2004 DAEWOO LACETTI cooling

7A – 26IHEATING AND VENTILATION SYSTEM
DAEWOO V–121 BL4
Installation Procedure
1. Install the left heater hose to the coolant inlet line
fitting. Slide the end of the heater hose over the
coolant fitting until the hose is seated.
2. Install the right heater hose to the fitting below the
intake manifold. Slide the end of the heater hose
over the fitting until it is seated.
3. Install and seat the other end of each heater hose.
4. Compress and slide the spring clamps into position
on the heater hoses and release the tension.
5. Fill the cooling system.
6. Check the hoses for leaks.
7. Lower the vehicle.
HEATER CORE
(Left–Hand Shown, Right–Hand Drive Similar)
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the instrument panel. Refer to Section 9E,
Instrumentation/Drive Information.
3. Recover the refrigerant.
4. Remove the heater/air distributor case assembly.
Refer to ”Heater/air distributor case assembly” in
this section.
5. Remove the wiring harness and electrical connec-
tors from the heater/air distributor case assembly.
6. Remove the screws that connect the heater core
housing and the evaporator housing.
7. Separate the sponge from heater/air distributor
case assembly.
8. Remove the heater core cover screws from the
heater core housing.
9. Remove the heater core.

HEATING AND VENTILATION SYSTEM 7A – 27
DAEWOO V–121 BL4
Installation Procedure
1. Install the heater core into the case.
2. Install the screws on the heater core housing.
Tighten
Tighten the heater core cover screws to 1.2 NSm (11
lb–in).
3. Install the sponge onto the heater/air distributor
case assembly.
4. Install the screws that connect the heater core
housing and the evaporator housing.
Tighten
Tighten the screws to 1.2 NSm (11 lb–in).
5. Connect the wiring harness and electrical connec-
tors.
6. Install the heater/air distributor case assembly.
7. Install the instrument panel.
8. Fill the cooling system.
9. Evacuate and recharge the refrigerant.
10. Connect the negative battery cable.

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 – 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.

7B – 12IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
V5 SYSTEM AIR CONDITIONING DIAGNOSIS
INSUFFICIENT COOLING DIAGNOSIS
Test Description
The numbers below refer to steps on the diagnostic table.
13. See the Important below.
32. See the Important below.Important : Perform this test under garage conditions with
the air temperature at 21–32°C (70–90°F), and no sun
load. Follow this test carefully for accurate results.
Important : Perform this test exactly as described to ob-
tain accurate results.
Step
ActionValue(s)YesNo
1Record the customer’s complaint.
Can you verify the customer’s complaint?–Go to Step 2System OK
21. Check the A/C fuse.
2. Check the blower fan operation.
3. Check the engine cooling fan operation.
4. Check the A/C compressor belt.
5. Check the A/C condenser for restricted airflow.
6. Check the clutch coil connection.
7. Repair or replace any components as needed.
8. Check the discharge air temperature with the
A/C turned ON.
Is the discharge air temperature normal?At least 7°C
(12°F) below
ambient air
temperatureSystem OKGo to Step 3
31. Turn the ignition switch to LOCK.
2. Connect the high– and the low–pressure
gauges.
Are both pressures within the value specified?69–345 kPa
(10–50 psi)Go to Step 4Go to Step 5
41. Check the A/C system for leaks.
2. Repair any refrigerant leaks as needed.
3. Recover, evacuate, and recharge the A/C sys-
tem.
4. Observe the two pressure gauges.
Are both pressures above the value specified?345 kPa
(50 psi)Go to Step 7–
5Observe the two pressure gauges.
Are both pressures below the value specified?69 kPa
(10 psi)Go to Step 6Go to Step 7
61. Add 0.45 kg (1 pound) of refrigerant R–134a.
2. Check the A/C system for leaks.
3. Repair any refrigerant leaks, as needed.
4. Recover, evacuate, and recharge the A/C sys-
tem.
5. Observe the two pressure gauges.
Are both pressures above the value specified?345 kPa
(50 psi)Go to Step 7–
71. Start the engine and allow it to run at idle.
2. Set the A/C controls to the following positions:
S The A/C switch to the ON.
S The fresh air control switch to fresh air (in-
dicator lamp OFF).
S The blower motor to 4.
S The temperature to full cold.
Does the A/C compressor clutch engage?–Go to Step 8Go to Step 10

