If you change your car refrigerant R12 to R134A do have the AC compressor?

No, you generally do not need to change the AC compressor when converting a car's refrigerant from R12 to R134a. However, it's crucial to understand that a simple refrigerant change is not enough. R12 and R134a have different properties, and a proper conversion requires several other modifications:

* Oil Change: The compressor oil used with R12 is incompatible with R134a. The oil must be completely flushed and replaced with R134a compatible oil.

* O-Rings and Seals: R134a requires different O-rings and seals than R12. These should be replaced to prevent leaks.

* Expansion Valve/Orifice Tube: Depending on the system, the expansion valve or orifice tube might need to be replaced or changed to one designed for R134a. This is to ensure proper refrigerant flow and cooling capacity.

* Possible Leak Testing and Repair: Before conversion, a thorough leak check of the entire AC system is essential. Any pre-existing leaks will be exacerbated by the conversion process.

In short, while the compressor itself might not need replacing, a significant overhaul of the AC system is necessary for a successful and safe R12 to R134a conversion. Attempting the conversion without these modifications can severely damage the AC system and even the compressor. It's best left to qualified professionals with the proper tools and knowledge.