I found out the other day while driving that my A/C is not cold so I am thinking it needs a recharge. Am I right to assume this? If so, what R-134a should I use? Any recommended ones?

Also, I did notice when I first bought the car that there was green gel around the cap for where you recharge the A/C. Could this be from them putting the gel in the system, or is it an actual leak possibly? I just don't want to waste money on recharging the system if it's completely not this issue at all.

 

The green is dye that was used to check for leaks.
Must determine that there is a problem with the A/C system and not another part of the HVAC system causing the problem, so best way to attack the problem is to have gauges placed on the system to check for proper "charge", but if low, there is a leak so check for dye in other locations. If low, you can add refrigerant to bring up the charge to where it should be, but after time if charge drops again, there is definitely a leak that must be found before charging again.

 

I would just take it to the right place where they can get the whole gas out of the car, weight it, and put the correct amount back in the car along with this UV liquid. You might also use these gas cans but you don't really know how much gas you are putting into the system and in the same time you might damage it if you overfill. I did recharge my system last year for $60. As far as I remember, the AC system holds 550 grams of gas and my car was at 450 after they got all gas out of the car and weighted it. They put the right amount back and I haven't had any issues since than. I also keep my AC always on, even in the winter. I got into this habit after owning Audi A8 where AC runs constantly to give you fresh air and prevent windows from fogging.

If recharging does not help, then I would look into it deeper.

 

Thanks for the insight.
I did buy some freon refill but looking at the container and thinking about it, there is just so much extra stuff they put in the freon (oil, sealant, "ultra-synthetic"...) that I had to call my mechanic and get another point of view. I think I am going to have the shop do it right with just some good old regular freon.

 

Well, you use just regular refrigerant R134a, no additives. Add the refrigerant and see if it holds pressures. Why discharge, evacuate, add gas and find there is a leak, which there must be if the air is not cold, and then go through the entire process again? Also, in the FSM there is a 2oz range when refilling, 17.+/19.+.
They also lists ambient temps and pressure. I have an old SnapOn R12 recycling machine, so I just use pressures. A friend of mine has a relatively new machine, hook up the hoses, plug in the info, hit the button and the machine will recycle the gas and charge with the correct amount. Simple but costly.

 

Definetily don't have a SnapOn R12...
I would love to find regular R134a, but everything around these stores has a bunch of additives in it. Might have to order some or something...