6C – 4IPOWER STEERING GEAR
DAEWOO V–121 BL4
Steering Surges or Jerks When Turning with Engine Running
ChecksAction
Check the power steering pump for insufficient pressure.Replace the power steering pump.
Check the power steering pump flow control valve for
sticking and improper operation.Replace the power steering pump.
Check the power steering pump serpentine belt for slip-
page.Tighten the power steering serpentine belt.
Check for air contamination in the power steering system.Bleed the power steering system.
Steering Vibrates During Low Speed or Static Steering
ChecksAction
Check for air contamination in the power steering system.Bleed the power steering system.
Check the power steering pump serpentine belt for loose-
ness.Tighten the power steering serpentine belt.
Excessive Wheel Kickback or Loose Steering
ChecksAction
Check for air contamination in the power steering system.Bleed the power steering system.
Check the wheel bearings for wear or damage.Replace the wheel bearings.
Check the steering gear mounting for improper installa-
tion.Tighten the steering gear mounting bracket nuts and bolts.
Check the intermediate shaft joints for improper installa-
tion.Adjust the intermediate shaft between the steering gear
and the steering column.
Replace the intermediate shaft.
Check the outer tie rods and ball joints for looseness.Tighten the tie rods and the ball joints. Replace the tie rods
and the ball joints.
Hard Steering or Lack of Assist (Especially During Parking)
ChecksAction
Adjust the intermediate shaft between the steering gear
and the steering column. Replace the coupling flange.Adjust the steering coupling flange on the steering gear
and the steering column. Replace the coupling flange as
needed.
Check the power steering pump flow control valve for
sticking and improper installation.Replace the power steering pump.
Check the power steering pump for insufficient pressure.Replace the power steering pump.
Check the power steering pump for internal leaks.Replace the power steering pump.
Check for a loose or a worn intermediate shaft.Tighten the intermediate shaft. Replace the intermediate
shaft as needed.
Check the power steering pump serpentine belt tension.Tighten the power steering serpentine belt.
7A – 6IHEATING AND VENTILATION SYSTEM
DAEWOO V–121 BL4
DIAGNOSIS
HEATER SYSTEM
INSUFFICIENT HEATING OR DEFROSTING
CAUTION : The cooling system is pressurized when hot. Injury can result from removing the surge tank cap be-
fore the engine is sufficiently cool.
Step
ActionValue(s)YesNo
1Verify the customer’s complaint.
Are the customer’s concerns verified?–Go to Step 2System OK
2Check the coolant level.
Is the coolant level correct?–Go to Step 4Go to Step 3
3Add coolant as needed.
Is the repair complete?–System OKGo to Step 4
4Check the timing belt for tension or damage.
Are the drive belts OK?–Go to Step 6Go to Step 5
5Correct any problem with the timing belt.
Is the repair complete?–System OKGo to Step 6
6Check the coolant hoses for leaks or kinks.
Are the coolant hoses OK?–Go to Step 8Go to Step 7
7Repair any problem with the coolant hoses.
Is the repair complete?–System OKGo to Step 8
8Check the surge tank cap. Refer to Section 2D, En-
gine Cooling.
Is the surge tank cap OK?–Go to Step 10Go to Step 9
9Repair or replace the surge tank cap as needed.
Is the repair complete?–System OKGo to Step 10
101. Turn the A/C switch OFF on vehicles equipped
with air conditioning (A/C).
2. Set the blower motor switch on maximum
speed.
3. Set the heater control to full hot.
4. Turn the ignition ON.
5. Check for airflow from the vent outlet.
Is there heavy airflow from the heater outlet?–Go to Step 11Go to Step 26
11Check for a change in the airflow at various blower
speeds.
Does the blower speed increase as the switch is
turned from 1 to 4.–Go to Step 12Go to ”Blower
Electrical
(Manual and
Non–A/C)”
121. Turn the A/C switch OFF.
2. Set the temperature lever to full hot.
3. Set the blower motor switch on maximum
speed.
4. With the engine sufficiently cool, remove the
surge tank cap.
5. Start the vehicle and idle the engine.
6. Watch for the flow of the coolant.
Is the coolant flow visible?–Go to Step 14Go to Step 13
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 – 34IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
COMPRESSOR
Removal Procedure
1. Disconnect the negative battery cable.
2. Discharge and recover the refrigerant. Refer to
”Discharging, Adding Oil, Evacuating, and Charging
Procedures for A/C System” in this section.
