Leak Testing The Refrigerant System; Liquid Leak Detectors; Electronic Leak Detectors; Testing The Evaporator Core - Daewoo Nubira Owner's Manual

7B – 12IMANUAL CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM
LEAK TESTING THEREFRIGERANT
SYSTEM
Test for leaks whenever a refrigerant leak in the system is
suspected. Also, test for leaks whenever a service opera-
tion which results in disturbing the lines or the connections
is performed. Leaks are commonly found at the refrigerant
fittings or at the connections. Leaks are commonly caused
by the following problems:
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Improper torque.
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Damaged O–ring seals.
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Dirt or lint on the O–ring seals.

Liquid Leak Detectors

Use a liquid leak detector solution on locations such as the
fittings. Apply the solution to the area in question with the
swab that is supplied with the solution. Look for bubbles
to appear. This will indicate the existence and location of
any leak.
For areas where this is not practical, such as sections of
the evaporator and the condenser, an electronic leak de-
tector is more useful.

Electronic Leak Detectors

Follow the manufacturer's instructions for calibration, op-
eration, and maintenance of an electronic leak detector.
Battery condition is especially important to the accuracy
of a portable model. Set the detector to R–134a before be-
ginning the test.
Important : Electronic leak detectors are sensitive to
windshield washing solutions, solvents and cleaners, and
certain vehicle adhesives.
Surfaces must be clean to prevent false readings. Make
sure that all surfaces are dry to prevent damage to the de-
tector.
General Testing Instructions
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Follow the entire path of the refrigerant system.
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Completely circle each joint at 25 to 50 mm (1 to 2
inches) per second.
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Hold the probe tip within 6 mm (1/4 inch) of the sur-
face.
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Do not block the air intake.
The audible tone changes from 1 to 2 clicks per second
into a solid alarm if there is a leak. Adjust the balance con-
trol to maintain 1 to 2 clicks per second.
Test all of the following areas, even after one leak has been
confirmed:
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Evaporator inlet and outlet.
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Receiver–drier inlet and outlet.
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Condenser inlet and outlet.
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Brazed and welded areas.
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Damaged areas.
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Hose couplings.
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Compressor rear head.
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All fittings and joints.
Testing Service Ports/Access Valves
The sealing caps provide protection for the service ports.
Make sure that these caps are not missing or loose. Al-
ways use the correct cap for each port.

Testing the Evaporator Core

Leaks in the evaporator core are difficult to find. Test the
evaporator core using the following procedure:
1. Run the blower fan at speed setting 4 for at least 15
minutes.
2. Turn the blower OFF.
3. Wait for 10 minutes.
4. Remove the blower motor resistor. Refer to"Blower
Resistor" in this section.
5. Insert the leak detector probe as close as possible
to the evaporator core. The detector will indicate a
leak with a solid alarm.
6. Use a flashlight to search for refrigerant oil in the
core surface.
Testing the Compressor Shaft Seal
1. Blow shop air behind and in front of the compressor
clutch/pulley for at least 15 seconds.
2. Wait 1 to 2 minutes.
3. Probe the area in front of the pulley. If the detector
emits a solid alarm, there is a leak.
DAEWOO V–121 BL4