1971 A/C What do I have?

[Hack71]

I need some help or advise.
My Truck sometime before me was converted to you 134a, the only reason I know is by the different fittings. When I bought the truck the A/C blew warm air. It had pressure not sure how much though. I evacuated the system (my own pump and it held at -30, +1 or - 1. turned the pump off and watched for 3-4 hours it held with no leaks, I installed new oil and about 3.5 lbs 134a approximately. The a/c was notably cooler, so I thought it just needed the recharge. The first couple of warm days, not hot maybe 85 and sunny it would not keep the truck cool the vents were still blowing cool air but not cold, I never put a thermometer in the vent for the actual temp. Last winter I tore down the truck to do various repairs as noted in my build thread, the a/c was disconnected and removed (still was charged). My thought is either go back to R-12 or continue down the path of 134a, I have heard talk of replacing the condenser with a larger one and the expansion valve being replaced with a POA valve and or adjusting the pressure on the POA to a lower setting.
I'm not sure what I have so I have attached a picture. Any help or input would be great!! also heard that I will need to replace the o rings and rubber lines because of the different oil. Trying to save a buck! If money wasn't an object I would just replace it all! I believe what I have is useable stuff.

[F.A.A.benny]

From your pictures, the expansion valve, hoses and possibly the compressor were replaced. Can't really tell if anything else was changed by the pics. Not sure if they recalibrated the poa valve. You can go either way. for r12, change the expansion valve , hoses, drier, and have the poa valve checked to make sure it is calibrated for r12. Flush the rest of the parts and use correct amount of mineral oil. For 134a, change the condenser, drier, and check to make sure the poa valve is calibrated to 134a. Flush the rest of the parts and use correct amount of pag oil. If you decide to go with r12 and need a correct expansion valve, I have a rebuilt/replated one if you are interested. I can also test/recalibrate the poa valve.

[Davidf]

R134a will struggle to keep things cool inside unless the condenser is replaced with a larger and/or more efficient model as well as having an electric cooling fan in front of the condenser. R134a is not near as efficient as R12 in shedding latent heat from the refrigerant...hence the condenser needs to be larger/more efficient to cool properly. Usually things start to go south quickly at about 95 degrees + ambient temps.

[F.A.A.benny]

You want to change your original condenser with a parallel flow condenser if using 134a. Sorry, meant to state that earlier.

[Hack71]

Thank you for the info, any idea where to buy a set of hoses, I found the expansion valve and o rings and drier, I'm looking for the hoses coming off the back of the compressor and the hose from the expansion valve as well.

[F.A.A.benny]

Old air products has them

[Hack71]

Thank you, looking them up now. PM sent about POA Valve.

[Tdrcreyn4]

FAA Benny - does anybody make a direct replacement parallel condenser for our trucks?

[F.A.A.benny]

Originally Posted by Tdrcreyn4

FAA Benny - does anybody make a direct replacement parallel condenser for our trucks?

Classic auto air and old air products both have piccolo condensers, not true parallel flow but better than original tube and fin type condensers that originally came on these trucks

[67 chevelle]

3 1/2 pounds ? , is that what it calls for , I filled a new nostalgia air system today , it called for 1 1/2 pounds , admittedly its smaller