Electronic Leak Detector
TOOLS REQUIREDJ 39400-A Electronic Leak Detector
IMPORTANT: Electronic leak detectors are sensitive to the following liquids:
^ Windshield washing solutions
^ Solvents
^ Cleaners
^ Adhesives
Ensure that the surfaces are clean in order to prevent a false warning. Ensure that the surfaces are dry as ingestion of liquids will damage the detector.
J 39400-A is useful for locating refrigerant leaks. The J 39400-A operates on a 12 volt DC and emits signal that increases in frequency as R-134a is detected. Calibrate the instrument according to the included instructions. Ensure that the detector is used in the proper setting for the type of refrigerant that you are testing. Place the GAS switch in the R-134a setting before you begin the test.
Most leaks are found at the refrigerant fittings and connections. These leaks can be caused by the following conditions:
^ Improper torque
^ Damaged O-Rings
^ Lack of lubricant on the O-ring seals
^ Dirt or debris on the O-ring seals.
^ Lint from cotton gloves or shop cloths
IMPORTANT: Follow the refrigerant system around a continuous path so that no potential leaks are missed. Test all areas of the system in order to ensure the entire system is leak free, even if you have already found a leak.
Observe the scan rate and follow the manufacturer's instructions when using the electronic leak detector. Encircle each joint with the tip of the probe moving at 25-51 mm (1-2 in) per second. Ensure that the tip of the probe is no more than 6 mm (0.25 in) away from the surface without blocking the air intake. An audible tone that goes from 1-2 clicks per second to a solid alarm indicates a leak. Adjust the balance arm frequently in order to maintain the clicks.
Use this procedure in order to test the following components:
^ The evaporator inlet and outlet
^ The accumulator inlet and outlet
^ All of the brazed and welded areas
^ Areas that show signs of damage
^ Hose couplings
^ The compressor rear head
^ Housing joints