7B – 2IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
SPECIFICATIONS
GENERAL SPECIFICATIONS
ApplicationUnitDescription
Compressor–V5
Receiver–Dryer–AL R/DRIER
RefrigerantType–R–134a System
Capacityg640±20 (RHD : 680±20)
Refrigerant Oil in A/C SystemType–Union Carbide 488 PAG OIL
Capacitycc (ml)220
Evaporator Capacity (Airflow rate 8.7 kg/min)Kcal/h6000±10%
FASTENER TIGHTENING SPECIFICATIONS
ApplicationNSmLb–FtLb–In
Pressure Transducer7–62
Expansion Valve Stud Bolts8–71
Liquid Pipe Support Clamp Bolts4–35
Liquid Pipe Block–to–Receiver Dryer Retaining Nut1410–
Liquid Pipe Block–to–Expansion Valve Retaining Nut1410–
Refrigerant Discharge Hose Block–to–Condenser Retaining Nut1612–
Refrigerant Discharge Hose Block–to–Compressor Retaining Nut3324–
Evaporator Core Cover Screws1.2–11
Heater Core Housing–to–Evaporator Housing Retaining Screws1.2–11
Suction Hose Block–to–Compressor Retaining Nut3324–
Suction Hose Support Clamp–to–Longitudinal Member Bolt8–71
Suction Hose Support Clamp–to–Engine Bracket Bolt (1.4D, 1.6D only)4–35
Suction Hose Support Clamp–to–Engine Bracket Bolt (1.8D, 2.0D only)1410–
Suction Hose Block–to–Expansion Valve Retaining Nut1410–
(Receiver Dryer) Band Clamp Bolt5–44
Receiver Dryer–to–Condenser Pipe Block Bolt5–44
Upper Compressor–to–Bracket Mounting Bolts (1.4D, 1.6D only)2518–
Lower Compressor–to–Bracket Mounting Bolts (1.4D, 1.6D only)4533–
Front Compressor–to–Bracket Mounting Bolts (1.8D, 2.0D only)3526–
Rear Compressor–to–Bracket Mounting Bolts (1.8D, 2.0D only)2015–
Condenser Mount Bolts4–35
(Compressor) Clutch Plate and Hub Assembly Retaining Nut1713–
(Compressor) Through Bolts10–89
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.
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).
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
MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 13
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
81. Check for a knocking noise from the A/C com-
pressor.
2. Cycle the A/C compressor ON and OFF in or-
der to verify the source of the noise.
Do you hear a loud knocking noise?–Go to Step 9Go to Step 13
91. Recover the A/C system refrigerant.
2. Replace the A/C compressor.
3. Evacuate and recharge the A/C system.
4. Check the A/C system for leaks.
Is the compressor running normally?–Go to Step 13–
101. Turn the ignition switch to LOCK.
2. Disconnect the A/C compressor clutch coil con-
nector.
3. Connect a jumper wire from ground to one A/C
compressor clutch coil terminal.
4. Connect a fused jumper wire from the positive
battery terminal to the other A/C compressor
clutch coil terminal.
Does the A/C clutch engage?–Go to Step 11Go to Step 12
11Repair the electrical circuit to the A/C compressor
clutch coil.
Does the A/C clutch engage?–Go to Step 8–
12Replace the A/C compressor clutch coil.
Does the A/C clutch engage?–Go to Step 8–
131. Close all of the vehicle’s windows and doors.
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 fresh air.
S The blower motor to 4.
S The temperature to full cold.
3. Start the engine and allow it to run at idle for 5
minutes.
4. Feel the evaporator inlet and outlet pipes.
Is there a noticeable difference in the temperature of
the evaporator inlet and outlet pipes?–Go to Step 15Go to Step 14
141. Turn the ignition switch to LOCK.
2. Recover the A/C system refrigerant.
3. Examine the high–pressure pipe for an ob-
struction.
4. Examine the expansion valve for an obstruction
or a malfunction.
5. Repair the obstruction or replace the expansion
valve as needed.
6. Evacuate and recharge the A/C system.
7. Check the A/C system for leaks.
8. Note the discharge air temperature with the
A/C ON.
Is the discharge temperature normal?At least 7°C
(12°F) below
ambient air
temperatureGo to Step 15Go to Step 13
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–
7B – 22IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
Successful Transfer Complete
1. Close the high–side valve on the unit’s control pan-
el. Both valves should be closed.
2. Start the vehicle and the A/C system.
3. Let the engine run until the readings on the high–
side gauge and the low–side gauge stabilize.
4. Compare the readings to the system specifications.
5. Check the evaporator outlet temperature to ensure
that the A/C system is operating within the system
specifications.
6. Keep the A/C running.
7. Close the high–side coupler valve.
8. Disconnect the high–side hose from the vehicle.
9. Open the high–side and low–side valves on the
control panel. The system will quickly draw in refrig-
erant from both hoses through the low–side hose.
10. Close the low–side coupler valve.
11. Disconnect the low–side hose from the vehicle.
Unsuccessful Transfer
Sometimes the total charge does not transfer into the A/C
system. There are two reasons why this may occur:
1. The pressure in the unit’s tank and the pressure in
the A/C system are roughly equal.
S This will cause the transfer to proceed too slow-
ly.
S Refer to the manufacturer’s instructions for the
charging station in use.
2. There was not enough refrigerant in the unit’s tank
to transfer the full charge.
S It is necessary to recover the partial charge of
refrigerant from the vehicle and then evacuate
the A/C system and charge it again.
S Refer to the manufacturer’s instructions for the
charging station in use.