Refrigerant: Testing and Inspection
Checking for Refrigerant LeaksPerform a visual inspection of all refrigeration parts, fittings, hoses and components for signs of A/C lubricant leakage, damage, and corrosion. Any A/C lubricant leakage may indicate an area of refrigerant leakage. Allow extra inspection time in these areas when using either an electronic refrigerant leak detector (J-41995) or fluorescent dye leak detector (J-42220).
If any dye is observed using a fluorescent dye leak detector (J-42220), confirm the leak using a electronic refrigerant leak detector (J-41995). It is possible that the dye is from a prior leak that was repaired and not properly cleaned.
When searching for leaks, do not stop when one leak is found but continue to check for additional leaks at all system components and connections. When searching for refrigerant leaks using an electronic refrigerant leak detector (J-41995), move the probe along the suspected leak area at 25 - 50 mm (1 - 2 in) per second and no further than 6 mm (1/4 in) from the component.
CAUTION: Moving the electronic refrigerant leak detector probe slower and closer to the suspected leak area will improve the chances of finding a leak.
Checking System for Leaks Using the Fluorescent Dye Leak Detector
1. Check the A/C system for leaks using the fluorescent dye leak detector and safety goggles (J-42220) in a low sunlight area (area without windows preferable). Illuminate all components, fittings and lines. The dye will appear as a bright green/yellow area at the point of leakage. Fluorescent dye observed at the evaporator drain opening indicates an evaporator core assembly leak (tubes, core or expansion valve).
2. If the suspected area is difficult to see, use an adjustable mirror or wipe the area with a clean shop rag or cloth, then inspect the shop rag or cloth with the fluorescent dye leak detector (J-42220) for dye residue.
3. After the leak is repaired, remove any residual dye using refrigerant dye cleaner (J-43872) to prevent future misdiagnosis.
4. Perform a system performance check and then verify the leak repair using a electronic refrigerant leak detector (J-41995).
NOTE:
- Other gases in the work area or substances on the A/C components, for example, anti-freeze, windshield washer fluid, solvents and lubricants, may falsely trigger the leak detector. Make sure the surfaces to be checked are clean.
- Clean with a dry cloth or blow off with shop air.
- Do not allow the sensor tip of the electronic refrigerant leak detector (J-41995) to contact with any substance. This can also cause false readings and may damage the detector.
Dye Injection
NOTE: This procedure is only necessary when recharging the system or when the compressor has seized and must be replaced.
1. Check the A/C system static (at rest) pressure. Pressure must be at least 345 kPa (3.52 kg-cm2, 50 psi).
2. Pour one bottle 7.4 cc (1/4 ounce) of the HFC-134a (R-134a) fluorescent leak detection dye (J-41447) into the HFC-134a (R-134a) dye injector (J-41459).
CAUTION: If repairing the A/C system or replacing a component, pour the HFC-134a (R-134a) fluorescent leak detection dye (J-41447) directly into the open system connection and proceed with the service procedures.
3. Connect the refrigerant dye injector (J-41459) to the low-pressure service valve.
4. Start the engine and switch the A/C system ON.
5. When the A/C system is operating (compressor running), inject one bottle 7.4 cc (1/4 ounce) of HFC-134a (R-134a) fluorescent leak detection dye (J-41447) through the low-pressure service valve using HFC-134a (R-134a) dye injector (J-41459). Refer to the manufacturer's operating instructions.
6. With the engine still running, disconnect the HFC-134a (R-134a) dye injector (J-41459) from the low-pressure service valve.
7. Operate the A/C system for a minimum of 20 minutes to mix the HFC-134a (R-134a) fluorescent leak detection dye (J-41447) with the A/C system oil. Depending on the leak size, operating conditions and location of the leak, it may take from minutes to days for the HFC-134a (R-134a) fluorescent leak detection dye to penetrate an A/C system leak and become visible.
Electronic Refrigerant Leak Detector
PRECAUTIONS FOR HANDLING LEAK DETECTOR
NOTE: When performing a refrigerant leak check, use a electronic refrigerant leak detector (J-41995) or equivalent. Ensure that the electronic refrigerant leak detector (J-41995) is calibrated and set properly according to the manufacturer's operating instructions.
The electronic refrigerant leak detector (J-41995) is a delicate device. To use the leak detector properly, read the manufacturer's operating instructions and perform any specified maintenance.
