* A/C system size: Different Caprice models and options might have slightly different capacity A/C systems.
* Leaks: If the system has leaks, it will require less refrigerant than a fully sealed system.
* Condenser and Evaporator condition: A dirty or damaged condenser or evaporator can affect the system's efficiency and refrigerant charge.
You should NOT attempt to determine this yourself. Improperly charging an A/C system can damage the compressor and other components. R12 is also being phased out due to its harmful effects on the ozone layer. Modern refrigerants require specialized equipment and techniques for handling.
Instead, consult a qualified automotive air conditioning technician. They will properly diagnose your system, repair any leaks, evacuate the old refrigerant, and charge the system with the correct amount of refrigerant (likely a R134a conversion kit, as R12 is no longer legally available for recharge in most places). They have the necessary tools and expertise to do this safely and effectively.
