Just got a "new" 84. Assuming we pass emissions, son and I will tackle the A/C if possible. Does anyone know of a comprehensive article or resource for diagnosing/repairing the A/C? All we know now is that is does not work (and has a belt).

I don't know of one but Robert might. Its basically a very simple system. The only real working piece of a modern A/C system is the compressor. The rest is just gas lines and evaporators/condensers. Gas goes into the compressor and is compressed to a liquid then sent to the condenser to further condense it to a liquid and cool it off. Then its sent to the orifice into the evaporator when the liquid expands, like what happens to the air from a spray can, into a gas state in turn it removes the heat or something like that and it gets cold.

So, I'd remove the lines and flush them out, put in a new dryer/accumulator and an expansion valve (Orifice tube) and see if it will hold a charge. First you'll need to evacuate the atmosphere from the system and at that point you can also see if it shows a leak. If you pull a vacuum on the system, removing the atmosphere, once the compressor is removed or shut off then you can monitor the gauge to see if it holds a vacuum. If it does not then you have a leak. It could be as simple as needing new O rings. If it holds a vacuum then go ahead and charge the system with the 134. My 4th generation takes a 2.2 Lb charge of R12. I had to play with the amount of charge the first time I put the system back together to get it correct. Now, since I've changed to a serpentine setup, I have to remake the lines and re-do mine. I don't remember if I knew just how much charge to put in but you will need some oil also. I think its going to be around 8 Oz. But that I am unsure of if you put in too much oil then the system will not cool or will cool poorly to little and it will mess up the compressor. I do remember Robert saying that the re-built compressors are junk so buy a new not re-build compressor, according to him.

You might use the search here to see if he has already posted this in another post here. I believe that he has a section in the Tech Articles covering A/C. Go back to the Home page and look at the right side of the page.

edit:

Here look at this page for more information.

http://www.necoa.org/modules.php?name=News&file=categories&op=newindex&catid=2

You should be able to find at a automotive parts store or such a

Haynes Techbook
Automotive Heating & Air Conditioning

The number on the book is 10425 (1480). It includes Basic theory of air conditioning system operation, Basic air conditioning and heating system components, Typical automotive air conditioning systems, Service and diagnostic tools, Heating and air conditioning system service and repair, and Troubleshooting. I had always paid someone to work on my ac systems but it seems it got so expensive. I have more or less taught myself and learned how the systems work inside and out so I do all my own ac work now.
We have a 79 El Camino that started giving problems with the older style capillary tube cycling switch and instead of replacing it I removed it and used the pressure switch that goes on the accumulator. You also do not need the low pressure switch which is in the back of the compressor on the 79 model.
Also you can get a shop manual for you El Camino it has some good information on the a/c system.

Eddie

use the GM troubleshooting guide manual