I'm attempting to do some DIY car repairs from my driveway, and need to remove the vehicle's AC condenser. To do so, I need to evacuate the r134a refrigerant from the AC system. Apparently it is the norm even at some auto shops to vent this refrigerant into the atmosphere, despite its high potential as a greenhouse gas and resulting legal penalties. I would like to avoid this method.
I've sourced a very old and very cheap Amprobe ProMax RG5000E refrigerant recovery machine, hoses and a tank for the job, and recycling service willing to dispose of it properly, and I have been studying the manual in preparation for the recovery. In doing so, I thought I might as well attempt the self-purge procedure, as I have no way of knowing what was in there before.
The self-purge operation results in a vacuum of ~10 in Hg after ~30 minutes, and doesn't seem to progress beyond that. It does seem to hold that vacuum for at least a half hour after closing the output and shutting the machine off. 24 hours later, the machine's vacuum seems to have returned to atmospheric pressure.
Does this mean the recovery machine has a slow leak? Is this machine still sufficient to perform a typical automotive refrigerant recovery, or will I risk venting a significant amount of refrigerant into the atmosphere?