AC conversion R12 to 134a
07-20-07, 11:06 AM
#31
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If the R12 guy that I found does not work out tomorrow, I'm definitely going to JPI for the conversion. The humidity combined with the heat have been terrible since it has stopped raining 
07-20-07, 11:41 AM
#32
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07-20-07, 07:19 PM
#34
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No, he's a totally legit tech. Owns a biz that services vehicles much older than any of ours. I haven't asked him if he wants to have his info given out, but I will tomorrow. I also want to make sure that I do not violate any rules or step on any toes. 
07-20-07, 11:05 PM
#35
Lexus Test Driver
Another option is R406A if your system is still R12-- it's a direct replacement and will work with the existing refrigerant as well as the existing mineral oil--
IF your system is an R134A system from the factory, THE FITTINGS WILL NOT UNSCREW and are PART OF THE LINE-- !!!
-- just thought I'd throw that one in--
This is what R134A fittings look like-- they're a quick release style instead of threaded like R12 fittings-- if your fittings have threads on the outside, the system is still R12 --
IF your system is an R134A system from the factory, THE FITTINGS WILL NOT UNSCREW and are PART OF THE LINE-- !!!
-- just thought I'd throw that one in-- This is what R134A fittings look like-- they're a quick release style instead of threaded like R12 fittings-- if your fittings have threads on the outside, the system is still R12 --
07-23-07, 07:00 AM
#36
Driver School Candidate
Dude. This thread made me throw up a little in my mouth. I wasn't aware that they put such feeble hoses into our SC's that they will seep out R134A. 
I've had much older cars retrofitted to R134A in the past and they've worked fine. Don't just buy some cheap-*** eBay kit and expect it to work. You need to change the condenser and the oil in the compressor. Change the O-Rings as well.
mitsuguy has some of his info correct, but not all of it. I'm not sure what kind of shop he works at or the level of knowledge and experience of the people there, but the right tech can get the job done correctly without issue.
Take your car to a reputable shop and have them do the conversion. It will be money well spent.
I've had much older cars retrofitted to R134A in the past and they've worked fine. Don't just buy some cheap-*** eBay kit and expect it to work. You need to change the condenser and the oil in the compressor. Change the O-Rings as well.mitsuguy has some of his info correct, but not all of it. I'm not sure what kind of shop he works at or the level of knowledge and experience of the people there, but the right tech can get the job done correctly without issue.
Take your car to a reputable shop and have them do the conversion. It will be money well spent.
07-23-07, 07:11 AM
#37
Dude. This thread made me throw up a little in my mouth. I wasn't aware that they put such feeble hoses into our SC's that they will seep out R134A. I've had much older cars retrofitted to R134A in the past and they've worked fine. Don't just buy some cheap-*** eBay kit and expect it to work. You need to change the condenser and the oil in the compressor. Change the O-Rings as well.
mitsuguy has some of his info correct, but not all of it. I'm not sure what kind of shop he works at or the level of knowledge and experience of the people there, but the right tech can get the job done correctly without issue.
Take your car to a reputable shop and have them do the conversion. It will be money well spent.
I've had much older cars retrofitted to R134A in the past and they've worked fine. Don't just buy some cheap-*** eBay kit and expect it to work. You need to change the condenser and the oil in the compressor. Change the O-Rings as well.mitsuguy has some of his info correct, but not all of it. I'm not sure what kind of shop he works at or the level of knowledge and experience of the people there, but the right tech can get the job done correctly without issue.
Take your car to a reputable shop and have them do the conversion. It will be money well spent.
Again, to me, putting HCF134a in a R12 system is like putting 87 octane in a car designed for 91 - sure it works, just not up to its full potential...
Also, have you ever taken a refrigerant sniffer to one of those old hoses that you claim don't seep 134? I would bet money that they do - it's nothing you can see, hear or smell, so to many, there isn't an issue, but when a year goes by and all the 134 is gone, you'll know... (or you take a sniffer to it)
I guess my biggest point of confusion here is that if you are going to the expense of replacing a condenser to make the 134 work better, why not just stick with what it was designed for anyways...
Last edited by mitsuguy; 07-23-07 at 07:15 AM.
