from the old ac system it was called r12 stopped maken it in 1996 and was completely banned in 2000, now u gotta retofit by law to the new r134a gas,
at our work we offer a test gas and dye, as your only ganna put it in to leak out so no point fully gassing it charge about $60-75 or something, alot of importers know what your a\c system would be like before they degassed them...