Sae Refrigerant Leak Detection Tips - Greenlee HRCG-300 Instruction Manual

SAE Refrigerant Leak Detection Tips

The following was derived from SAE Surface Vehicle Standard J1628, Technician Procedure for Using
Electronic Refrigerant Leak Detectors for Service of Mobile Air-Conditioning Systems:
• The electronic leak detector shall be operated in accordance with the equipment manufacturer's
operating instructions.
• Leak test with the engine not in operation.
• The air-conditioning system shall be charged with sufficient refrigerant to have a gauge pressure of
at least 340 kPa (49 psi) when not in operation. At temperatures below 15 C (59 F), leaks may not
be measurable since this pressure may not be reached.
• Take care not to contaminate the detector probe tip if the part being tested is contaminated. If the
part is particularly dirty, it should be wiped off with a dry shop towel or blown off with shop air. No
cleaners or solvents shall be used since many electronic detectors are sensitive to their ingredients.
• 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 shall 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-downs on lines and components.
• 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.
• At each area checked, the probe shall be moved around the location, at a rate no more than 25 mm/s
to 50 mm/s (1 in/s to 2 in/s), and no more than 5 mm (0.2 in) from the surface completely around
the position. Slower and closer movement of the probe greatly improves the likelihood of finding a
leak.
• 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.
• 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 an additional 15 seconds minimum for the refrigerant to accumulate in the case, then
inserting 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 activates, a leak apparently has been found.
• Following any service to the refrigerant system of the vehicle, and any other service which disturbs
the refrigerant system, a leak test of the repair and of the service ports of the refrigerant system shall
be done.
HRCG-300
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