Heating and Air Conditioning: Service Precautions

Safety Measures

The subassemblies and lines of the air conditioner are filled with Tetrafluoroethane also known as refrigerant R-134a.

A label on the lock carrier in the engine compartment indicates the refrigerant type and capacity.


WARNING!
- Always use an Underwriter's Laboratory (UL) approved refrigerant recovery/recycling/recharging unit such as Kent Moore ACR4, or equivalent, whenever discharging an R-134a A/C system
- As of January, 1992 any person who services a motor vehicle air conditioner MUST, by law, be properly trained and certified and use approved refrigerant recycling equipment. Technicians must complete an EPA approved recycling course to be certified
- State and Provincial governments may have additional requirements regarding air conditioning servicing. Always comply with local laws
- A/C system is filled with refrigerant gas which is under pressure
- Always be careful that refrigerant does not come in contact with your skin
- If liquid refrigerant has come in contact with your skin or eyes:
- Do not rub skin or eyes
- Immediately flush with cool water for 15 minutes
- Rush to a doctor or hospital
- Do not attempt to treat yourself
- Work in a well air ventilated area because refrigerant gases are heavier than air, displace oxygen and may cause suffocation in areas of poor air circulation, like under the car
- Avoid breathing refrigerant vapors. Exposure may irritate eyes, nose and throat
- Always wear hand and eye protection (gloves and goggles) when working around the A/C system
- Keep refrigerant containers stored below 50 °C (122 °F) and never drop from high places. DO NOT warm refrigerant containers with an open flame. If refrigerant needs to be warmed, place bottom of tank in warm water.
- Keep refrigerant away from open flames because poisonous gas will be produced if it burns. Do not smoke when refrigerant gases are present for the same reason
- Electric welding near refrigerant hoses causes R-134a to decompose from ultraviolet light. Discharge system before electric welding
- Pressurized R-134a refrigerant in the presence of oxygen may form a combustible mixture. Never introduce compressed air into any R-134a container (full or empty), A/C component or piece of service equipment
- Do not expose any component of the A/C system to high temperatures (for example, open flames). Excessive heat will cause a pressure increase which could burst the system
- Do not steam clean condensers or evaporators. Use only cold water or compressed air


CAUTION!
- Before working on electrical system, obtain radio security code and disconnect battery Ground (GND) strap
- After reconnecting battery:
1) Always reactivate and check operation of vehicle equipment such as radio, clock, and power windows according to Repair Manual and/or Owner's Manual
2) Activate Readiness Code See Repair Manual, OBD II Fuel Injection & Ignition.
- R-12 and R-134a refrigerant are NOT compatible. Never add R-12 refrigerant to an R-134a system or R-134a refrigerant to an R12 system. If the refrigerants are mixed, total system contamination will occur and compressor failure may result
- Refrigerant oils used for the R-134a system and R-12 system are NOT compatible. Use only the specified synthetic oil (Poly alkylene Glycol/PAG) for the R-134a refrigerant system. DO NOT use R-12 system oil in an R-134a system or R-134a system oil in an R-12 system. If the refrigerant oils are mixed, system contamination will occur and compressor failure may result
- R-134a refrigerant system oil (PAG oil) absorbs moisture very rapidly. Moisture combines with the refrigerant to form acids which will damage the system. Use only the specified oil from a sealed container and ALWAYS reseal oil container immediately after use. DO NOT use oil if it has become contaminated with moisture
- Immediately plug open connections on A/C components to prevent dirt and moisture contamination. Likewise, DO NOT remove new components from packaging until ready to install. Immediately tighten component connections after installation
- Always use separate refrigerant recovery/recycling/recharging servicing equipment for R-12 and R-134a systems. DO NOT use one piece of equipment for both R12 and R-134a systems. The residual traces of refrigerant will contaminate and damage the equipment. Servicing equipment includes recovery/recycling/recharging unit, charging station, vacuum pump, manifold gauges, etc.
- DO NOT use R-12 servicing equipment on R-134a systems or R-134a equipment on R-12 Systems or damage to both the vehicle A/C system and servicing equipment may result. Use only equipment designed to meet Society of Automotive Engineers (SAE) standards
- R-134a and R-12 systems use different size service fittings. NEVER use adaptors to convert an R-12 fitting to R-134a size or R-134a fitting to R-12 size
- R-134a and R-12 A/C components including compressor, hoses, O-rings, evaporator, condenser, receiver-drier, etc. are NOT interchangeable. Components of the R-134a system are identified by lettering (R-134a) or by a green label (or stripe). In addition a label on the upper radiator support identifies which type refrigerant is used. Use only the correct system component for each refrigerant type
- Always replace damaged and/or leaking A/C system components. Do not attempt repair by soldering or welding
- Work area must be extremely clean when working on A/C system components discharge A/C system before removing any A/C system component
- Always reinstall caps over A/C service valves
- Always replace O-rings, DO NOT reuse. Use only the correct size and type of O-rings specified for use with R-134a refrigerant. Lubricate O-ring with refrigerant oil before installing