Some have used the Interdynamics conversion kit just as it says, not replacing any parts and just revacuating and recharging. Some say that they've had good luck with that process, but I've heard more horror stories than success stories. The guys that do a/c for a living suggest replacing the accumulator/receiver-dryer, o-tube or expansion valve, dumping all the oil out of the compressor, changing all the seals, THEN use the R134a conversion kit. There are good reasons for doing all of this, which you can find out about if you visit this a/c bulletin board below and check through the archives.