Halogen Leak Detector

TOOLS REQUIRED
J 39400-A Kent-Moore Leak Detector

CAUTION: Do not operate the detector in a combustible atmosphere since its sensor operates at high temperatures or personal injury and/or damage to the equipment may result.

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 ingesting liquids damages the detector. Use this procedure in order to test the following components:
^ The low side sensors
^ The high side sensors
^ The transducers
^ The switches
^ The evaporator inlet and outlet
^ The accumulator dryer inlet and outlet
^ The condenser inlet and outlet
^ The other connections
^ All of the brazed and welded areas
^ All of the areas with apparent damage
^ The hose couplings
^ The compressor rear head
^ The housing joints
^ Follow the refrigerant system in a continuous path so that you do not miss any areas of potential leaks. Test every area listed above in order to assure that the entire system is leak-free, even after finding a leak.

The electronic detector type of leak detector is the most useful tool in locating refrigerant leaks. The J 39400-A is a small unit that operates on 12V DC. The J 39400-A provides an audible signal that increases in frequency as R-134a is detected. The detector has three settings:
^ R-12
^ R134a
^ Gross

The gross leak setting isolates very large leaks located by using one of the other 2 settings. Properly calibrate the instrument in accordance with the included instructions. Use the detector in the proper setting for the type of refrigerant being tested. Prior to beginning the test, make sure the refrigerant system has a sufficient charge by measuring the static pressure with a gauge set. Readings in the range of 413.7-689.5 kPa (60-100 psi) are acceptable for leak testing.

The most common leaks are found at the refrigerant fittings or connections. The following conditions may cause leaks:
^ Improper torque
^ Damaged O-ring seals
^ Lack of O-ring seal lubrication
^ Dirt and debris across the O-ring seals

The successful use of this or any other electronic leak detector depends greatly upon the scan rate. The successful use of the detector depends upon 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 changing 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.