Heating and Air Conditioning: Service Precautions

The subassemblies and lines of the air conditioner (A/C) are filled with difluorodichloromethane (CF2,CI2,) or dichlorodifluoromethane (CCL2F2) as a refrigerant. These refrigerants are known under the commercial name of Frigen R-12 and Freon R-12.

WARNING!
- A/C system is filled with R- 12 refrigerant which is under pressure.
- Always be careful that R-12 refrigerant does not come in contact with your skin.
- Always wear hand and eye protection when working around the system.
- If liquid R-12 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
- Automotive refrigerant containing CFC's is hazardous to the earth's atmosphere. To protect our environment, use an Underwriter's Laboratory (UL) approved refrigerant recovery/recycling unit such as Kent-Moore ACR3, or equivalent, whenever discharging an A/C system.
- Work in a well ventilated area because R-12 refrigerant evaporates quickly and breathing may be difficult due to lack of oxygen.
- R-12 refrigerant is heavier than air and will gather first in low places, like under the car.
- Keep R-12 refrigerant containers stored below 50 °C (122 °F) and never drop from high places.
- Keep R-12 refrigerant away from open flames because poisonous gas will be produced if it burns. Do not smoke when R-12 refrigerant are present for the same reason.
- Electric welding near refrigerant hoses causes R-12 refrigerant to decompose from ultraviolet light. Discharge system before electric welding. Service and Repair
- 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.
- Effective January 1, 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 local governments may have additional requirements regarding air conditioning servicing. Always comply with state and local laws.

CAUTION:
- Always replace damaged and/or leaking A/C system components. Do not attempt repair by soldering or welding.
- Always plug open connections on A/C components to prevent dirt and moisture contamination.
- DO NOT leave A/C system open for a long period of time. Prolonged exposure to the air will contaminate the system and will require the replacement of the accumulator and possibly other system components.
- Work area must be extremely clean when working on A/C system components.
- Discharge A/C system before removing any A/C system component.
- Keep A/C refrigerant oil container sealed to prevent moisture contamination.
- Refrigerant system has no sight glass, system must not be topped off.
- Always reinstall cap over A/C service valves.
- Always replace O-rings, DO NOT reuse. Lubricate new O-rings with refrigerant oil before installing. Replace O-rings only with the correct size and type. Description and Operation
After recharging A/C system:
- Start engine with A/C compressor OFF
- After idle has stabilized, switch compressor ON
- Operate compressor at idle speed for a minimum of two minutes before increasing engine speed (RPM)