Well, after a TERRIBLE day with my upgrade/retro fit, here is my update.
I still have 2 cans of Freeze-12 and no easy way to introduce it into the system. The can threads are different than the can tapper I have (assuming its probably an R-12 thread). My search today to find a can tap for R-12 led me endless and frustrating conversations about how its illegal to sell it to me without a EPA/Clean air act certification number (bah!)... I might have an old one from the 80s somewhere in storage, but my patience ran out long before it had a chance of being discovered.
So.... I went for the popular R-134a alternative with a hesitant sigh. I used 2 cans of an advertised new mixture called Arctic Freeze. Has some sort of claim of development from NASA to work better and faster then the standard and its marketed as R-134a+.
My system had NOTHING in it so I changed the two "O" ring seals on the compressor fittings and started a deep evacuation of the system. I used a pneumatic venturi style vacuum pump and brought the system down to 22 inches of mercury. I closed off the valves and went for parts. After several frustrating trips for tools and refrigerant (since I could not get a can tapper for R-12) I continued on the project almost 2 hours later. The good news here is that when I returned, there was still 22 in/hg of vacuum on the system, thusly giving me confidence that there was no serious leaks to attend to.
I had trouble in my adventures finding a can tapper the was decent for R-134a and settled on a cheap $13 option that had a gauge, can tapper valve, and a quick connect to the low side of a R-134a valve. Note here: BAD MISTAKE! I really wanted one that I could use with my manifold gauges and service hose, but the parts stores I visited wants $35 for it. So I tapped the can with my intentions of a clean first can injection. NOPE. Remember that word cheap from before. The plastic valve outer body broke after the can was tapped and I ended up loosing my refrigerant and my temper. After a brief call to my counselor Earl (ensteele), I was able to regain my calm and go back out in 97 degree heat for my 4th parts run of the day.
Autozone is your friend..... so I hear. This nightmare started at noon and now its almost 9pm. I don't drink beer, but I am contemplating the reality of beer=success. I hit Autozone in time and get directed to a small display of refrigerant and supplies. I notice the very same cheap $13 system that broke and put me here for alternatives and rationalize the realality that the same set up here is the same price..... uhh. unlucky number 13. I just about throw in the towel when I spot a professional commercial quality, brass can tapper that is made to work with the service side of a manifold gauge set. YEA! And its only $5.99. (note to self, 13 is indeed an unlucky number, and there actually is a god).
9:30 pm, starting to get dark, still butt hot outside and I am FINALLY starting to introduce refrigerant into the system. I put in a small can of PAG 46 oil, followed slowly by two cans of Arctic Freeze R-134a+. I watch my pressures on both the low and high side. Thirty minutes later the system seems to have stabilized with my low side at 30psi and the high side at 190psi.
Moment of truth. I walk around to step into the inside of the car to see if I have accomplished something good or if I am going to kick the crap out of something. When I started the car and turned the A/C on, I put an atomic clock with temperature on the center console since I don't have a stem thermometer handy (note I will get one tomorrow and post my results). With the outside air at this time of night at 85 degrees, I got into the car and closed the door..... Burrrrrr. Temperature on the clock says 66 degrees. YEA!
The real test comes tomorrow. Forecast for tomorrow is 101 degrees. Earthworm swears that when he came here to visit, his shoes were melting to the asphalt. I do not remember precisely but I think it was like 105 that day. So, I will hit up Wal-Mart or Harbor Freight for a cheap stem thermometer and post how well my actual project works. I would post pictures, but they would just be too violent!
If after a few weeks all feels well, I will offer my assistance to anyone in the area whom has an R-12 SVX and does not want to be raped $70 a pound for R-12. I can also top off any one else's SVX that uses R-134a as well.
(Next person that tells me I cannot work on my R-12 system gets popped in the jaw!) Besides, its not like I evacuated or dumped any R-12 into the atmosphere nor introduced more into my system. Freaking government donkeys!