1991 LC. The AC has faded slowly over the last year. IT is an R12 system. I can not get R12. R134 will destroy my AC system. What is FR12 refrigerant? What are my options?
Thanks
Scot
Thanks
Scot
AC system R12 solutions (14 Viewers)
- Thread starter Scota4570
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
ppc
M Go Blue
R134 will not "destroy" your AC system. Ideally R12 is slightly more efficient cooling but the conversion to R134 has been successfully done with many, many vehicles including Land Cruisers.
- Thread starter
- #3
My understanding is that using R134 with the mineral oil already in the system will trash destroy it with sludge. It did exactly that on my 1988 T-bird. It worked about 10 minuets then completely failed. There is a conversion process to use R-134 and it is expensive.
R-134 requires a specific synthetic oil. IT does not play with mineral oil. The dryer needs to be needs to be changed and the system fully purged too. Since I posted I found out that R-406A is a direct replacement for R-12.
R-134 requires a specific synthetic oil. IT does not play with mineral oil. The dryer needs to be needs to be changed and the system fully purged too. Since I posted I found out that R-406A is a direct replacement for R-12.
I “converted” 3 vehicles from r12 to r134 back in the day. All I did was fill them with r134 from an auto zone can and all worked without issues. I know people will wring their hands and talk about dryers and such, my experience is what it is. I paid for no new parts, no evacuations etc. All three systems had slow leaks and required a top off annually, but all worked well and kept the cabin cool.
smritte
SILVER Star
The issue isn't the 134. The issue is if you add PAG oil to it when you convert. The pag oil will react to the chlorine in the system. Fill with 134 and use POE oil. It doesn't care. If your system actually built sludge from the mixture, whoever did it really screwed it up. I've torn apart many incorrectly converted systems and rarely saw that. Most of the contaminated system's that took out compressors and TXV's were done by water forming acid's. The system absorbs moisture through the aluminum. This is why you have a drier in the system. Water builds up and forms acids. The drier should be periodically changed. 10 odd years at least if the system wasn't opened for a while.
When you tear down the system, look at the color of the oil. Water contamination makes the oil a brownish. When you do your final vacuum, make sure the system is close to or over 80 degrees. The average good automotive vacuum pump pulls around 28 in of vacuum. That brings the water boiling point between 70 and 80 degrees. If its too cold you wont boil out the water no matter how long you leave the pump on.
When you tear down the system, look at the color of the oil. Water contamination makes the oil a brownish. When you do your final vacuum, make sure the system is close to or over 80 degrees. The average good automotive vacuum pump pulls around 28 in of vacuum. That brings the water boiling point between 70 and 80 degrees. If its too cold you wont boil out the water no matter how long you leave the pump on.
Just get your EPA license for restricted refrigerants. It's cheap and easy. I bought R12 on eBay for my '91. All I had to do was provide my valid EPA license number.
smritte
SILVER Star
I've been dealing with refrigerants for decades. I have my 608 and all the 609, is that what you mean? I have never heard of a restricted refrigerant license. Do you have a link? I couldn't find any reference at all.
Looking for R-12, the only place I found it was on sale at refrigerant depo at $3750 for a 20 pound can. Do you have a better price there also?
Last edited:
I see R12 on Facebook Marketplace all the time. Just people cleaning out their garage.
I was talking about the 609 license. Sorry, it's been a while since I looked at it. When I got it, it cost like $25 and was an open book test. I just found a can of R12 on eBay, but it was $75 for a 12 ounce can. Just like everything else, I suppose prices have gone up. Looks like they have an "EnviroSafe" R12 substitute available for cheaper. Don't know how well it might work since I never used it. All I know is that I got the 609 license to purchase R12 off eBay and my '91 blows ice cold because of it. Sounds like everything nowadays is more expensive and difficult to do. I apologize if my post gave you incorrect or outdated information.
There is also the hydrocarbon based refrigerants. I used 12 Oz of Duracool 12a and have been very happy with it. This on a 1991 import that was converted to 134 but had issues. @mrlocksmith has a great post about these refrigerants.
most of those "r12 substitute" cans are just propane. It has to say that it actually is real R12 To get the same performance and not be flammable.
real r12 is actually about the same price as yf1234 for me napa still has it in 20lb if you have your paperwork. But do you really want to go shooting some r12 into your old system? It's probably just going to leak back out. the cruiser has one of the most accessible and easy to work on AC systems. May as well replace the 0-rings. blow all the old oil out, take a close inspection and replace the drier (cheap). then convert it to 134a.
real r12 is actually about the same price as yf1234 for me napa still has it in 20lb if you have your paperwork. But do you really want to go shooting some r12 into your old system? It's probably just going to leak back out. the cruiser has one of the most accessible and easy to work on AC systems. May as well replace the 0-rings. blow all the old oil out, take a close inspection and replace the drier (cheap). then convert it to 134a.
I was after the better performance from my AC. 12a provides better cooling for a R12 system that was retrofitted to R134a. Yes it is a mix of propane and isobutane and is flammable but you end up using very little of it. I used 12 Oz. It is also compatible with the oil in the system from R12.
r12 is better on paper and maybe in AZ it is worth the trouble. The 80 series is one of the best to convert since all the components are also made in the r134a configuration from the factory also.
