GMC chervolet camaro 1999 Service Manual page 117

1-26 HVAC System - Manual
Leak Testing
A refrigerant leak test should be performed on the
system whenever a leak is suspected due to system
indication of low charge or after any service operation
which disturbs the components, lines, or connections.
Many methods and special tools are available for
this purpose; however, no matter which tool is used,
care and diligence are the biggest keys to success.
Electronic Leak Detection Method
Tools Required
J 39400-A Halogen Leak Detector
Use the electronic leak detector when inspecting for
refrigeration system leaks. This unit operates on
a 12 volt DC. The leak detector provides an audible
signal which increases in frequency when a refrigerant
leak is detected. Properly calibrate the tool. Use the
tool at the proper setting for the system that you
are testing. The electronic leak detector has the
following three settings:
• R-12
• R-134a
• Gross leaks
This setting isolates very large leaks that are
found at one of the other settings
The halogen leak detectors are sensitive to windshield
washing solution, many solvents and cleaners, and
some adhesives. Work on a clean and dry surface.
Complete the following actions when you test
the joints:
• Completely circle each joint.
• Move the tool 25 - 50 mm (1 - 2 inch) per second.
• Ensure that the tip of the probe is no more
than 6 mm (0.25 inch) from the surface.
You may use this detector in order to test the following
joints:
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1. Inspect the refrigerant pressure sensor.
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2. Inspect the service valves.
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3. Inspect the lines.
4. Inspect the evaporator inlet/outlet.
5. Inspect the accumulator dryer inlet/outlet
connections.
6. Inspect the compressor rear head.
7. Inspect the housing joints.
8. A leak is indicated when the audible tone goes
from a steady 1-2 clicks per second to a solid
alarm. Adjust the balance knob frequently in order
to maintain the 1-2 clicks per second.
If a leak is not found, proceed to the Refrigerant
Leak Diagnosis table:
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