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07-21-2010, 03:01 PM
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Switching from R-12 to R-134a?
How much should it cost? Everything works, but it's showing signs of being slightly low on Freon. New o-rings, new fittings, new dryer and R-134a? Could someone give me a ballpark price range, please?
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07-21-2010, 04:09 PM
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truckemup97,
Are you sure you have to do all of that? I thought that you could just add the R-134a to the system and that it would mix with the freon. I might be wrong, but I remember hearing that somewhere.
Peace,
gordon
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07-21-2010, 04:24 PM
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There is a direct replacement for your R-12.I cant recall the name at this time but its in my fathers car and works fine.I no one knows what it is I'll give him a call a little later,He'll know.
Find a mechanic with a leak detector before it runs dry and fix that first.Then vacuum it down add oil and charge.Replacing the drier is a good idea at this time also.
Find out if its worth reparing or just feeding it once in a while.Some cars the evaporator is a bear to get to and the whole dash has to be removed to gain access.
DG
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07-21-2010, 04:38 PM
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Gordon,R-12 and 134R are incompatable and the oil in the compressor is also.I've seen mechanics not change all of the O-rings because of the time and effort,some times they get away with it because they don't care and don't plan on staying at that shop for long.One or two weasels in a shop make it real tough for the good guys with all of the time spent on fixing comebacks.I worked for a shop and told the owner that I knew the guy he was about to hire,"He's a hack"I told him and he still hired him.When I found out I told the boss that I wouldn't touch anything that he worked on.A few months later said Hack was gone and I ate my words.I got so much unpaid for jobs that I quit and found another shop.
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07-21-2010, 04:47 PM
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Do not mix R12 and R134a, they are incompatable. Besides o-rings you'll also need a new expansion valve with a larger orafice for the 134. The system will need to be completely flushed because the PAG oil and Ester oil used in the respective systems are also incompatable.
Forgot to add: Stay away from the so called "direct replacement" for R12, I believe it is called Freeze12. It may be compatable but it is propane based, not the sort of thing you want possibly leaking into the vehicle cabin were it could be exposed to open sources of ignition.
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07-21-2010, 04:57 PM
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Just to make you feel better, I've converted three systems, and none of them worked for long. The 134 runs at a higher pressure, and the old compressors just could not take it.
Around $800 to do everything right so you can just run it and not have to keep fiddling with it.
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07-21-2010, 05:10 PM
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I had an ex-brother in law that lived in Texas that just went across the border and filled his up with the "real McCoy," but I wouldn't recommend it.
Heck, you can still buy original cans of R12 on ebay...it's just a bit more expensive, but it works and it's the "real thing."
Looks like about $20 to $35 a can, and not too bad. However, you might can find an air conditioning shop around that will just recharge it with real R-12.
I am not about to change the system on my old '73 LTD- coldest air in town.
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Last edited by Andy Griffith; 07-21-2010 at 05:12 PM.
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07-21-2010, 05:17 PM
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Quote:
Originally Posted by Andy Griffith
I am not about to change the system on my old '73 LTD- coldest air in town.
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This one is ice cold, too, on the highway. Around town, though, in stop and go driving, not so much. Well, if I bought a $3500 car for $1850, I guess I've got some wiggle room to fix the A/C.
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07-21-2010, 05:29 PM
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If the leak is really small, I would stick with the R-12. You can still
buy it in some places, even e-bay, but you will need an EPA cert,
which you can take open book, maybe even online. It's a really simple
test. Like OKFC05 says, you'll run higher head pressures with the 134a,
and the usual method is to slightly undercharge the system to avoid
the excess pressure. This is due to the R-12 condenser coil being
undersized for 134a use. And as mentioned, the two are not compatible,
and you will need a flush and maybe more to convert over.
That will almost surely cost you more than just topping off the R-12..
And the R-12 will work much better being as the system was designed
around it.
A system designed for 134a does not have these problems as the
condenser coil is properly sized, and the system is designed for the
different refrigerant.
This is now an issue on home systems, being as you can no longer
buy new units that use R-22. They are all 410a now. Which is most
definitely not compatible, and runs at much higher pressures.
Too bad I ain't close to Tulsa.. I have R-12 running out my kazoo, and
I almost never use it.. I have a full 30 pound jug of it, and it just
collects dust... :/
I'd top you off for free if you were close.. Probably wouldn't take more
than a pound or so..
I do go to OK every once in a while, but still not exactly close to
where you are.. My place is near Eufaula, and still about 85 miles
south of Tulsa.. " I think that is where you are, if I remember right."
Anyway, if it were mine and the leak is slow, I'd stick with R-12.
The price of R-12 has actually fallen a bit I think, compared to a while
back when it was like liquid gold.. I think the demand is falling off.
It's still not cheap, but like I say, it will almost surely be cheaper
than all the work of converting. And the converted system will never
work quite as well.
Now R-22 is slowly becoming the new liquid gold.. :/
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07-21-2010, 05:48 PM
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Performance is all over the place with conversions, cars and trucks designed with the new freon have much larger condensors and better grade of hose because the molecules are smaller. Some waterpump driven fans need to be changed to pull more air through the condensor. Fix the leak and stay with R12 if possible.
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07-21-2010, 06:38 PM
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Stick with R-12 if possible-colder!Changing over is expensive also.Use real R-12 .
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07-21-2010, 06:50 PM
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I remember R12 for less than a buck a pound back in the day. I agree with those who say keep the R12 if you can. Had to convert my '80 Vette to 134a a few years back, too many leaks from rusted components. 134a is nowhere near as cold as R12.
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07-23-2010, 05:16 PM
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I had a friend make the change over today. It cost her 71.00 for the kit and labor. It is working good now but who knows how long. I have had reports from other friends who have had good luck with the change over.
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07-23-2010, 09:48 PM
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freeze 12.........google it
I've used in an 18YO honda with very good results,
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07-23-2010, 10:13 PM
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What year, make, model of car? How many miles on it?
Conversions are not that costly. R134A isnt very expensive and works well in most old R12 systems...with the exception of some older Fords and a few Chryslers.
The drier/accumulator must be changed, the system flushed(to remove as much of the old oil as possible), the proper amount of either PAG or Ester oil added and the system Charged with R134. The system should be charged with 75% of the R12 charge and then adjusted to achieve best performance BUT the R134A charge MUST NOT exceed 90% of the R12 charge. The metering device usually does not have to be changed nor do the orings or hoses.
PM me if you want more detail.
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07-24-2010, 10:01 AM
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Freeze 12..direct replacement for the old R12.
If you do convert, you really should replace the compressor, dryer, orfice tube(or hose), flush the system, and use either ester oil or pag.
parts, labor and all could cost well over a $1000.
In a R12 system converted to 134A, you need to use approx 80% of the original refrigerant volume. Meaning less 134A than the R12 volume. Freeze 12 is the same....use less.
In some vehicles Freeze 12 may work better than 134A. Gives lower high side pressures, and may cool better.
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