Not much oil found???

[Jima]

I have a '78 Continental with 460/7.5 engine. When I got it, it had an aftermarket compressor that matches the horizontal compressor shown for six cylinders in the 1978 Ford shop manual. The system has R134a connectors on the lines so I assume a previous owner did a (half way?) conversion from R12. Last Fall the evaporator was freezing up reducing air flow till the AC was off for a while. I doubt the POA valve was recalibrated for R134a so I contacted Classic Auto Air to do that. They suggested a POA Update kit, with pressure switch to cycle the compressor, which has been installed. While attempting a recharge, the suction line pressure was so high not much would go in. Decided to do a complete flush to know what the system contains.

No oil was found in any component other that the evaporator. Nothing came out of the compressor drain plug. Nothing from the condenser. The shop manual calls for a total of 10.5 oz of oil but I'd guess we only got about 2 oz from the evaporator. No surprise that none in the drier since it mounts upside down with the connectors pointed down. Compressor turns easily and smoothly when off the car.

The plan is to finish the flush and reassemble the system with 10.5 oz of PAG. Anyone see anything unusual here? Am I on the right path?

Thanks.

Jim