Hello All
The 70 Dodge I have has no gas in the ac system. The shrader valve on the high side is covered with a blue cap, usually signifying R134 has been used. However, the fitting on it and the low side is still the same as was the case with R12. I have both gasses. How can I tell if the system was actually filled with 134 (and has the proper oil) or was just on R 12 but the caps were just handy? Any way to determine this?
Thanks
