Added AC system - Need help with freon choices r12 - r134a

[bighause]

I finally finished the process of adding factory air conditioning to my truck and I'm ready to have the system evacuated and charged. I got all the parts out of a 89 Cherokee and replaced the drier and all the orings.

 

Being an 89 it was running R12, I'm not sure what to charge it with. Everything I've read tells me r134a in a converted system will not cool as well as R12 due to the condenser size differences. I've read a little about Freeze12 and I'm not sure if that would be a better choice than r134a or not since it is mostly 134a with some additives.

 

Anyone recommendations or first hand advice? Summer is nearly here in Texas, I need to get it charged soon.

[Backdraft]

I ran the Freeze 12 in a 90 XJ and was happy with it. Air blew nice and cold.

[Comanche1987]

freeze 12 is r134a with propane or some other gas mixed. It should not be difficult to locate the correct size hose fittings and a r134a condensor to connect to your system. I work on custom a/c systems in school buses all the time and they are fairly simple, a simple crimped connection to the correct fitting, a/c hose can be purchased at most autopart stores I believe too. I have used r134 with stock r12 systems, its hit or miss, some systems its ice cold others it isn't.

 

I definatly would not use freeze 12, I noticed no difference except price and a little lower pressures, but not enough to produce a temperature difference.

 

If you charge it with R134 and it doesn't leak your system is in good shape and you can look for some r12 (searchtempest.com click autoparts catigory, enter "R12" into search 0-150$) on craigslist.

[JeffN]

I would be wary of R-12 unless it is brand new sealed container. Alot of people are selling recycled R-12 that has been known to be contaminated.

I got the R134 conversion kit at napa and it worked perfectly.

You just have to make sure your system is fine and make sure you have the proper amounts of oil in the proper places or it will not last long, I am not sure if your drier requires oil since I don't have Alldata available here at home.

[bighause]

I have access to proper r12 and r134a gauges and a vacuum pump so I will be pulling vacuum on the system for several hours to make sure I don't have any leaks. I don't want to waste money on buying refrigerant twice and I'd rather not pay for another condenser since I have a good factory one already.

 

I was originally planning on just charging it with r134a once I'm sure there are no leaks, but I'm concerned it may not cool properly. Maybe I'm over thinking this?

[Jeep Driver]

r134a in mine and it works fine.

[mvusse]

I changed my Geo over from R12 to R134a and it cooled just as well after the change as it did before.

[nitroxsteve]

134A in my 88 and it works fine.

[bighause]

Are you guys running 134a without changing the condenser or anything else?

[JeffN]

Yes, I just put a new drier on which should be done whenever you crack the system open

[Gjeep]

BigHause- Glad you got everything wired up. I'm the guy the provided you some diagram assistance with that. I can't remember if we also talked about the R134 conversion. I did some research on this way back when I was going to run the Renix R12 ac system with 134a. Know that you really should have converted to "barrier" style hose to run the new refrigerant, but old R12 hoses should work well enough since the R12 coats the inside of the hose after many years of service and provides a barrier of sorts. R-134a compatible seals or o-rings are hopefully what you replaced the originals with, inaddition to coating them with Nylog O-Ring Lubricant during assembly. You also need to swap out the oil that's in your compressor (BVA100 ester oil recommended). Critical for compressor life expectancy running 134a. Check out/ search ackits.com forum. It's a great resource.

[bighause]

GJeep, I very much appreciate the time it took you to put together the wiring info you sent to me! I never would have gotten it figured out without your help. I worked on this a little at a time and can't wait to get it finished in the next few weeks

 

I do have the correct orings and will be coating them before assembly. Thanks for the tip on the correct oil, I'll be sure to swap it out. I do have a new also drier that I'm installing once I get ready to charge it.

 

Looks like I will use 134a after all, thanks for the quick advise from everyone. I'm sure with the small cab It'll get plenty cold in there

[Comanche1987]

This sounds pretty crazy and is illegal but I thought I'd share,

 

there is a guy I know that has repaired his a/c system without any real equipment, crazy.. yes you really do need to see the high side pressures but anyways... I've seen him replace a compressor and drier on a mid 90s r134 ford truck and since he had the system open it had oxygen and what not, he demonstrated charging the low side with a diy kit and then with the shredder valve down on the high side let all of the r134 force the air out.

 

I've never done this and I don't have much experience with diy r134, I have been trained on robin air machines at work and know enough about air conditioning to know better though :rotf: