Nissan Sentra Service Manual: Precautions for refrigerant system service

WORKING WITH HFC-134a (R-134a)

CAUTION:

• CFC-12 (R-12) refrigerant and HFC-134a (R-134a) refrigerant are not compatible. Compressor malfunction is likely to occur if the refrigerants are mixed, refer to “CONTAMINATED REFRIGERANT” below. To determine the purity of HFC-134a (R-134a) in the vehicle and recovery tank, use Refrigerant recovery/recycling recharging equipment and Refrigerant Identifier.

• Use only specified oil for the HFC-134a (R-134a) A/C system and HFC-134a (R-134a) components.

  Compressor malfunction is likely to occur if oil other than that specified is used.

• The specified HFC-134a (R-134a) oil rapidly absorbs moisture from the atmosphere. The following handling precautions must be observed:

• Cap (seal) the component immediately to minimize the entry of moisture from the atmosphere when removing refrigerant components from a vehicle.

• Do not remove the caps (unseal) until just before connecting the components when installing refrigerant components to a vehicle. Connect all refrigerant loop components as quickly as possible to minimize the entry of moisture into system.

• Use only the specified oil from a sealed container. Reseal containers of oil immediately. Oil becomes moisture saturated and should not be used without proper sealing.

• Do not allow oil to come in contact with styrene foam parts. Damage may result.

CONTAMINATED REFRIGERANT

Take appropriate steps shown below if a refrigerant other than pure HFC-134a (R-134a) is identified in a vehicle:

• Explain to the customer that environmental regulations prohibit the release of contaminated refrigerant into the atmosphere.
• Explain that recovery of the contaminated refrigerant could damage service equipment and refrigerant supply.
• Suggest the customer return the vehicle to the location of previous service where the contamination may have occurred.
• In case of repairing, recover the refrigerant using only dedicated equipment and containers. Do not recover contaminated refrigerant into the existing service equipment. Contact a local refrigerant product retailer for available service if the facility does not have dedicated recovery equipment. This refrigerant must be disposed of in accordance with all federal and local regulations. In addition, replacement of all refrigerant system components on the vehicle is recommended.
• The air conditioner warranty is void if the vehicle is within the warranty period. Please contact Nissan Customer Affairs for further assistance.

GENERAL REFRIGERANT PRECAUTION

WARNING:

• Do not breathe A/C refrigerant and oil vapor or mist. Exposure may irritate eyes, nose and throat.

  Remove HFC-134a (R-134a) from the A/C system, using certified service equipment meeting requirements of SAE J-2210 [HFC-134a (R-134a) recycling equipment] or J-2209 [HFC-134a (R-134a) recovery equipment]. Ventilate work area before resuming service if accidental system discharge occurs.

  Additional health and safety information may be obtained from refrigerant and oil manufacturers.

• Do not release refrigerant into the air. Use approved recovery/recycling recharging equipment to capture the refrigerant each time an air conditioning system is discharged.

• Always wear eye and hand protection (goggles and gloves) when working with any refrigerant or air conditioning system.

• Do not store or heat refrigerant containers above 52В°C (126В°F).

• Do not heat a refrigerant container with an open flame; Place the bottom of the container in a warm pail of water if container warming is required.

• Do not intentionally drop, puncture or incinerate refrigerant containers.

• Do not refrigerant away from open flames; poisonous gas is produced if refrigerant burns.

• Refrigerant displaces oxygen; therefore be certain to work in well ventilated areas to prevent suffocation.

• Do not pressure test or leakage test HFC-134a (R-134a) service equipment and/or vehicle air conditioning systems with compressed air during repair. Some mixtures of air and HFC-134a (R-134a) have been shown to be combustible at elevated pressures. These mixtures, if ignited, may cause injury or property damage. Additional health and safety information may be obtained from refrigerant manufacturers.

REFRIGERANT CONNECTION

A new type of refrigerant connection has been introduced to all refrigerant lines except the following locations:

• Expansion valve to evaporator
• Refrigerant pressure sensor to liquid tank

WARNING:

Check that all refrigerant is discharged into the recycling equipment and the pressure in the system is less than atmospheric pressure. Then gradually loosen the discharge side hose fitting and remove it.

