CAUTIONARY POINTS FOR MAINTENANCE
G-4spec tableThis vehicle uses R-134a refrigerant; R-12 and R-134a parts/tools are not interchangeable.
REFRIGERANT-134a (R-134a)
Outline
R-12 and other fluorocarbons now used in air conditioners can destroy the ozone layer in the stratosphere. The result is an increase in hazardous ultraviolet rays which over time can adversely affect both human health and the biosphere. Because of this concern, Mazda has chosen to use Refrigerant-134a (R-134a), a hydrofluorocarbon-based refrigerant that does not deplete the ozone layer, in this vehicle.
R-12 and R-134a are not interchangeable; system parts and system service tools also differ. The table below compares the two systems.
Refrigerant systems
Refrigerant systems comparison
Refrigerant
R-12 systemChlorofluorocarbon-12 (CFC-12) (CCl2F2)
R-134a systemHydrofluorocarbon-134a (HFC-134a) (CH2FCF3)
RemarksIf the refrigerants are mixed or one refrigerant is used in a system that requires the other, the compressor oil will separate from the refrigerant and not circulate within the system. This can damage the A/C compressor and cause abnormal A/C compressor vane noise. In addition, mixing R-134a with R-12 or using R-134a instead of R-12 in an R-12 system can lower the durability of the NBR O-ring and dissolve the fluorine rubber O-rings. If the fluorine rubber O-rings are dissolved, refrigerant may leak.
Compressor oil
R-12 systemMineral oil
R-134a systemPolyalkylene glycol oil (PAG oil) [ATMOS GU10]
RemarksSpecial compressor oils for R-134a air conditioning systems are developed by each air conditioning vendor. Therefore, use only the specified oil for each model vehicle. If a PAG oil other than the specified type is used, the A/C compressor and refrigerant system can be damaged. If the compressor oils are mixed or one compressor oil is used in a system that requires the other, the compressor oil will separate from the refrigerant and not circulate within the system. This can damage the A/C compressor and cause abnormal A/C compressor vane noise. Mixing PAG oil with mineral oil or using PAG oil instead of mineral oil in an R-12 system can lower the durability of the NBR and fluorine rubber O-rings.
O-ring
R-12 systemNitrile butadiene rubber (NBR) Fluorine rubber
R-134a systemHigh-circulated nitrile butadiene rubber (HNBR)
RemarksIf an NBR O-ring is used in an R-134a system, the PAG oil and R-134a will lower the durability of the O-ring. If a fluorine rubber O-ring is used in an R-134a system, the R-134a will dissolve the O-ring and cause the refrigerant to leak.