07-23-07, 08:11 AM
#38
Driver School Candidate
What have I said that is not correct? I have done A/C conversions. I never ever recommend it, and through our shop, we WILL NOT do it. They do work well in certain circumstances, but not in all, nor do they work great when really stressed. Unless you have experience in 115-120 degree temperatures, you can't say you've really put a cars cooling system (both engine cooling and a/c) through its paces... Here, even a mildly weak fan clutch will cause overheating and huge A/C issues...
Again, to me, putting HCF134a in a R12 system is like putting 87 octane in a car designed for 91 - sure it works, just not up to its full potential...
Also, have you ever taken a refrigerant sniffer to one of those old hoses that you claim don't seep 134? I would bet money that they do - it's nothing you can see, hear or smell, so to many, there isn't an issue, but when a year goes by and all the 134 is gone, you'll know... (or you take a sniffer to it)
I guess my biggest point of confusion here is that if you are going to the expense of replacing a condenser to make the 134 work better, why not just stick with what it was designed for anyways...
Again, to me, putting HCF134a in a R12 system is like putting 87 octane in a car designed for 91 - sure it works, just not up to its full potential...
Also, have you ever taken a refrigerant sniffer to one of those old hoses that you claim don't seep 134? I would bet money that they do - it's nothing you can see, hear or smell, so to many, there isn't an issue, but when a year goes by and all the 134 is gone, you'll know... (or you take a sniffer to it)
I guess my biggest point of confusion here is that if you are going to the expense of replacing a condenser to make the 134 work better, why not just stick with what it was designed for anyways...
While I haven't lived in a climate with 115 degree temperature, I have visited Vegas, Palm Springs and other desert climates where it gets that hot during the summer. The 134 that I retrofitted my car with held for 3 years until I sold it. There was a leak shortly after conversion, but that was a pinched O-Ring. I would be pretty upset to find that inferior hoses were used in my Lexus.
The reason to convert to 134 vs throwing money away at a deprecated system is that when you have to fix it again (And you will regardless of what refrigerant you use), you'll already be up to the current spec. If it's the same cost to convert, then you're just throwing money away at charging the system. If you have to charge the system, then you have a leak somewhere. With all the labor involved with fixing your old, out of date, AC system, you are probably better off converting. Just do it the right way.
07-23-07, 08:44 AM
#39
I don't buy for a second that the 134 seeps out of the hoses.
While I haven't lived in a climate with 115 degree temperature, I have visited Vegas, Palm Springs and other desert climates where it gets that hot during the summer. The 134 that I retrofitted my car with held for 3 years until I sold it. There was a leak shortly after conversion, but that was a pinched O-Ring. I would be pretty upset to find that inferior hoses were used in my Lexus.
The reason to convert to 134 vs throwing money away at a deprecated system is that when you have to fix it again (And you will regardless of what refrigerant you use), you'll already be up to the current spec. If it's the same cost to convert, then you're just throwing money away at charging the system. If you have to charge the system, then you have a leak somewhere. With all the labor involved with fixing your old, out of date, AC system, you are probably better off converting. Just do it the right way.
While I haven't lived in a climate with 115 degree temperature, I have visited Vegas, Palm Springs and other desert climates where it gets that hot during the summer. The 134 that I retrofitted my car with held for 3 years until I sold it. There was a leak shortly after conversion, but that was a pinched O-Ring. I would be pretty upset to find that inferior hoses were used in my Lexus.
The reason to convert to 134 vs throwing money away at a deprecated system is that when you have to fix it again (And you will regardless of what refrigerant you use), you'll already be up to the current spec. If it's the same cost to convert, then you're just throwing money away at charging the system. If you have to charge the system, then you have a leak somewhere. With all the labor involved with fixing your old, out of date, AC system, you are probably better off converting. Just do it the right way.
A great summary of what it really takes to convert... (and it has information on barrier hoses) Keep in mind, the system was still designed for R12, and will still not work to 100% of its potential, but may be acceptable some places and in some cars... Las Vegas and desert climates, when you live here, and you actually go through the paces of getting into a car thats 160+ degrees and having it try to cool down, you are wanting that extra few percent of efficiency - I am actually building a water sprayer for the a/c condenser...
