I have an AC system which has R12 in it and one which does not. The one with R12 is not functioning properly and ordinarily I would bring it down to a local shop where they would "recover" it (i.e. steal it), then charge me to refill the system after I finished up working on it...so here's my thought...why can't I connect the gauges to both systems and transfuse the R12 from the car that has it to the one that needs a charge and effectively recover it myself? If I were to carefully bleed it from the high pressure side of the donor system into the low pressure side of the recepient system couldn't I get most of the charge to move from one to another? What am I missing?

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz