Expert: Skip Bollinger - 6/23/2007

Question
had a/c serviced no leaks detected but after a feew weeks the a/c is blowing warm again. not sure what refrigerant is used on this vehicle everything is still factory i was going to recharge it myself it is R-134 and see what happens before i spend more money

Answer
Brian,
  I would like to begin this response with this: I'm a parts specialist, NOT a tech. Okay??? Now, I have gotten other questions before this one but am answering them in the order of which I'm able. I have one that I will have to contact coworkers on Monday so, while it was first, it will be answered last. To that person, I'm not ignoring you, I just want to get the best information about your ABS problem. Please be patient. With that being said, let's move forward with the other questions... Thank you for understanding.
Again, Brian,
  I'm at home and don't have the literature to look up what type of freon your truck takes but I would imagine it would be R134. You can look on the evaporator case under the hood and see a decal that should tell you. You can look at the charging ports also. If they look like they have the threads of a tire valve where you put in the air, it is R12 and you will need a Federal License to purchase it. If they look like 1/2" aluminum fittings with a groove around them, they are R134 and you can purchase this freon from any parts store.
  Now to the leaking problem. Do you know how they checked the system for leaks?? The most obviously hidden place for an A/C system to leak is the evaporator core. It is not obvious since you can't see it. It is hidden by a  fiberglass housing. Did they use UV dye or a "sniffer"? You said you had the A/C system "serviced and no leaks detected". Do you know what type of leak detection was used?? UV will show obvious leaks but if they can't see it, it won't show. As I said, the evaporator core is hidden and only a "sniffer" will show that leak.
  I hope this helps. Good luck.
Skip