Colo. Newbie & AC question

[john]

Welcome to the board. If the water shutoff valve is not working you will get warmer air.

[hvychve]

1st, let me say welcome aboard, from southern caly.

I would agree w/ mrein on the sight glass issue, but if its real low you wont see any bubbles, you have what is know as a poa (pilot operated absolute valve) with an expansion valve back up. these systems were awesome when working right and fulll of charge.
Back when these systems were made, mileage was not a factor so size of the condensor and evaporator core were huge , thus in turn you obtain a real good working a/c,
I once loaned my truck to a buddy on a hot day, he came back and told me , that he had to turn the a/c blower speed down, it was freezing his knee.
I have a 72 w/ factory a/c and it has always blown very cold, as a matter of fact I have changed the hoses and the poa valve and the dryer and expansion valve, only because I was restoring and wanted it pretty and no problems later on.
freon is a brand name, R-12 is proper name, diclorodyphloramenthane), I was also going to retrofit it at one time, but after several classes, I have found that the molecular structure is much finer in R134A and that it would seep through the front seal surface of the 6 cyl compressors that are original on these trucks, the seal structure is a porcelin type that seals through a smooth surface contact and that using R134 will just over time leak out.
I have been challenged on this theory before , I am not intending on stepping on any toes, its just what I have heard and the classes I went to .
I suppose a person could try it , remove the R12 and retro it to 134 , the cost of R134 isnt as bad as R12 , so if it leaks out , not all that expensive.

To answer your questioin, yes these systems , if original , should blow real cold if properly charged and working order. no restricitons across the condensor, valves all in good working condition and belt tight and compressor not worn out.
good luck, and by the way , nice lookn truck.