Benefits Of R12
09-07-23, 08:13 PM
#1
10th Gear
Thread Starter
Benefits Of R12
Hello, this is one of my first post on the forums so I thought why not make it general for everyone to comment and put in their 2 cents.
Here's the story. I have a 1993 Lexus SC400 with no ac. The previous owner said it needed more freon, so I got a technician to come look at it.
He said it used R12. So I dug around some forums and found out that R12 has been banned in California for about 30 years now!
So I would like to know some of the benefits of keeping R12 refrigerant and basically getting it refilled in Arizona or something like that.
Cause I heard somewhere on YotaTech forums that all the new refrigerants leak out the hoses and doesn't get as "cool" as the R12.
Don't worry about me passing smog (I know a guy)
Here's the story. I have a 1993 Lexus SC400 with no ac. The previous owner said it needed more freon, so I got a technician to come look at it.
He said it used R12. So I dug around some forums and found out that R12 has been banned in California for about 30 years now!
So I would like to know some of the benefits of keeping R12 refrigerant and basically getting it refilled in Arizona or something like that.
Cause I heard somewhere on YotaTech forums that all the new refrigerants leak out the hoses and doesn't get as "cool" as the R12.
Don't worry about me passing smog (I know a guy)
09-07-23, 08:25 PM
#2
Lexus Champion
R12 is more effective than 134a in terms of carrying heat, if you fill with 134a you need to fully purge the old oil since it is not soluble in 134a and is needed for the compressor to work. Then the hard part is filling the system enough for the 134a to work as well as possible without overfilling since if you follow the fill for R12 it will be weak, some cars should/need to have the expansion device changed as well. Always change the accumulator.
09-07-23, 08:31 PM
#3
Lexus Test Driver
I worked a lot with R12 back in the day right out of high school.
It's far superior about ice cold temps fast.
I hope you can still get R12.
Not sure what a R134a conversion would require but the pressures are different and may require updating the compressor for R134a to get cool temps, plus other stuff like mentioned above, plus, plus.
PS- Welcome to Club Lexus and your first Post!
It's far superior about ice cold temps fast.
I hope you can still get R12.
Not sure what a R134a conversion would require but the pressures are different and may require updating the compressor for R134a to get cool temps, plus other stuff like mentioned above, plus, plus.
PS- Welcome to Club Lexus and your first Post!
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MichaelsCreations (09-08-23)
09-07-23, 08:35 PM
#4
Lexus Fanatic
I have a car that was converted to 134 I estimate cooling loss of about 20%.
09-07-23, 08:58 PM
#5
Lexus Fanatic
Welcome to CL and your first post, MichaelsCreations. 
There are conversion-kits available for many older cars from R12 to R134. My experience with newer R-134 vehicles, even in D.C.'s hot humid summers, is that there is little if any difference between the cooling-performance of the two. And, Lexus, like GM, has a reputation for good A/C systems.
There are conversion-kits available for many older cars from R12 to R134. My experience with newer R-134 vehicles, even in D.C.'s hot humid summers, is that there is little if any difference between the cooling-performance of the two. And, Lexus, like GM, has a reputation for good A/C systems.
The following 2 users liked this post by mmarshall:
KahnBB6 (09-08-23),
MichaelsCreations (09-08-23)
09-08-23, 08:52 AM
#6
My SC is still R12, and my 07 Tundra and 02 Celica have the R134. The SC freezes me out of the car. I leave a sweater in there because at certain points and times I start developing a cough. Don't have that with either Tundra nor Celica. The Celica is more efficient than my Tundra as it cools the whole cabin, my Tundra only cools the front seats, if you call it cool. For reference our summers here are deep in the Hundos... 105+ in the Summer.
09-08-23, 10:15 PM
#7
My '93 SC300 was an original R12 car. From old dealer service records the original owner had it converted over to R134a *at* the dealer sometime in the late 90's or early 2000's so I never got to experience it in my SC. I had an old R12 system in a classic Ford a long time ago but that wasn't comparable being an under-dash add-on kit to a factory non-A/C car (ie: it wasn't very efficient).
The A/C with R134a has always blown strong and cold for me in both southern California and Florida. Turbocharged SC's might do well with either the factory Soarer condenser fan or an aftermarket one since there is far more under-hood head generated and heat soak can happen. You shouldn't need that with any naturally aspirated stock SC but with the current hot average temperatures an auxiliary cooling fan on on the condenser triggered by either the A/C mag clutch relay kicking on or triggered via a relay with a coolant temperature switch could help. But those are extreme solutions that really should only be needed for turbocharged SC's.
Also I found that a combination of Llumar Air Blue windshield film and Llumar CTX side and rear window film do help a bit to keep my SC interior temperatures a little cooler in the summer months.
Toyota and Denso should still sell the o-ring and oil conversion kit. All the original A/C components that were designd for R12 work with R134a. I'd leave the work to a professional but in short no there isn't any advantage to hunting down expensive and increasingly rare R12 refrigerant that has been banned in CA. R134a will work just fine after the system has been purged with all new O-rings throughout and new oil. Also don't forget to install a new receiver-drier at the same time.
The A/C with R134a has always blown strong and cold for me in both southern California and Florida. Turbocharged SC's might do well with either the factory Soarer condenser fan or an aftermarket one since there is far more under-hood head generated and heat soak can happen. You shouldn't need that with any naturally aspirated stock SC but with the current hot average temperatures an auxiliary cooling fan on on the condenser triggered by either the A/C mag clutch relay kicking on or triggered via a relay with a coolant temperature switch could help. But those are extreme solutions that really should only be needed for turbocharged SC's.
Also I found that a combination of Llumar Air Blue windshield film and Llumar CTX side and rear window film do help a bit to keep my SC interior temperatures a little cooler in the summer months.
Toyota and Denso should still sell the o-ring and oil conversion kit. All the original A/C components that were designd for R12 work with R134a. I'd leave the work to a professional but in short no there isn't any advantage to hunting down expensive and increasingly rare R12 refrigerant that has been banned in CA. R134a will work just fine after the system has been purged with all new O-rings throughout and new oil. Also don't forget to install a new receiver-drier at the same time.
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RXRodger (09-22-23)
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