1. Position the probe approximately 5 mm (3/16 in) away from the point to be checked as shown.
2. When checking for leaks, circle each fitting completely with the probe as shown.
3. Move the probe along each component at a speed of approximately 25 - 50 mm (1 - 2 in)/second as shown.
CHECKING PROCEDURE
NOTE: To prevent inaccurate or false readings, make sure there is no refrigerant vapor, shop chemicals, or cigarette smoke in the vicinity of the vehicle. Perform the leak test in a calm area (low air/wind movement) so that the leaking refrigerant is not dispersed.
1. Turn the engine OFF.
2. Connect the manifold gauge set (J-39183-C) to the A/C service ports. Refer to "SETTING OF SERVICE TOOLS AND EQUIPMENT".
3. Check if the A/C refrigerant pressure is at least 345 kPa (3.52 kg/cm2, 50 psi) above a temperature of 16 °C (61 °F). If less than specification, recover/evacuate and recharge the system with the specified amount of refrigerant. Refer to "HFC-134a (R-134a) Service Procedure".
NOTE: At temperatures below 16 °C (61 °F), leaks may not be detected since the system may not reach 345 kPa (3.52 kg/cm2, 50 psi) pressure.
4. Perform the leak test from the high-pressure side (A/C compressor discharge "a" to evaporator inlet "f") to the low-pressure side (evaporator drain hose "g" to compressor shaft seal "k"). Refer to "Components". Clean the component to be checked and carefully move the electronic refrigerant leak detector probe completely around the following connections and components.
- Check the compressor shaft seal
- Check the high and low-pressure pipe and hose fittings, and relief valve
- Check the liquid tank
- Check the refrigerant pressure sensor
- Check all around the service valves. Ensure service valve caps are secured on the service valves (to prevent leaks).
NOTE: After removing manifold gauge set (J-39183-C) from the service valves, wipe any residue from the service valves to prevent any false readings by the electronic refrigerant leak detector (J-41995).
- Evaporator
With engine OFF, turn blower fan on "High" for at least 15 seconds to dissipate any refrigerant trace in the heater and cooling unit assembly. Wait a minimum of 10 minutes accumulation time (refer to the manufacturer's recommended procedure for actual wait time) before inserting the electronic refrigerant leak detector probe into the heater and cooling unit assembly drain hose.
NOTE: Keep the probe inserted for at least 10 seconds. Use caution not to contaminate the probe tip with water or dirt that may be in the drain hose.
5. If a leak is detected, verify at least once by blowing compressed air into the area of the suspected leak, then repeat the leak check.
6. Do not stop when one leak is found. Continue to check for additional leaks at all system components and connections.
7. If no leaks are found, perform steps 8 - 11.
8. Start the engine.
9. Set the heater A/C controls as follows:
NOTE: For the automatic system, turn OFF the automatic controls and set the heater A/C controls manually.
a. A/C switch to ON
b. Air flow to VENT mode
c. Intake position to RECIRCULATION mode
d. Temperature to MAX cold
e. Blower speed to HIGH
10. Run the engine at 1,500 rpm for at least 2 minutes.
11. Turn the engine OFF and perform the leak check again following steps 4 through 6.
Refrigerant leaks should be checked immediately after turning the engine OFF. Begin with the leak detector at the compressor. The pressure on the high pressure side will gradually drop after the refrigerant circulation stops and pressure on the low pressure side will gradually rise, as shown in the graph. Some leaks are more easily detected when the pressure is high.
12. Before connecting the recovery/recycling recharging equipment to the vehicle, check the recovery/recycling recharging equipment gauges. No refrigerant pressure should be displayed. If pressure is displayed, recover the refrigerant from the equipment lines and then check the refrigerant purity.
13. Confirm refrigerant purity in supply tank using recovery/recycling recharging equipment and refrigerant identifier equipment (J-41810-NI).
14. Confirm the refrigerant purity in the vehicle's A/C system using recovery/recycling recharging equipment and refrigerant identifier equipment (J-41810-NI).
15. Discharge the A/C system using recovery/recycling recharging equipment. Repair the leaking fitting or component as necessary.
16. Evacuate and recharge the A/C system and perform the leak test to confirm that there are no refrigerant leaks.
17. Conduct the Operational Check to ensure system works properly. Refer to "Operational Check".