Electronic Leak Detector
TOOLS REQUIREDJ 39400-A Electronic Leak Detector
This type of leak detector is the most useful tool in locating refrigerant leaks. The J 39400-A is a small unit that operates on 12 V DC. The J 39400-A provides an audible signal that increases in frequency as R-134a is detected. Make sure the instrument is properly calibrated in accordance with the included instructions. Use the detector in the proper setting for the type of refrigerant being tested. Place the detector GAS switch in the R-134a setting prior to use.
The most common leaks are found at the refrigerant fittings or connections. The causes of common leaks may be the following conditions:
- Improper torque
- Damaged O-ring seals
- Dirt and debris across the O-ring seals
Even the smallest piece of lint from cotton gloves or shop cloths can create a leak path across an O-ring seal.
IMPORTANT: The halogen leak detectors are sensitive to windshield washing solutions, many solvents and cleaners, and some adhesives used in the vehicle. Prevent a false warning by making sure the surfaces are clean. Also, the surfaces should be dry, because the ingestion of liquids damages the detector.
The successful use of this and any other electronic leak detector depends greatly upon the scan rate. The successful use of the detector depends upon the carefully following the manufacturer's instructions regarding calibration, operation and maintenance.
Circle each joint completely. Move the probe at 25-51 mm (1-2 in) per second. Move the tip of the probe as close to the surface as possible, but no more than 6 mm (0.25 in) away. Do not block the air intake. The audible tone going from a steady 1-2 clicks per second to an a solid alarm indicates a leak. Frequently adjust the balance knob in order to maintain the rate of 1-2 clicks per second.