CAUTION:

• Observe the following when replacing or cleaning refrigerant cycle components.

• Store it in the same way as it is when mounted on the vehicle when the compressor is removed. Failure to do so will cause oil to enter the low-pressure chamber.

• Always use a torque wrench and a back-up wrench when connecting tubes.

• Plug immediately all openings to prevent entry of dust and moisture after disconnecting tubes.

• Connect the pipes at the final stage of the operation when installing an air conditioner in the vehicle.

  Do not remove the seal caps of pipes and other components until just before required for connection.

• Allow components stored in cool areas to warm to working area temperature before removing seal caps. This prevents condensation from forming inside A/C components.

• Remove moisture thoroughly from the refrigeration system before charging the refrigerant.

• Always replace used O-rings.

• Apply oil to circle of the O-rings shown in illustration when connecting tube. Be careful not to apply oil to threaded portion.

• O-ring must be closely attached to the groove portion of tube.

• Be careful not to damage O-ring and tube when replacing the O-ring.

• Connect tube until a click can be heard. Then tighten the nut or bolt by hand. Check that the O-ring is installed to tube correctly.

• Perform leakage test and make sure that there is no leakage from connections after connecting line.

  Disconnect that line and replace the O-ring when the refrigerant leaking point is found. Then tighten connections of seal seat to the specified torque.

COMPRESSOR

CAUTION:

• Plug all openings to prevent moisture and foreign matter from entering.

• Store it in the same way as it is when mounted on the car when the compressor is removed.

• Follow “Maintenance of Oil Quantity in Compressor” exactly when replacing or repairing compressor.

  Refer to HA-25, "Description".

• Keep friction surfaces between clutch and pulley clean. Wipe it off by using a clean waste cloth moistened with thinner if the surface is contaminated with oil.

• Turn the compressor shaft by hand more than five turns in both directions after compressor service operation. This distributes oil equally inside the compressor. Let the engine idle and operate the compressor for one hour after the compressor is installed.

• Apply voltage to the new one and check for normal operation after replacing the compressor magnet clutch.

LEAK DETECTION DYE

CAUTION:

• The A/C system contains a fluorescent leak detection dye used for locating refrigerant leakages. An ultraviolet (UV) lamp is required to illuminate the dye when inspecting for leakages.

• Always wear fluorescence enhancing UV safety goggles to protect eyes and enhance the visibility of the fluorescent dye.

• The fluorescent dye leak detector is not a replacement for an electrical leak detector (SST: J-41995).

  The fluorescent dye leak detector should be used in conjunction with an electrical leak detector (SST: J-41995) to pin-point refrigerant leakages.

• Read and follow all manufacture’s operating instructions and precautions prior to performing the work for the purpose of safety and customer’s satisfaction.

• A compressor shaft seal should not necessarily be repaired because of dye seepage. The compressor shaft seal should only be repaired after confirming the leakage with an electrical leak detector (SST: J-41995).

• Always remove any remaining dye from the leakage area after repairs are completed to avoid a misdiagnosis during a future service.

• Do not allow dye to come into contact with painted body panels or interior components. Clean immediately with the approved dye cleaner if dye is spilled. Fluorescent dye left on a surface for an extended period of time cannot be removed.

• Do not spray the fluorescent dye cleaning agent on hot surfaces (engine exhaust manifold, etc.).

• Do not use more than one refrigerant dye bottle [1/4 ounce (7.4 cc)] per A/C system.

• Leak detection dyes for HFC-134a (R-134a) and CFC-12 (R-12) A/C systems are different. Do not use HFC-134a (R-134a) leak detection dye in CFC-12 (R-12) A/C system or CFC-12 (R-12) leak detection dye in HFC-134a (R-134a) A/C system, or A/C system damage may result.

• The fluorescent properties of the dye remains for three or more years unless a compressor malfunction occurs.

NOTE:

Identification

• Vehicles with factory installed fluorescent dye have a green label.
• Vehicles without factory installed fluorescent dye have a blue label.