07-23-07, 10:48 AM
#40
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why is this even in the performance section? i troll through this site all day looking for ways to make my lexus badder than it already is and i find a a/c related question hogging valuable thread space.
that being said i'm shocked to find out that lexus uses hoses (on the older r12 models) that will "leak" out all the refrigerant in it. wouldn't this make them more likely to leak sooner even with the r12? i don't claim to be the high and mighty a/c guy but i have converted the air in my truck i use to haul my boat with and i can tell you it does not leak. i did it over 3 years ago and it's still blowing cold. i have put it under the "sniffer" and it shows no signs of going anywhere. are you telling me that General Motors put better parts on a work truck than lexus would put on a high end car? you can't tell me that they didn't know that r12 was going out and that sooner than later (i'm sure someone knows the exact year that they switched to r134) they would be some sort of retrofitting going on with these cars. i'm not going to tell people not to put r12 in their cars, if they want to spend more money, on something most people will never notice any sort of difference with, go for. i know what works for me i just feel bad for you people who own the older inferior cars.
thats my .02.
that being said i'm shocked to find out that lexus uses hoses (on the older r12 models) that will "leak" out all the refrigerant in it. wouldn't this make them more likely to leak sooner even with the r12? i don't claim to be the high and mighty a/c guy but i have converted the air in my truck i use to haul my boat with and i can tell you it does not leak. i did it over 3 years ago and it's still blowing cold. i have put it under the "sniffer" and it shows no signs of going anywhere. are you telling me that General Motors put better parts on a work truck than lexus would put on a high end car? you can't tell me that they didn't know that r12 was going out and that sooner than later (i'm sure someone knows the exact year that they switched to r134) they would be some sort of retrofitting going on with these cars. i'm not going to tell people not to put r12 in their cars, if they want to spend more money, on something most people will never notice any sort of difference with, go for. i know what works for me i just feel bad for you people who own the older inferior cars.
thats my .02.
07-23-07, 11:17 AM
#41
why is this even in the performance section? i troll through this site all day looking for ways to make my lexus badder than it already is and i find a a/c related question hogging valuable thread space.
that being said i'm shocked to find out that lexus uses hoses (on the older r12 models) that will "leak" out all the refrigerant in it. wouldn't this make them more likely to leak sooner even with the r12? i don't claim to be the high and mighty a/c guy but i have converted the air in my truck i use to haul my boat with and i can tell you it does not leak. i did it over 3 years ago and it's still blowing cold. i have put it under the "sniffer" and it shows no signs of going anywhere. are you telling me that General Motors put better parts on a work truck than lexus would put on a high end car? you can't tell me that they didn't know that r12 was going out and that sooner than later (i'm sure someone knows the exact year that they switched to r134) they would be some sort of retrofitting going on with these cars. i'm not going to tell people not to put r12 in their cars, if they want to spend more money, on something most people will never notice any sort of difference with, go for. i know what works for me i just feel bad for you people who own the older inferior cars.
thats my .02.
that being said i'm shocked to find out that lexus uses hoses (on the older r12 models) that will "leak" out all the refrigerant in it. wouldn't this make them more likely to leak sooner even with the r12? i don't claim to be the high and mighty a/c guy but i have converted the air in my truck i use to haul my boat with and i can tell you it does not leak. i did it over 3 years ago and it's still blowing cold. i have put it under the "sniffer" and it shows no signs of going anywhere. are you telling me that General Motors put better parts on a work truck than lexus would put on a high end car? you can't tell me that they didn't know that r12 was going out and that sooner than later (i'm sure someone knows the exact year that they switched to r134) they would be some sort of retrofitting going on with these cars. i'm not going to tell people not to put r12 in their cars, if they want to spend more money, on something most people will never notice any sort of difference with, go for. i know what works for me i just feel bad for you people who own the older inferior cars.
thats my .02.
It's not about better parts, it's about what works and what works correctly. How many times has that a/c compressor been replaced? The compressor in my car, with 185k miles and 14 years old is still original and still works 100%.
