R-134a Refrigerant A/C System: Service Precautions

Observe the following service precautions carefully when servicing R-134a air conditioner systems:

Only use service equipment that is U.L.-listed and is certified to meet the requirements of SAE J2210 (1991) to remove R-134a from the air conditioner.

CAUTION:
Exposure to air conditioner refrigerant and lubricant vapor or mist can irritate eyes, nose, and throat. Avoid breathing air conditioner refrigerant and lubricant vapor or mist.

If accidental system discharging occurs, ventilate work area before resuming service. Additional health and safety information may be obtained from the refrigerant manufacturers.

Refrigerants and Oils

Refrigerants R-12 and R-134a are not compatible with each other; do not mix them. Mixing R-12 and R-134a together even in the smallest quantities can result in air conditioner system and service equipment failure.

The refrigerant oils are also not compatible. R-12 refrigerant oil is mineral based. R-134a refrigerant uses a Polyalkylene glycol (PAG) synthetic-based oil. Mixing refrigerant oils will cause compressor failure. Use only the recommended oil for the compressor. Refer to the appropriate year and model of service manual for the specific type of refrigerant oil.

R-134a refrigerant and oil both have high hygroscopic properties, meaning they attract and absorb moisture rapidly. Observe the following instructions carefully:
1. When replacing or disconnecting refrigerant lines, be sure to plug or cap the lines and ports immediately to keep moisture and dust out of the system.

2. Before recharging the system, add the same amount of refrigerant oil removed during the recovery procedure. Always use new oil from a sealed container. Do not put used oil back in the container or the A/C system.

3. Immediately after using the refrigerant oil. replace the cap on the container to avoid moisture absorption.

Service Equipment

R-134a service equipment or vehicle air conditioner systems should not be pressure-tested or leak-tested with compressed air.

WARNING!
Some mixtures of air and R-134a have been shown to be combustible at elevated pressures and can result in fire or explosion, causing injury or property damage. Never use compressed air to pressure-test R-134a service equipment or vehicle air conditioner systems.

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

Always use a recovery/recycling/charging system that is U.L.-listed and certified to meet the requirements of SAE J2210 (1991) when servicing R-134a air conditioner systems.

If a vacuum pump is used for evacuation in place of a recovery/recycling/charging system, the vacuum pump must be equipped with a check valve to prevent the pump oil from backflowing into the air conditioner system.

Only use manifold gauges and related parts that are specially designed for R-134a (pressure gauges, hoses, joints, fittings, etc.). Do not try to interchange parts from R-12 equipment.