I looking in to converting my ac to 134. It colls but not well anymore. This will be a new venture for me. I saw the kit at walmart. Anyone have any suggestions for me.

You could try adding refrigerant to your existing system. Freeze12 is a freon replacement you can buy in a lot of places. It is the cheap fix. Try it. You need freon if there are bubbles in your sight glass when the A/C is on highest setting and the fan in your car is on high.

Normally, when you fill a system (in regard to your conversion suggestion) you evacuate it to remove air and water from the system. I don't understand how you could do this with a kit from Walmart. I suspect the cost of the conversion kit doesn't include the cost of evacuating and filling the system (forgetting installation).

The conversion kits really only supply fittings to go on top of R-12 valves. And all you are doing is topping off with R-134a instead of R-12, which usually will work just the same, using a little less.

Freeze12 is just a 80%/20% 134a / 142b blend, nothing special.

can you mix r12a with 134a ?

They will mix. It is not really legal however because it contaminates the freon so it can't be reclaimed. If you choose to do it do not ask a mechanic to evacuate your system afterwards. The new oils are compatible with both refrigerants.

I did this conversion to my 88Camry and wasn't really happy. R134 just does not do the same cooling job as R12. Mine works okay when its not real hot out. But when its real hot (90-105 degrees) I must run it in Max cool and it will keep it cool as along as I'm moving. Servicing really doesn't help my system cool any better.
JJ

I did the conversion to 2 of my vehicles last year. Both systems are low on freon and didn't cool well at all. And the old type of freon is so expensive, I just decide to convert it. The results are pretty good so far, the outlet temperature is below 50 degrees. I replaced the receiver/drier. Then asked a local shop to evacuate the system for $30 (2 times, one before I replaced the receiver/drier to get the remaining freon out, one after I replaced it to get the air out). Installed the adapters and charge R134a to about 80% of the capacity. I don't think it's a good idea to mix 2 different types of freon. The lubricants are different and don't go with each other.

Do NOT buy one of those R134 retro kits from Wal-Mart or Autozone if you like your car.. those kits cause "black death" to your A/C compressor and all of the aluminum components of your AC system.. the additive does not mix well with R12 oil in the system and your A/C compressor will starve for oil and wear out since R134 does not carry the oil through the system very well if at all. That is why R134 needs specific oil that will flow the oil and the R134 through the system and back to the Compressor again.. the R12 and R134 oils do not mix.. period.

Do some research on the subject with the below links before you decide on the retrofit.

Alt Refrigerants Board - no longer posting, but a good source of info on alt Refrigerants:

http://www.aircondition.com/wwwboard/alternative/

R12 - R134 only board:

http://www.aircondition.com/wwwboard/index.htm

http://www.ackits.com/forum/index.cfm

A/C Parts - Tools/Message Board:

http://www.ackits.com

http://www.acsource.com/index.asp?PageAction=VIEWCATS&Category=260

My first choice would be that it is probably just a little low on R-12, I would just have it topped off with r-12 again for the $50 it will cost for a lb of r-12.. you will be much happier than the R134 retrofit, having tried a couple of retrofits for friends and in my 78 280z, I went back to
r-12.

If you are determined to retrofit, don't retrofit to R134, that stuff does not cool well in an older system designed for R-12 because R134 does not displace/transfer heat well and the older systems have a small condensor/ac radiator in the front and cant get rid of the heat. To correctly retrofit to R134 to work well you have to replace the condensor to an oversized one like the new cars have, flush all of the old R12 oil out of the system, add the correct amount of R134 oil, replace the water/separator to an R134 unit, remove the compressor and get all of the old oil out of it by working the r12 oil out with the r134 new oil, evacuate and charge in the R134.. then there is no assurance that it will cool as well or well enough to get by even.

I have tried freeze 12.. it works about as poorly as R134, because it is 80% R134. I have tried all the alternatives ES 12, HC 12, I even charged propane into the system which did not cool well enough when it got very hot outside - and yes its flammable, but so is R-12 and mineral oil.. the R12 and oil mixture is probably more flammable under pressure than the propane. After a year or so of research I did find a substitute that actually works better than R12, I just charged the gfriends Honda with it and completely happy. It is compatable with the R12 oil and is a legal drop in replacement for R-12.. Most shops only know to use either R12 or R134, but there is an alternative called "Autofrost":

http://www.autofrost.com

The people on the A/C message board dont care for "Autofrost" so don't bother posting questions about it.. I can say that it works very well, honestly better than R12. The only downside is that it is a mixture of two refrigerants so if you have a leak one will leak faster than the other (fractionalism) since one is a lighter gas. It does not sound like you have a leak though since it is still somewhat cold.. even R12 will leak a little over time this is normal, you should run the A/C once a week to keep the seals moist. This will help keep it from leaking.

You can get certification to buy R12 or Autofrost, I did.. it takes an hour and is an open book/online test and you get your cert right then and there for the $20 or so as I remember. There is a link on the autofrost page for the "EPA Certification" then you can buy the R12 or Autofrost depending on which way you go at:

http://www.refrigerantsales.com/?

R12 is about $29 a lb right now and that is about the best price I have found. Autofrost is less than $8 a lb if you buy a case (12 cans) at a time.

Anyway, do the research on the posted links I gave you, it will take you a while to go through it all.. good luck!