CPS LS780B Manual De Usuario página 5

OPERATING INSTRUCTIONS
SAE J1628 RECOMMENDED PROCEDURE
NOTE: On automotive A/C systems, test with the engine
not in operation.
1.The air conditioning or refrigeration system should be
charged with sufficient refrigerant to have a gauge pressure
of at least 340kPa/50psi when not in operation. At
temperatures below 15°C/59°F, leaks may not be
measurable, since this pressure may not be reached.
2.Take care not to contaminate the detector probe tip if the
part being tested is contaminated. If the part is particularly
dirty, or condensate (moisture) is present it should be
wiped off with a dry shop towel or blown off with shop air.
No cleaners or solvents should be used, since the detector
may be sensitive to their ingredients.
3.Visually trace the entire refrigerant system and look for
signs of air conditioning lubricant leakage, damage, and
corrosion on all lines, hoses, and components. Each
questionable area should be carefully checked with the
detector probe, as well as all fittings, hose to line couplings,
refrigerant controls, service ports with caps in place, brazed
or welded areas, and areas around attachment points and
hold down on lines and components.
4.Always follow the refrigerant system around in a continuous
path so that no areas of potential leaks are missed. If a leak
is found, always continue to test the remainder of the
system.
5.At each area checked, the probe should be moved around
the location, at a rate no more than 25 to 50 mm/second
(1-2 in/second), and no more than 5 mm (1/4 in) from the
surface, completely around the position. Slower and closer
movement of the probe greatly improves the likelihood of
finding a leak.
6.An apparent leak shall be verified at least once by blowing
shop air into the area of the suspected leak, if necessary
and repeating the check of the area. In cases of very large
leaks, blowing out the area with shop air often helps locate
the exact position of the leak.
7.Leak testing of the evaporator core while in the air
conditioning module shall be accomplished by turning
the air conditioning blower on high for a period of 15
seconds minimum, shutting it off, then waiting for the
refrigerant to accumulate in the case for ten minutes. Next,
insert the leak detector probe into the blower resistor block
or condensate drain hole if no water is present, or into the
closest opening in the heating/ventilation/air conditioning
case to the evaporator, such as the heater duct or a vent
duct. If the detector alarms, a leak apparently has been
found.
8.Following any service to the refrigerant system, and any
other service which disturbs the refrigerant system, a leak
test of the repair and of the service ports of the refrigerant
system should be done.
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