3. Remove the discharge hose mounting nut.
4. Lift the discharge hose mounting block and the suc-
tion hose from the compressor.
5. Raise and suitably support the vehicle.
6. Remove the engine under cover. Refer to Section
9N, Frame and Underbody.
7. Remove the accessory drive belt.
8. Disconnect the electrical connector at the compres-
sor.
9. Remove the compressor–to–bracket bolts. (1.4
DOHC shown, others similar)
10. Remove the compressor.
11. Drain the oil from the compressor into a container.
Measure the amount of the oil that is drained. Then
discard the used oil.
Installation Procedure
1. Add oil to the new compressor. Use the exact
amount of oil that you drained from the old com-
pressor.
2. Install the compressor.
3. Install the compressor–to–bracket mounting bolts.
Tighten
(1.4 DOHC, 1.6 DOHC only)
Tighten the upper compressor–to–bracket mounting
bolts(M8) to 25 NSm (18 lb–ft).
Tighten the lower compressor–to–bracket mounting
bolts(M10) to 45 NSm (33 lb–ft).
MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 35
DAEWOO V–121 BL4
Tighten
(1.8 DOHC, 2.0 DOHC only)
Tighten the front compressor–to–bracket mounting
bolts to 35 NSm (26 lb–ft).
Tighten the rear compressor–to–bracket mounting
bolts to 20 NSm (15 lb–ft).
4. Install new sealing washers to the suction hose and
the discharge hose mounting.
5. Connect the electrical connector at the compressor.
6. Install the accessory drive belt.
7. Install the engine under cover. Refer to Section 9N,
Frame and Underbody.
8. Lower the vehicle.
9. Place the suction hose into its cavity in the com-
pressor and install the discharge hose mounting
block to clamp it into place. Hold this all together
while tightening the retaining nut.
Tighten
Tighten the refrigerant discharge hose block–to–
compressor retaining nut to 33 NSm (24 lb–ft).
10. Connect the negative battery cable.
11. Evacuate and recharge the A/C system. Refer to
”Discharging, Adding Oil, Evacuating, and Charging
Procedures for A/C System” in this section.
CONDENSER
Removal Procedure
1. Disconnect the negative battery cable.
2. Discharge and recover the refrigerant. Refer to
”Discharging, Adding Oil, Evacuating, and Charging
Procedures for A/C System”in this section.
3. Remove the front bumper. Refer to Section 9O,
Bumpers and Fascias.
4. Remove the discharge hose block–to–condenser
retaining nut.
5. Remove the discharge hose from the condenser.
6. Remove the liquid pipe block–to–receiver–dryer
cretaining nut.
7. Remove the liquid pipe from the receiver–dryer.
7B – 46IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
5. Use the snap ring pliers J–5403 to install the shaft
seal retaining ring with its flat side against the seal.
6. Remove any excess oil around the shaft and the
inside of the compressor housing neck.
7. Install the clutch plate and hub assembly. Refer to
”Clutch Plate and Hub Assembly” in this section.
8. Reposition the compressor in its mounting.
9. Adjust the tension on the serpentine accessory
drive belt.
10. Connect the negative battery cable.
11. Evacuate and recharge the A/C system. Refer to
”Discharging, Adding Oil, Evacuating, and Charging
Procedures for A/C System” in this section.
12. Perform a leak test of the system. Refer to ”Leak
Testing the Refrigerant System” in this section.
CONTROL VALVE ASSEMBLY
Tools Required
J–5403 Snap Ring Pliers
Removal Procedure
1. Recover the refrigerant. Refer to ”Discharging,
Adding Oil, Evacuating, and Charging Procedures
for A/C System” in this section.
2. Remove the control valve retaining ring using the
snap ring pliers J–5403.
3. Remove the control valve assembly.
Installation Procedure
1. Coat all the O–rings with clean polyalkaline glycol
(PAG) oil.
2. Push the control valve in place using thumb pres-
sure.
3. Use the snap ring pliers J–5403 to install the valve
retaining ring. The high point of the curved sides
must be against the valve housing. Be sure the re-
taining ring is properly seated in the ring groove.
