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.
SECTION : 9J
WINDNOISE
TABLE OF CONTENTS
DIAGNOSIS9J–1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Windnoise Diagnosis 9J–1. . . . . . . . . . . . . . . . . . . . . . . .
MAINTENANCE AND REPAIR9J–2 . . . . . . . . . . . . . . . . ON–VEHICLE SERVICE 9J–2. . . . . . . . . . . . . . . . . . . . . .
Windnoise Repair 9J–2. . . . . . . . . . . . . . . . . . . . . . . . . . .
DIAGNOSIS
WINDNOISE DIAGNOSIS
CAUTION : An assistant should drive the vehicle
while the technician checks for the location of the
windnoise, in order to prevent personal injury or ve-
hicle damage.
A test drive in the vehicle is necessary to accurately deter-
mine the location of the windnoise. Often there is a primary
leak and secondary leaks. Failure to repair all leaks will
only reduce the windnoise, not eliminate it.
During the test drive the technician should bring the follow-
ing items to aid in determining the location of the wind-
noise.
S A mechanics stethoscope or vacuum hose
S Masking tape
S Strip caulk
S A china marking pencil
S A screwdriver
Perform the following steps in order to conduct the road
test:
1. Choose a route that includes smooth straight
streets that run in all four directions (north, south,
east, and west).
2. Choose streets with little traffic or noise that would
interfere with the test.
3. Drive the vehicle at the speeds at which the noise
was noticed by the customer or until the noise is
produced. Do not exceed legal speed limits.
4. The windnoise is external if any of the following
conditions occur:
S The windnoise is caused by the wind.S The windnoise can be heard with the door glass
lowered and while the vehicle is being driven.
S The windnoise is eliminated when tape is placed
over various moldings and gaps.
5. Internal windnoise is air leaving the vehicle and
should be repaired in the following manner.
S In order to locate the leak, tape off the body lock
pillar pressure relief valves. This will cause air
pressure to build up inside the vehicle and en-
hance the windnoise.
S Use a stethoscope or a vacuum hose to locate
the leak.
S Temporarily repair the leak with masking tape.
S Continue testing in order to determine if the
noise has been eliminated or if other leaks exist.
S When all leaks have been found, return to the
shop and make permanent repairs with the
proper alignment techniques and sealing materi-
als.
