is
cooled by water.Excessive refrigerant in the sys-
tem.Recover, evacuate, and re-
charge the system.
High and low pressure are
equalized as soon as the
compressor is stopped and
both gauges fluctuate while
the compressor is running.Faulty gasket.Repair or replace the com-
pressor.
Faulty high–pressure valve. (V5
compressor only)
Foreign particles stuck in the
high–pressure valve. (V5 com-
pressor only)
Suction and dis-
charge pressure ab-
ll hi h
Reduced airflow through
the condenser.Clogged condenser or radiator
fins.Clean the condenser and
the radiator.
g
normally highRadiator cooling fans working im-
properly.Check the voltage and the
radiator cooling fan rpm.
Check the fan direction.
Condenser is excessively
hot.Excessive refrigerant in the sys-
tem.Recover, evacuate, and re-
charge the system.
Suction and dis-
charge pressure ab-
normally lowLow–pressure hose and
metal end areas are cooler
than the evaporator.Clogged or kinked low–pressure
hose.Repair or replace the low–
pressure hose.
Temperature around the ex-
pansion valve is low
compared to that around
the receiver–dryer.Clogged high–pressure line.Repair or replace the high–
pressure line.
Refrigerant leaksThe compressor clutch is
dirty.Leaking compressor shaft seal.Repair or replace the com-
pressor.
The compressor bolts are
dirty.Leaking around a compressor
housing bolt.Tighten the bolt(s) or re-
place the compressor.
The compressor gasket is
wet with oil.Leaking compressor gasket.Repair or replace the com-
pressor.
MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 21
DAEWOO V–121 BL4
Refrigerant Recovery
Important : Use only a refrigerant tank that is designed for
the charging station in use. The unit’s overfill limitation
mechanism is calibrated specifically for use with this tank.
The tank’s valves are also manufactured specifically for
this unit.
1. Attach the high–side hose with the quick disconnect
coupler to the high–side fitting of the vehicle’s A/C
system.
2. Open the coupler valve.
3. Attach the low–side hose with the quick disconnect
coupler to the low–side fitting of the vehicle’s A/C
system.
4. Open the coupler valve.
5. Check the high–side and the low–side gauges on
the unit’s control panel in order to ensure that the
A/C system has pressure. If there is no pressure,
there is no refrigerant in the system to recover.
Important : If there is no refrigerant in the system, do not
continue with the recovery operation which would, under
this condition, draw air into the recovery tank.
6. Open both the high–side and the low–side valves.
7. Open the gas and the liquid valves on the tank.
8. Drain any oil that may be in the oil separator.
9. Close the oil drain valve.
10. Plug the unit into the proper voltage outlet.
11. Turn on the main power switch.
Notice : Never reuse refrigerant oil. Damage to the A/C
system may result from such reuse. Dispose of the refrig-
erant oil properly.
12. Begin the recovery process. Refer to the manufac-
turer ’s instructions for the charging station in use.
Important : Some A/C system polyalkaline glycol (PAG)
lubricating oil may be removed with the refrigerant during
recovery. The amount of oil removed varies. A charging
station separates the oil from the refrigerant and provides
a means of determining how much oil was removed. Re-
place the same amount of oil when recharging the system.
Refer to the manufacturer’s instructions for the charging
station in use.
13. Wait 5 minutes, then check the control panel low–
side gauge. If the A/C has maintained vacuum, the
recovery is complete.
14. If the low–side gauge pressure rises above zero,
there is more refrigerant in the system. Recover the
additional refrigerant. Repeat this step until the sys-
tem maintains vacuum for 2 minutes.
Important : If the control indicator shows that the refriger-
ant tank is full during the recovery process and the unit
shuts off, install an empty unit tank to store the refrigerant
needed for steps later in the procedure. Do not use any
other type of tank.
Evacuation
The unit tank must contain a sufficient amount of R–134a
refrigerant for charging. Check the amount of refrigerant
in the tank. If there is less than 3.6 kg (8 pounds) of refrig-
erant, add new refrigerant to the tank. Refer to the
manufacturer ’s instructions for adding refrigerant.
1. Verify that the high–side and the low–side hoses
are connected to the A/C system. Open both the
high–side and the low–side valves on the unit’s
control panel.
2. Open both the gas and the liquid valves on the
tank.
Important : Refer to the manufacturer’s instructions for
the charging station in use. It is necessary to evacuate the
system before recharging it with new or recycled refriger-
ant.
3. Start the vacuum pump and begin the evacuation
process. Non–condensable gases (mostly air) are
vented from the tank automatically during the re-
cycling process. You may hear the pressure being
released.
