ml> the lines, the condensor and the compressor are the three main parts...   
   ml> i've seen where the condensor has had to be replaced a few times but most   
   ml> of the time it is either a leak in the lines or the compressor... you can   
   ml> try adding coolant fluid (it isn't freon any more) with the leak dye and   
   ml> use a black light to see if there are any leaks... the compressor, if it   
   ml> is bad, is generally the most expensive part...   
      
   Back when I had an A/C leak in the Monte Carlo, every season I would add more   
   R-134A to the system.  Like all leaks, they never get better - only get worse.   
   I found myself adding R-134A every few months.     
      
   I tried all the black light tests to try and find the leak, but was unable to   
   locate it.  I ended up taking it to the shop, since I wouldn't have been able   
   to properly evacuate and recharge the system once it was opened up, anyway.   
      
   It took them a bit, but they found the leak in the condensor.  It was really   
   tough to see since you can't really get a good look at that area in my car   
   since it backs to the radiator and it was leaking on the radiator side.     
      
   Once that was replaced, all has been well since.  It stays super cold.     
      
   No A/C repairs are really cheap (other than to keep adding R-134A), but the   
   worst one that can happen is if the compressor fails in a way that throws junk   
   in the lines.  Then you have real issues.  Fortunately, that doesn't happen   
   very often.   
      
   - Mark   
      
   --- WWIVToss v.1.51    
    * Origin:  http://www.weather-station.org * Bel Air, MD -USA (1:261/1304.0)