67 GTO and 69 Caprice AC

[klittle]

I have a 67 GTO with factor AC and a 69 Caprice with the factory Comfortron AC system. Both had the oil changed years ago and 134 charged to the systems. The GTO had a new compressor and drier. The Caprice had a new drier and expansion valve. No other changes were made to the systems and the POA valves were not recalibrated. Neither car ever cooled well and frost would appear on the line from the evaporator to the expansion valves.
I just tested the Caprice POA with air and got no resistance or pop at 30 PSI. I haven't checked the GTO yet. My hopes were to recalibrated the POA valves and recharge the systems.

Question....should I purchase a recalibrated -134/rebuilt POA for the Caprice, change to a POA eliminater kit or the newer billet POA eliminator? How about the GTO?...try to recalibrate or follow suit like the Caprice? I know the air flow and cooling won't be like a new car, but hopefully much better than the last several years

TIA for any advice.

[bohica2xo]

If they still have the A6 compressor, recalibrating the POA valve for 134a should help a lot.

Older conversions sometimes have too much (or mixed) oil in the system because of the guidelines used 30 years ago.

The other thing that can make a big difference on older cars is the fan clutch and shroud. The old tube & fin condensers need a lot of air flow to keep up.

I don't recommend the eliminator kits because the A6 was never designed to cycle.

If your POA is wide open at 30 PSI on a bench test it sounds like it is stuck.

[klittle]

If they still have the A6 compressor, recalibrating the POA valve for 134a should help a lot.

Older conversions sometimes have too much (or mixed) oil in the system because of the guidelines used 30 years ago.

The other thing that can make a big difference on older cars is the fan clutch and shroud. The old tube & fin condensers need a lot of air flow to keep up.

I don't recommend the eliminator kits because the A6 was never designed to cycle.

If your POA is wide open at 30 PSI on a bench test it sounds like it is stuck.

THanks for your input! Yes, both of them still have the A6 compressors. The 69 Caprice is the original, the 67 GTO had a rebuilt one installed about 20 years ago. I was having the same thoughts on the eliminator kits and the A6.

Hopefully the GTO POA will be OK. I was seeing that the POA should be recalibrated to about 26 PSI...is this correct? Looks like I'll have to purchase a rebuilt one for the 69 Caprice.