4. Check for leaks in the system. Refer to the
manufacturer ’s instructions for the charging station
in use.
Important : Change the vacuum pump oil frequently. Re-
fer to the manufacturer’s instructions for the charging sta-
tion in use.
A/C System Oil Charge Replenishing
Any oil removed from the A/C system during the recovery
process must be replenished at this time.
1. Use the correct graduated bottle of PAG oil for the
R–134a system.
Important:
S Keep the oil bottles tightly capped at all times to
protect the oil from moisture and contamination.
S You must have an A/C system vacuum for this op-
eration. Never open the oil injection valve while
there is positive pressure in the A/C system. This
will result in oil blowback through the bottle vent.
S Never let the oil level drop below the pickup tube
while charging or replenishing the system, as this
will allow air into the A/C system.
2. Refer to the manufacturer’s instructions for the
charging station in use. Add the proper amount of
PAG oil to the system.
3. Close the valve when the required oil charge has
been pulled into the system.
Charging
Important : Evacuate the A/C system before charging.
1. Close the low–side valve on the control panel.
2. Open the high–side valve on the control panel.
3. Refer to the manufacturer’s instructions for the
charging station in use.
4. Enter the amount of refrigerant needed to charge
the A/C, making sure to use the correct system of
measurement, i.e. kilogram (kg) or pound (lb).
5. Begin the charging process.
MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 37
DAEWOO V–121 BL4
UNIT REPAIR
COMPONENT LOCATOR
V5 COMPRESSOR
1. Rear Head Compressor
2. Control Valve O–Ring
3. Rear Head Gasket
4. Valve Plate
5. Suction Reed
6. Clutch Coil
7. Retaining Ring
8. Drive Plate Clutch
9. Pulley Bearing
10. Clutch Hub Key
11. Shaft Nut
12. Seal Retaining Ring
13. Shaft Lip Seal
14. Shaft Seal O–Ring
15. Compressor Housing16. Compressor Control Valve
17. Pulley Bearing–to–Head Retaining Ring
18. Rotor Pulley
19. Through–Bolt
20. Through–Gasket
21. Compressor Housing–to–Cylinder O–Ring
22. Shaft and Guide Pin Assembly Cylinder
23. Rear Head O–Ring
24. Thrust Washer
25. Race
26. Bearing
27. Oil Drain Plug
28. Clutch and Hub Keyway
29. Compressor Shaft
MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 47
DAEWOO V–121 BL4
REAR HEAD, GASKET, VALVE
PLATE, REED PLATE, AND O–RING
Tools Required
J–34993 Cylinder Alignment Rods
Removal Procedure
1. Recover the refrigerant. Refer to ”Discharging, Add-
ing Oil, Evacuating, and Charging Procedures for
A/C System” in this section.
2. Discharge the A/C system. Refer to ”Discharging,
Adding Oil, Evacuating, and Charging Procedures
for A/C System” in this section.
3. Remove the compressor. Refer to ”Compressor” in
this section.
4. Drain the oil from compressor into a suitable con-
tainer. Measure and record the amount of oil
drained from the compressor. Discard the used oil.
5. Remove the clutch plate and hub assembly. Refer
to ”Clutch Plate and Hub Assembly” in this section.
6. Remove the clutch rotor and bearing. Refer to
”Clutch Rotor and Bearing” in this section.
7. Remove the clutch coil. Refer to ”Clutch Coil” in
this section.
8. Remove the compressor through–bolts. Remove
and discard the gaskets.
9. Using a wooden block and a plastic–headed ham-
mer, tap around the edge of the rear head to disen-
gage the head from the compressor cylinder. Sepa-
rate the rear head, the head gasket, the rear valve
plate, the suction reed plate, and the cylinder–to–
rear head O–ring. Discard the head gasket and the
O–ring.
Installation Procedure
1. Place the rear head on a clean, flat surface. Posi-
tion the head with the control valve at the 6 o’clock
position.
2. Install the cylinder alignment rods J–34993 in the
mounting holes at the 11 o’clock and the 5 o’clock
positions.
3. Install the head gasket over the cylinder alignment
rods J–34993 with the elongated hole at the upper
left pin (the 11 o’clock position).
4. Install the rear head valve plate over the guide pins
with the elongated hole at the upper left pin. Lower
the rear head valve plate into place.
5. Install the suction reed plate over the cylinder align-
ment rods J–34993. Remove the alignment rod at
the 5 o’clock position.
6. Lubricate the cylinder to the new rear head O–ring
with clean polyalkaline glycol (PAG) refrigerant oil.
