yukon988

I am getting ready to get the A/C running on my '72. For those who have done the r12 to r134 conversion, do you do the POA adjustment as described in this article:

http://www.corvetteforum.net/c3/zwed.../ac/acmain.htm

Do you replace your orginal POA valve with a cycling POA valve (as sold by all our favorite suppliers) or just run the original as is?

Also, my AC system may have been opened for about a decade. There was no compressor or condenser on it when I bought the car. I have aquired a new (rebuilt) compressor and condenser and will get a new receiver/dryer. Should I try to get the system going with the existing POA, expansion valve, evaporator, and hoses (with a flush) or is it wise to replace some of those as well?

PhotoVette1

You should at least replace the rubber hose set--they're fairly cheap.

Open for 10 years? Replace everything. Except maybe the hardlines.

Heck, replace them too.

Cars this old it's better to replace whole systems and assemblies at one shot, otherwise you'll be fixing the same system over and over again.

You wouldn't replace just one brake hose would you? Nope, if one goes its best to change all four.

Even if it takes a bit longer due to cost--it'll just cost you more in the long run if you don't.

Cycling--squeeze every ounce of gas you can--I made my own more procise system for my EEVIR.

yukon988

Photovette1 -- thanks for the advice. The point about fixing the same system over and over is well taken.

SIXFOOTER

yea, I got to agree with Photo. At a minumum you need new flex lines. R134 requires Barrier type hoses because of the molecular size of R134. New R12 type hoses will leak R134 thru the hose itself. Hard lines should be ok, but look the ends over very carefully. When its together pull a hard vacume on it and leave it for 4 hrs or so with the caps on the schrader valves. The book recommends an hour, but that ain't enough. If it loses any vac at all, find/fix it before charging.