Re: Aircon pump...
FYI the air conditioner in a Toyota Prius (NHW20 onwards) is all electric. It's actually quite a feat of engineering because it's totally sealed with the motor coils sealed inside the unit with the refrigerant. So you do need a special gas with zero conductivity, but there's no drive shaft seal to leak it away again, so it should stay good for many years. Mine's been going 11 years now without a refill and there are no problems - works fine.