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Switch back A/C from R134a to R14?

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luvmy82

Guest
I've recently discovered that the A/C in my 1982 CE is on the fritz. My mechanic is suggesting that I convert back to R14 to resolve the freon leak problem I'm experiencing.
We did trouble shoot, and the compressor is working fine, and the previous owner installed a new relay switch and it was working just fine last year, but when I tried to fire it up last week during the heat wave, I just got hot air and I have no freon left.

Now from what I understand, to charge with R14 costs an arm and a leg. Is this true? Would you convert your A/C back to R14 from R134a? Is this assesment true as to why the A/C is not working? Let me know your thoughts on this....I'd love to go back to my mechanic armed with some suggestions and helpful information.
 
C

c4ever

Guest
Why would you want to convert back to something that costs $$$$$$$$$$$:confused If the crossover was done correctly I would make the necessary repairs and move on. I'd have to question the mechanics motives here. I can't say what the problem is with the info provided, others can be more helpful there, but IMHO I'd stay with the R134a:w
 
L

luvmy82

Guest
Well I found out some further information. The reason why they would consider going back to R12 instead of R134a is the freon molecule size in R12 is larger. If the molecular structure of R12 freon is larger, then the leak would not happen the smaller the molecule size, the greater chance it has to leak.

I'm with you, I don't want to move backwards and have a freon charge run me the bucks every time I need it.
 

69MyWay

Well-known member
Joined
Jul 3, 2001
Messages
4,364
Location
Auburndale, Florida
Corvette
1969 Killer Shark
I think you mean R12, right? Anyway, you are not going to solve any leaks by switching back. In fact, R12 is so sensative to the oil, that any trace of the 134 oil in the system could spell disaster for the compressor.

If you are out of Freon, you simply have leak. This could be as simple as an o-ring seal, or as serious as the actualy evap in the firewall.

If you are not going to do this work yourself, I suggest you have a long sit down with the mechanic to figure out exactly what he is suggesting, or go find a new mechanic that will simply locate and repair the leak, the fill it back up with the same stuff that is in there now.
 

Jack

Well-known member
Joined
Dec 27, 2000
Messages
1,825
Location
Florence, SC (Timmonsville SC)
Corvette
71 War Bonnet Yellow VERT 71 BH Blue CPE (SOLD)
/c4ever ...Why would you want to convert back to something that costs $$$$$$$$$$$ If the crossover was done correctly I would make the necessary repairs and move on. I'd have to question the mechanics motives here. I can't say what the problem is with the info provided, others can be more helpful there, but IMHO I'd stay with the R134a

/Chris ...I think you mean R12, right? Anyway, you are not going to solve any leaks by switching back. In fact, R12 is so sensative to the oil, that any trace of the 134 oil in the system could spell disaster for the compressor.

DITTO... I'm with c4ever & Chris.
JACK:gap
 
L

luvmy82

Guest
Chris, I have a tennancy to think you are right. Going backwards to R12 (sorry, typed in the wrong #) is not the answer, and to just find out why the R134a is leaking and move forward from there. I'll let you know what he suggests and get back with you guys for further consultation! Thanks again!
 
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page62

Guest
Do you have an R134a compressor, or was the system simply converted without a compressor change. In order to do it the conversion right, a change is highly recommended.

PS: I stuck with R12 when I had my $ystem overhauled...
 
B

Big Fish

Guest
No reason why the 134A won't work. If it leaked out, so will the 12. A better choice yet is hot shot but it has not been DOT approved. Locate and repair the leak(s). Have you mechanic pull a deep vacuum and make sure it will hold between 500 and 600 microns with the pump blanked off for 15 minutes. This will assure a leak free and moisture free system. Unfortunately most mechanics don't have the equipment or knowledge to properly evacuate in this manner. good luck
 
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jsimpson

Guest
All replacement hoses are designed to handle R-134. Old hoses are so oil impreganated that they will NOT leak R134 any more than they would leak R-12. Only a NOS R-12 hose would have any chance of leaking R-134, and the leakdown would take a year. All of the fears that people had about R-134 conversions when the price of R-12 first skyrocketed have proven unfounded. If you're rich enough to buy R-12, feel free to do so, but there is no advantage.
 
