1995 GMC Sonoma Owner's Manual - Page 288

Air Conditioning Refrigerants Not all air conditioningrefrigerants are the same. If the air conditioning system in your vehicle needs refrigerant, be sure the proper refrigerant is used. If you're not sure, ask your GM dealer. For additional information, see your "Warranty and Owner Assistance Information'' booklet. Air Conditioning Refrigerant Capacity TYPE R- 134a "All quantities are approximate. QUANTITY" 30 oz. ( 2 5 kg) or 2.0 lbs. (.91 kg) NOTICE: R-134a refrigerant is not compatible with R-12 refrigerant in an air conditioning system. R-12 in an R-134a system will cause compressor failure, refrigerant oil sludge, poor air or conditioning system performance. 6-70