Be careful with that stuff! Hope they did all the proper retrofit requirements and not just a "drop in" charge! A dealership SHOULD know better than that!
Read on.......
FREEZE 12
ASU =ASU = acceptable subject to fittings, labeling, no drop-in, and compressor shutoff switch use conditions
Reviewed:10/16/96
Manuf.Technical Chemical 800-527-0885
Freeze 12 is a blend consisting of
20% HCFC142b
80% HCFC134a
From the
Certification Training Manual
Refrigerant Recycling & Service Procedures
For Automotive Air Conditioning Technicians
*approved by US EPA for technician training requirements under section 609 of the Clean Air Act.
Download the manual here:
http://www.macsw.org/pdf/CertmanualENG.pdf
Pages 22-24 of manual.
quote
There is no assurance that the A/C system will provide the same level of performance with the processed blend refrigerant as it did with new refrigerant containing the proper blend formulation.
Systems charged with blends may provide a high level of performance
when initially charged. However, each refrigerant in these blends has a different pressure/temperature relationship, and different leakage rates through flexible hose. These blends can separate while in use,
and a leak in the system can allow just one component of the blend to
escape from the system. This partial leakage can change the entire
refrigerant mixture and cause system operating problems.
Blend refrigerants contain more than one refrigerant, and have a bubble and dew pressure value
that affects A/C controls. This bubble and dew characteristic of blends results in a temperature difference across the evaporator and condenser known as “glide.” The auto industry doesn’t design
automotive A/C systems to use blend refrigerants. Installing blend refrigerants with the original A/C system refrigerant controls (expansion valves, pressure controls) could cause system performance problems. The automotive industry has always used single composition refrigerants such as R12 and R134a.
Page 26 of manual quote:
System Changes
Changes were required for HFC-134a systems to assure performance equal to systems using CFC-12.
Changes include new hose and seal materials which are compatible with the new refrigerant and lubricant. This includes new hose construction to reduce hose leakage, and a new desiccant material in the accumulator or receiver/dryer for reduction of moisture level in the system.
The most noticeable change, however, is the increased condenser capacity, or increased air flow, to reduce system pressures at low speed operation and city traffic conditions. In general, condenser performance has been increased by approximately 30%, which results in comparable performance for HFC-134a systems as experienced in CFC-12 systems.
http://www.epa.gov/ozone/title6/609/609.html