7. Install the O–ring in the cylinder O–ring groove. The
O–ring seal surface of the head may be lubricated
to ease assembly.
7B – 48IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
8. With the O–ring in place on the rear of the cylinder
assembly, locate the relief boss for the compressor
guide pin at the 6 o’clock position, directly above
the hole in the side of the rear head. Carefully lower
the cylinder and the front head assembly over the
guide pin to the rear head.
9. Press the cylinder and the compressor housing as-
sembly down onto the rear head using both hands.
10. Add the new through–bolt gasket to the through–
bolts and install it into the compressor assembly.
Four of the through–bolts must thread into the rear
head before removing the alignment rod.
Tighten
Alternately tighten the through–bolts in progressive
torque sequence to 10 NSm (89 lb–in).
11. Add new PAG refrigerant oil as determined in Step
1 of Removal Procedure.
12. Place the shaft nut on the shaft and rotate the com-
pressor shaft several times.
13. Perform a leak test on the compressor. Refer to
”Leak Testing (External)” in this section.
14. Install the clutch coil. Refer to ”Clutch Coil” in this
section.
15. Install the clutch rotor and bearing. Refer to ”Clutch
Rotor and Bearing” in this section.
16. Install the clutch plate and hub assembly. Refer to
”Clutch Plate and Hub Assembly” in this section.
17. Install the compressor. Refer to ”Compressor” in
this section.
18. Evacuate and recharge the A/C system. Refer to
”Discharging, Adding Oil, Evacuating, and Charging
Procedures for A/C System” in this section.
CYLINDER–TO–FRONT HEAD
O–RING
Tools Required
J–34993 Cylinder Alignment Rods
J–35372 Support Block
Removal Procedure
1. Recover the refrigerant. Refer to ”Discharging, Add-
ing Oil, Evacuating, and Charging Procedures for
A/C System” in this section.
2. Remove the compressor. Refer to ”Compressor” in
this section.
3. Drain the oil from compressor into a suitable con-
tainer. Measure and record the amount of oil
drained from the compressor. Discard all used oil.
4. Remove the clutch plate and hub assembly. Refer
to ”Clutch Plate and Hub Assembly” in this section.
5. Remove the clutch rotor and bearing. Refer to
”Clutch Rotor and Bearing” in this section.
6. Remove the clutch coil. Refer to ”Clutch Coil” in
this section.
MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 49
DAEWOO V–121 BL4
7. Remove and discard the shaft seal parts. Refer to
”Shaft Seal Replacement” in this section.
8. Remove the compressor through–bolts. Remove
and discard the gaskets.
9. Using a wooden block and a plastic–headed ham-
mer, tap the compressor housing at the mounting
locations to disengage the housing from the com-
pressor cylinder.
Important : Note the assembly sequence of the thrust
washer and bearing for ease of assembly.
10. Remove the thrust washer and the bearing.
11. Remove and discard the compressor housing–to–
cylinder O–ring.
Installation Procedure
1. Rest the rear head on the support block J–35372.
Locate the control valve at the 6 o’clock position.
2. Install cylinder alignment rod J–34993 through the
11 o’clock and the 5 o’clock bolt holes.
3. Lubricate the new cylinder–to–compressor housing
O–ring with clean polyalkaline glycol (PAG) oil.
4. Install the new O–ring in the cylinder O–ring
groove.
5. Install the thrust washer and bearing in the same
order as they were removed.
6. Align the guide pin recess in the compressor hous-
ing with the guide pin. Press down on the compres-
sor housing with both hands to force it over the O–
ring on the cylinder assembly.
7. Add a new through–bolt gasket to the through–bolts
and install it into the compressor assembly. Four
through–bolts must thread into the rear head before
removing the guide pins.
Tighten
Alternately tighten the through–bolts in progressive
torque sequence to 10 NSm (89 lb–in).
8. Install a new shaft seal. Refer to ”Shaft Seal Re-
placement” in this section.
9. Add new PAG oil equal to the amount drained in
Step 3.
10. Install the clutch coil. Refer to ”Clutch Coil” in this
section.
11. Install the clutch rotor and bearing. Refer to ”Clutch
Rotor and Bearing” in this section.
12. Install the clutch plate and hub assembly. Refer to
”Clutch Plate and Hub Assembly” in this section.
13. Perform a leak test on the compressor. Refer to
”Leak Testing (External)” in this section.
14. Install the compressor. Refer to ”Compressor” in
this section.
15. Evacuate and recharge the A/C system. Refer to
”Discharging, Adding Oil, Evacuating, and Charging
Procedures for A/C System” in this section.