Leak Tests
CHECKING FOR A/C LEAKSWARNING: GOOD VENTILATION IS NECESSARY IN THE AREA WHERE A/C LEAK TESTING IS TO BE PERFORMED. IF THE SURROUNDING AIR IS CONTAMINATED WITH REFRIGERANT GAS, THE LEAK DETECTOR WILL INDICATE THIS GAS ALL THE TIME. ODORS FROM OTHER CHEMICALS SUCH AS ANTIFREEZE, DIESEL FUEL, DISC BRAKE CLEANER, OR OTHER CLEANING SOLVENTS CAN CAUSE THE SAME PROBLEM. A FAN, EVEN IN A WELL VENTILATED AREA, IS VERY HELPFUL IN REMOVING SMALL TRACES OF CONTAMINATION FROM THE AIR THAT MIGHT AFFECT THE LEAK DETECTOR.
LEAK DETECTOR, ELECTRONIC
1. Attach R-134a Manifold Gauge Set 176-R032A or equivalent to the service gauge port valves as indicated in the instruction manual provided in the A/C service kit.
2. Leave both manifold gauge set valves closed. Both gauges should indicate approximately 413-551 kPa (60-80 psi) at 24°C (75°F) with the engine off.
3. If very little or no pressure is indicated, charge the refrigerant system. Refer to the Charging System procedures. Evacuation and Charging
4. Leak test the refrigerant system using Rotunda R-134a Automatic Calibration Halogen Leak Detector 023-R1000 or equivalent.
The electronic leak detector will automatically calibrate itself when switched to the ON position. Move the leak detector probe slowly, approximately 25 mm (1 inch) per second, past the suspected area. When escaping refrigerant gas is detected, a ticking or beeping signal will be heard. As the amount of refrigerant gas detected increases, the rate of the ticking or beeping increases. If the refrigerant gas is relatively concentrated, the signal will become increasingly shrill. Follow the instructions included with the leak detector for proper handling and operating techniques.
5. If a leak is found in the refrigerant system, recover the refrigerant and service the system. Discharging and Recovery
LEAK TRACER DYE
Ford Motor Company now produces new cars with R-134a Leak Tracer Dye incorporated into the A/C system.
Vehicles produced with the dye will have a 3/4 inch yellow dot on top of the Suction Accumulator/Drier. Leak checking can be performed with the use of the Rotunda 120 Watt UV Spot Lamp 164-R0721 or equivalent. When checking for leaks, scan all components, fittings and lines of the A/C system with the UV lamp. The exact location of the leak or leaks can be pinpointed by the bright yellow-green glow of the tracer dye. Since more than one leak may exist in the system, always inspect each component.
1. When a spring lock fitting is suspected of a leak, always wipe the fitting clean and verify the leak with an electronic leak detector or R134a Leak Tracer Dye.
To achieve accurate results, always follow the manufacturer's instructions included with the electronic leak detector or tracer dye.
The best leak detection results will be achieved in conditions of low ambient light. In areas that cannot be reached by the UV lamp:
- use a mechanics mirror.
- use a non-fluorescent shop towel, wipe the suspected leak area and then check the towel with the UV lamp for a trace of the leak dye.
NOTE: The presence of oil at A/C spring lock couplings does not always indicate a refrigerant leak. Assembly plant processes apply oil to spring lock coupling fittings prior to connection to aid in assembly.
2. After the leak is repaired, traces of leak dye can be removed from the previously leaking areas by using any general purpose oil solvent.
3. Verify the repair by operating the A/C system for a short period of time and reinspecting with the UV lamp.