Still locating shop for recovery.

Please explain your comment on flush/no flush condenser considerations…

Sticking with R12.

Low side port is schrader valve on head adjacent to line connections.

I’m starting to get the feeling the only way to correct this is to flush the system. Is it preferred to remove the expansion valve, disconnect the lines at the compressor and flush through the evaporator, condenser, filter/drier and not the compressor?

No, this replaced the original piston compressor. Sight glass went from foam to foggy/clear eventually. Those pressures stayed in that range under tests similar to your suggestion at 85 degrees 55% relative humidity. No vent readings per say, but very cold at idle to warm air under load.

Generic knock off, not genuine Sanden. Charged from 14oz cans from manifold gauges into charge ports on compressor. Added quantity drained from old compressor.

No.

5 oz Ester. Yes, exactly. That’s what I would have expected.

Specifics; 1974 DeTomaso Pantera. Replaced York with Sanden SD508 compressor, new expansion valve, filter drier. Vacuumed down. Charged with 2 lbs R12. Low side 25, high 125. Drove a little, cold at idle, went hot while driving. Went to add more R12, now low side 75 high side 130 at 88 degrees 50% r...