No matter what HVAC system you work on a proper vacuum is essential. You must have a vacuum that pulls down (and holds) to 500 microns or less (A micron is a unit of measurement starting from a perfect vacuum, i.e. no pressure, that is expressed in linear increments. One micron= 1/25,400 of an inch.). If you don't start with a proper vacuum you'll have nothing but problems, i.e. your A/C won't blow cold because of moisture, non-condensibles in the system, or leaks. R134A is R134A. Whether you buy it at the auto parts store in a baby can or from a wholesale refrigeration supply house in a 30 lbs can.

 

Just an update for everyone. I found the following piece in my truck, went to the hardware store and bought a bolt to put it back on, and now have A/C in my truck again. Looks like I just lost the hub from the clutch. Thanks again for all the help!

 

Happened to me. Oreilly's has clutch assembly for about $100. Mechanic told me this is common on these trucks.