[dshepp806]

I just recently went through this on my 89,..she's as stock as they come, R-12, for sure. It's no secret that these stock systems are marginal, at best and many discussions have been rendered about what's needed to make this system perform better.

Back to recharge (and I'm NO AC expert by any means, but there ARE many who ARE experts who run within this NG....)

In my case, i blew the high pressure hose from the compressor to the rear condensor. Clearly, at that point, I had an "open" system that would need a fresh AC/dryer and new High Pressure hose. I had no interest (or, should I say, "intention") in any upgrade approaches (,..maybe later). My question became how much freon would need to be loaded and how much oil would need to be added. The Bentley has a great breakdown as to the oil for each subsystem, as well as the total system capacity of R-12. We made a call on the oil amount needed (old school mineral oil, BTW) then prepped our R-12 cans (knowing the system capacity spec was 47 oz.). We pulled a vacuum for 2 hours,..then removed to watch the hold state...she held it for about 50 minutes and we were convinced all was well with a no leaky situation. We loaded 3 cans,..nice and slowly,..then pressed on with can #4. All while watching our pressures and monitoring vent temps. We called it "a day" after a partial load of can #4. I continued to use the car for another week, closely monitoring temps to see how she would do in the cooler AM times,..then when challenged with +100 degree ambients. Definately a range there. after one week, we rechecked our pressures and focussed on the sight glass (bubbles),..determining that we would add a small bit more, having seen a few bubbles in the sight glass of the NEW AC-dryer. This amount was added, to the point of NO bubbles and acceptable pressures, considering ambient temps (as mentioned: there exists a scale one would need to follow that's dependent upon ambient temps. In the end, I'm OK with what we achieved, albeit FAR from killer specs (I don't think you'll achieve "killer" with stock setup......I made sure (front-end) that my condensors were WELL cleaned and used a sniffer everywhere I could to CONFIRM I had no leaks.

In the AMs, when the ambients are much cooler than at 2 PM, she can put out 44 degrees at the center vents,..however, on the mid day checks (+100 degrees out), she will do well to turn 56 degrees to 58 degrees. I've removed the bowtie down below and am studying how I'd like to route this respectable amount of air volume upward into the cabin instead of blowing it downward to the feet area...I'm seriously considering removing my CD holder assembly and installing a vent there to make use of this source of air volume in a MUCH better way.

Overall, I'm content with where we are , for now......I'll look at mods later......for now she's keeping me comfortable (compared to NO AC-easy to please, at this point).

I WILL say this: you definately DON'T want to overcharge her or you won't have a fighting chance as to performance. Just because the system capacity spec is some degree of ounces DOES NOT mean you need to add THAT specific amount, hell or high water....I'd focuss on pressures and vent temps,..along with watching that sight glass.

As you probably already know: should you NOT have a nice big fan to provide air across that rear condenser, you best keep the lid closed or you will up the probability of damaging your compressor,..better pay strict attention here.

BEST!

Doyle


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