07-30-11, 01:33 PM
#42
Bumping this one from the dead. Does anyone know EXACTLY what is different between R12 and R134 systems? I want to convert mine fully to 134 with all applicable 134 specific parts. I am pretty sure the condenser, compressor, and txv are different, but do I have to buy all the hard lines as well, or will the newer stuff bolt up? Is the evap different between the different systems as well?
TIA
TIA
07-30-11, 01:42 PM
#43
Bumping this one from the dead. Does anyone know EXACTLY what is different between R12 and R134 systems? I want to convert mine fully to 134 with all applicable 134 specific parts. I am pretty sure the condenser, compressor, and txv are different, but do I have to buy all the hard lines as well, or will the newer stuff bolt up? Is the evap different between the different systems as well?
TIA
TIA
Usually to do a conversion, you can get away with replacing the receiver/drier, and adding new oil for the R134...
07-30-11, 02:05 PM
#44
Well, it has been converted, but I am not sure how long ago. I know its leaking at the high side fitting, but that may be a simple shrader valve fix. Who knows if it is leaking anywhere else at this point.
The car cools just ok when its below 90°, but once it get hotter out, the system just cant keep up. I have checked the charge with the cheapo, single gauge charging can, and charged it to about 52psi lowside at ~100° ambient.
I have had other "converted" setups, meaning fittings, oil, refrigerant. None of them ever did much once ambient gets to 100° or above
I know I can drain and flush the system as-is and then revert it back to R12, but I have yet to find a place in town that wants to touch it. Also, all these hoses, fittings, compressor, etc are approaching 20 years old.
I figure I can find a low mile late model and rob all the r134 stuff from it. I would get newer parts, and have a system engineered to work with r134. I imagine a system designed for 134 would cool great even into the 100°+ range. Am I pretty safe in this assumption?
The car cools just ok when its below 90°, but once it get hotter out, the system just cant keep up. I have checked the charge with the cheapo, single gauge charging can, and charged it to about 52psi lowside at ~100° ambient.
I have had other "converted" setups, meaning fittings, oil, refrigerant. None of them ever did much once ambient gets to 100° or above
I know I can drain and flush the system as-is and then revert it back to R12, but I have yet to find a place in town that wants to touch it. Also, all these hoses, fittings, compressor, etc are approaching 20 years old.
I figure I can find a low mile late model and rob all the r134 stuff from it. I would get newer parts, and have a system engineered to work with r134. I imagine a system designed for 134 would cool great even into the 100°+ range. Am I pretty safe in this assumption?
07-30-11, 02:19 PM
#45
Well, it has been converted, but I am not sure how long ago. I know its leaking at the high side fitting, but that may be a simple shrader valve fix. Who knows if it is leaking anywhere else at this point.
The car cools just ok when its below 90°, but once it get hotter out, the system just cant keep up. I have checked the charge with the cheapo, single gauge charging can, and charged it to about 52psi lowside at ~100° ambient.
I have had other "converted" setups, meaning fittings, oil, refrigerant. None of them ever did much once ambient gets to 100° or above
I know I can drain and flush the system as-is and then revert it back to R12, but I have yet to find a place in town that wants to touch it. Also, all these hoses, fittings, compressor, etc are approaching 20 years old.
I figure I can find a low mile late model and rob all the r134 stuff from it. I would get newer parts, and have a system engineered to work with r134. I imagine a system designed for 134 would cool great even into the 100°+ range. Am I pretty safe in this assumption?
The car cools just ok when its below 90°, but once it get hotter out, the system just cant keep up. I have checked the charge with the cheapo, single gauge charging can, and charged it to about 52psi lowside at ~100° ambient.
I have had other "converted" setups, meaning fittings, oil, refrigerant. None of them ever did much once ambient gets to 100° or above
I know I can drain and flush the system as-is and then revert it back to R12, but I have yet to find a place in town that wants to touch it. Also, all these hoses, fittings, compressor, etc are approaching 20 years old.
I figure I can find a low mile late model and rob all the r134 stuff from it. I would get newer parts, and have a system engineered to work with r134. I imagine a system designed for 134 would cool great even into the 100°+ range. Am I pretty safe in this assumption?
Harbor Freight sells a set of R134 manifold gauges for $50... if you plan on doing this yourself, they will save you some frustration...