4. Evacuate and recharge the A/C system. Refer to
”Discharging, Adding Oil, Evacuating, and Charging
Procedures for A/C System” in this section.
MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 51
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
GENERAL INFORMATION
THE V5 A/C SYSTEM
The V5 variable displacement compressor along with the
thermal expansion valve on the evaporator, constitutes a
largely self–regulating system. There is no pressure cycl-
ing switch, no high–pressure cut–off switch and no low–
pressure cut–off switch. The compressor clutch is con-
trolled by the electronic control module (ECM), which
receives data from various engine systems and from a
pressure transducer located in the high–pressure refriger-
ant pipe. In normal operation, the clutch is engaged contin-
uously. Should one of the monitored conditions become
abnormal, the ECM will disengage the compressor clutch
until normal operation is restored. These conditions in-
clude the following:
S Wide–open throttle.
S High engine coolant temperature.
S High engine RPM.
S Refrigerant low pressure.
S Refrigerant high pressure.
The compressor clutch will remain disengaged until nor-
mal operation is established.
SYSTEM
COMPONENTS–FUNCTIONAL
Compressor
All compressors are belt–driven from the engine crank-
shaft through the compressor clutch pulley. The compres-
sor pulley rotates without driving the compressor shaft un-
til an electromagnetic clutch coil is energized. When
voltage is applied to energize the clutch coil, the clutch
plate and hub assembly is drawn rearward toward the
pulley. The magnetic force locks the clutch plate and
pulley together as one unit to drive the compressor shaft.
As the compressor shaft is driven, it compresses the low–
pressure refrigerant vapor from the evaporator into a
high–pressure, high–temperature vapor. The refrigerant
oil which is used to lubricate the compressor is carried with
the refrigerant. Refer to ”V5 Air Conditioning Compressor
Overhaul” in this section.
Condenser Core
The condenser assembly in front of the radiator consists
of coils which carry the refrigerant, and cooling fins that
provide the rapid transfer of heat. The air passing through
the condenser cools the high–pressure refrigerant vapor
and causes it to condense into a liquid.
Expansion Valve
The expansion valve is located with the evaporator core,
on the front passenger side fire wall.
The expansion valve can fail in three different positions:
open, closed, or restricted.
An expansion valve that fails in the open position will result
in a noisy A/C compressor or no cooling. The cause can
be a broken spring, a broken ball, or excessive moisture
in the A/C system. If the spring or the ball are found to be
defective, replace the expansion valve. If excessive mois-
ture is found in the A/C system, recycle the refrigerant.
An expansion valve that fails in the closed position will re-
sult in low suction pressure and no cooling. This may be
caused by a failed power dome or excessive moisture in
the A/C system. If the power dome on the expansion valve
is found to be defective, replace the expansion valve. If ex-
cessive moisture is found in the A/C system, recycle the
refrigerant.
A restricted expansion valve will result in low suction pres-
sure and no cooling. This may be caused by debris in the
refrigerant system. If debris is believed to be the cause, re-
cycle the refrigerant, replace the expansion valve, and re-
place the receiver–dryer.
Evaporator Core
The evaporator is a device which cools and dehumidifies
the air before it enters the vehicle. High–pressure liquid re-
frigerant flows through the expansion tube orifice and be-
comes a low–pressure gas in the evaporator. The heat in
the air passing through the evaporator core is transferred
to the cooler surface of the core, which cools the air. As the
process of heat transfer from the air to the evaporator core
surface is taking place, any moisture or humidity in the air
condenses on the outside surface of the evaporator core
and is drained off as water.
Receiver–Dryer
The sealed receiver–dryer assembly is connected to the
condenser outlet pipe. It acts as a refrigerant storing con-
tainer, receiving liquid, vapor, and refrigerant oil from the
evaporator.
At the bottom of the receiver–dryer is the desiccant, which
acts as a drying agent for the moisture that may have en-
tered the system. An oil bleed hole is located near the bot-
tom of the receiver–dryer outlet pipe to provide an oil re-
turn path to the compressor. The receiver–dryer is
serviceable only as an assembly.
Heater Core
The heater core heats the air before it enters the vehicle.
Engine coolant is circulated through the core to heat the
outside air passing over the fins of the core. The core is
functional at all times and may be used to temper condi-
tioned air in the A/C mode as well as in the heat or the vent
modes.