Refrigerant Cross Contamination

The 1994MY Legacy, Impreza and SVX models are equipped with the new 134a systems. However, the Loyale and Justy models will remain using the previous R-12 systems. Keep this information in mind when servicing or diagnosing Subaru A/C systems.

R-134a is now the refrigerant of choice. This product does not contain suspected ozone depleting chlorofluorocarbons. The chemical compounds and molecular structures of the old refrigerant R-12 and the new refrigerant R-134a are completely different. However, the temperature/pressure relationships of the two are very similar.

R-134a and R-12 are not compatible. Under no circumstances should they be mixed.

If you suspect that a refrigerant system has been tampered with or may be contaminated, observe the following general rules.

Symptoms of a contaminated system may be any of the following:

High system pressure (could be extreme) the higher the mix of contamination the higher the pressure will be.
Poor cooling
Rapid cycling of the compressor

Inspect for:

Correct condenser fan operation
Debris in front of the condenser
Correct blower fan operation
Charge/caution label
Service ports, stripped threads (from wrong fittings)
Cloudy, milky sight glass

Contact customer for:

Repair history
Dealers, independent shop repair.

It is very important that refrigerants be handled properly. Always wear protective gloves and goggles. For your safety and the safety of others, it is imperative that the work area is properly ventilated. If a refrigerant release occurs, wait until the mist clears before continuing. R-12 and R-134 are to be handled separately. The two (2) refrigerants cannot be mixed. The lubricating oils that are used in the R-12 and R-134a systems are incompatible. Service tools cannot be intermixed. If you find yourself not sure of what to do when servicing an R-134a system, don't guess. Refer to service manuals and service bulletins. As with all automotive repair work, good service depends on good diagnosis.