1979 A/C re-charging

The gauge faces should be labeled for R12, or 134, or maybe even R22. You'll need to look at the lettering where the numbers start in the circle...it will usually be R12 on the outer circle, and the other types(R22, 134, etc) on the inner circle. Not all gauges are the same, so I can't tell you what yours has.

What pressures do you see on the gauges when you hook them up,  without it running, and running?(all valves closed)

Gauges are marked, it looks like the very inner red scale is mark R22 & R12, a double scale.  The next red scale is marked R502 this one is in the middle.  Black scale on both are not marked, most outter.

The high side only goes to 200psi??? Wow...that's not gonna give ya much to go on...
Could you get a pic of the gauge faces?

Just wanted to say thanks to everyone that helped me get my A/Ccool again.  A big special thanks to Joel Adams.

That's great..I guess you need AC down there all year! Hopefully you can remember how this all goes for the next top off! I haven't charged a car with a little can in a long time. Got any of that R12 left for next year? That stuff is getting really hard to find in those small cans! We can get that Freeze 12 stuff but we don't for obvious reasons! Drive cool.
Rich

O, I took good notes.  Pretty cool down here right now.  R12 was easy to get but pricey, $29 for a 12oz can.  Too much bad info on the street about Freeze 12.

I don't think that 29$ t fix the AC is all that bad.. I would buy a few extra cans to get you thru a couple of years..who knows how long they will be around! I avoid the Freeze (propane)12 also..
Rich

There is also a product called Frigg 12, which is basically the same crap as the Freeze 12, with different labeling.We had a salesguy stop by the shop one day and gave us a case of it, and said "Try it out, and see what you think".
I actually called the tech support number listed on the can, and eventually got to speak with someone that was supposed to know all the tech specs and such....he didn't know crap...didn't have any idea if it was a complete, SAFE drop-in replacement for R12, or anything else.
Like an idiot, I blew a can in my '74 a  year or so later before driving to an NCRS meet. It took just about 80 miles of highway driving to lock the compressor up, and burn the belt off, before I even realized what had happened. Needless to say, I were NOT a happy camper that weekend.
Any of the other vehicles we used that crap in at the shop also wound up with massive internal damage shortly after....
I will update everything I have to 134 when the time comes. I will not worry about locating, or paying for R12 anymore. I have found that 134 works just as well in most cases, and there is very little extra needed to upgrade to the 134 from R12.

That had to really make you ######off.. I have never used either one..probably never will..body shop had one towed in with minor front end damage that exploded on impact! insurance sued the shop that charged the AC with that stuff..they didn't know it had propane in it! I felt bad for that shop! The car was a total loss..
Rich

It's not just the propane in it....that crap has some other chemicals that will apparently break down the oil in the system. Either that, or it keeps the oil from mixing in, and being circulated thru the system....