7B – 14IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
151. Record the low– and the high–side pressures
after the A/C system has been operating for 5
minutes or more with the engine cooling fan
ON.
2. Locate the intersection of the low– and the high
side pressures. Refer to ”Low– and High–Side
Pressure Relationship Chart” in this section.
Do the low– and the high–side pressures intersect
in the white area of the chart?–System OKGo to Step 16
16Check the high– and the low–side pressures.
Do the low– and the high–side pressures intersect
in the grey area of the chart?–Go to Step 17Go to Step 20
17Feel the liquid pipe between the condenser and the
expansion valve.
Is the pipe cold?–Go to Step 18Go to Step 19
181. Examine the condenser for any restriction of
the airflow.
2. Check the cooling fans for proper operation.
3. Remove the restriction or repair the fans, as
required.
Is the pipe temperature normal now?At least 7°C
(12°F) below
ambient air
temperatureGo to Step 13–
191. Recover, evacuate, and recharge the A/C sys-
tem.
2. Check the A/C system for leaks.
Is the system free from leaks?–Go to Step 13–
20Observe the readings on the pressure gauges.
Are the A/C compressor high– and the low–side
pressures within the specified value of each other?207 kPa
(30 psi)Go to Step 21Go to Step 26
211. Run the engine at 3,000 rpm.
2. Set the A/C controls to the following positions:
S The A/C switch to the ON.
S The fresh air control switch to fresh air.
S The blower motor to 4.
S The temperature to full cold.
3. Close all of the vehicle’s windows and doors.
4. Turn the A/C switch ON and OFF every 20
seconds for 3 minutes.
Are the A/C compressor high– and the low–side
pressures within the specified value of each other?207 kPa
(30 psi)Go to Step 22Go to Step 13
22Observe the pressure rise on both gauges and the
temperatures of both the compressor suction pipe
and the discharge pipe.
Is the pressure rise on both gauges slow and the
suction pipe warm with the discharge pipe very hot?–Go to Step 25Go to Step 23
231. Turn the ignition switch to LOCK.
2. Make sure the compressor clutch is disen-
gaged.
3. Attempt to turn the clutch driver (not the
pulley).
Can you turn the clutch driver freely by hand?–Go to Step 25Go to Step 24

MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 15
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
241. Start the engine.
2. Observe the low–side pressure gauge while
running the engine between 3,000 and 3,800
rpm.
Does the low–side pressure rise rapidly?–Go to Step 32Go to Step 25
251. Recover the A/C system refrigerant.
2. Replace the A/C compressor.
3. Evacuate and recharge the A/C system.
Is the compressor functioning normally?–Go to Step 13–
26Check the low–side pressure.
Is the low–side pressure within the specified value?172–241 kPa
(25–35 psi)Go to Step 27Go to Step 32
27Feel the high–side pipe leading up to the expansion
valve connecting block.
Is the pipe cold before the connecting block?–Go to Step 28Go to Step 29
281. Check for a restriction in the high–side pipe
before the expansion valve.
2. Repair or replace the high–side pipe.
Is the pipe performing normally?–Go to Step 13–
29Add the specified amount of refrigerant to the A/C
system.
Does the cooling performance improve?0.40 kg
(14 ounces)Go to Step 30Go to Step 31
301. Check the A/C system for leaks.
2. Repair any refrigerant leaks, as needed.
3. Evacuate and recharge the A/C system.
4. Check the A/C system for leaks.
Is the system free from leaks?–Go to Step 13–
311. Recover the refrigerant.
2. Check the expansion valve for obstructions.
3. Repair or replace the expansion valve, as re-
quired.
4. Evacuate and recharge the system.
5. Check the A/C system for leaks.
Is the system free from leaks?–Go to Step 13–
321. Run the engine for 5 minutes at 2,000 rpm.
2. Set the A/C controls to the following positions:
S The A/C switch to the ON position.
S The fresh air control switch to recirculate
(indicator lamp ON).
S The blower motor to 1.
S The temperature to full cold.
3. Close all of the vehicle’s windows and doors.
4. Open the vehicle hood.
Is the low–side pressure within the specified value?172–241 kPa
(25–35 psi)Go to Step 13Go to Step 33
331. Recover the A/C system refrigerant.
2. Replace the A/C compressor control valve.
3. Evacuate and recharge the A/C system.
4. Check the A/C system for leaks.
Is the system free from leaks?–Go to Step 13–

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.