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joevette57

Guest
There is no reason the change the compressor if there were no problems with it to begin with.
If converting to 134, you MUST flush the system clean if you ever want any professional shop to ever work on it again. They use two recovery systems, one for each freon type and can't afford to contaminate either. They have a tester to determine if your system is contaminated.
After flushing system you MUST change the drier. IF you want optimum performance from 134A, you SHOULD change the condensor (in front of the radiator). 134A condensors have thinner, more numerous fins for better efficiency. But the system will work with the old condensor.
One thing that's important, All hose connection should be the new style crimp type. (Most c-3's have these). Using the 'ol hose clamp will not work (midyears). 134A will leak though those connections.
Stay with the 134A even you if you have a slight leak, $4.27 a can (Walmart) is a far cry from $25. (The going rate for a can of R-12 if you can find it.
 
J

jsimpson

Guest
As for efficiency, my R134 filled 78 is as cold as any new car in heavy hot Miami traffic. The real problem with old Vette air is poorly insulated cars and low blower velocity, both of which are relatively simple to address.
 
Joined
Aug 29, 2001
Messages
3,235
Location
Norcross, Georgia, United Stat
Corvette
2017 Arctic White Grand Sport
I'm getting ready to work on my a/c, or should I say, have my a/c worked on, and was quite surprised to find out that it appears to be cheaper to convert the system to r134 than fill it. He quoted me just over 2 pounds at about $150 per pound to fill the system. It will require a full charge because the system has to be evacuated and pressure tested for leaks (I know there is at least one). Assuming the compressor is ok, and it appears to be, he claims that he can convert it over for less than this.

Does this sound right?

Bob
 
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joevette57

Guest
Bob,
He's trying to hose you. The going rate for R-12 is about $40 per pound. A completely empty system can take up to 3 # to charge so $150 for the recharge would be more accurate.
Having said that, I would still convert it if the system's empty anyway.
 
7

78SilvAnniv

Guest
AC

I had my system switched to 134a to the tune of $1330.00 using a professional AC only repair shop. (I supplied the compressor and another big $ part, can't remember what) Highly impressed with their service; Polar Bear Auto & Truck Air in Sacramento, CA.

I also agree, if you have a leak now, and don't repair it, you still have a leak.
Silver
 
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page62

Guest
Bob, it's time to go shopping for another mechanic! In my case, it was about the same price to stay with R12 or switch to R134 (close to $1000). But despite the fact that I used a "gold-plated" A/C repair shop, they only charged $60/lb. for R12.

And when the R12 all blew out into the atmosphere a few weeks later (sorry, ozone layer), they fixed the problem and replaced the freon at no charge!
 
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jsimpson

Guest
$1330 sounds like a good price for a complete AC installation in a non-AC car, but extraordinarily high for a R134 conversion.
 
Joined
Aug 29, 2001
Messages
3,235
Location
Norcross, Georgia, United Stat
Corvette
2017 Arctic White Grand Sport
On the way home today I am going to stop at a shop that replaced the compressor on my 240-SX 6 or 7 years ago and get some idea of what they feel is involved.

I have gotten another quote on R12 at $65 per pound. I may have misunderstood my regular guy and he may have meant it will take a $150 charge rather than $150 per pound. He has been doing a good job on my mechanical stuff but air conditioning is so specialized that I am a little concerned about not going with a specialty shop.

I'm still leaning toward the conversion if the conversion price is as low as I was quoted, $400 - 500 if a compressor is not involved, as high as $1,100 if everything needs to be changed. I need to look into it further based on the price that Silver quoted, though I don't know how long ago hers was done, and have heard that the price has come down over the years on the conversion as people have become more knowledgable about what is involved.

Bob
 
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jsimpson

Guest
Mine was less than $300 by professional shop. He replaced the drier, a bad hose, and added an adjustable low pressure cutoff switch, pumped it out and filled with oil and R134. A reputable shop will credit you for the value of the R12 that they salvage, but mine was empty. It's been blowing cold in South Florida now for four years. I spent another hundred a year later to replace the blower motor and squirrel cage with the latest GM replacement, after testing a bunch of different blowers for air volume. Follow most of the advice in "Air Conditioning Strategies for the 63-82 Corvette", by Michael J. Davis, and you can't go wrong.
 

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