R-12 air conditioning/recharge or convert?
I recently purchased an all-original 78 pace car with 35 miles (yes, it's a 4-speed). The original owner purchased the car, took it home and put it up on blocks for 30 years. I'm not talented enough to do much work on the car, but have a guy that I trust (he restored 2 cars that received Bloomington Gold awards this year). After removing some oxidation and changing fluids, the car is in great shape. It's now time to work on the air conditioning. All the parts appear to be functioning, just no cold air. My guy would like to convert the car to R-134a. I'm leaning toward keeping the car original with the R-12. I would appreciate any advise on the pros and cons (other than the obvious cost) for keeping the R-12. I have no immediate plans to have the car judged, but that may change in the future. Thanks for your help. Chris.
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Re: R-12 air conditioning/recharge or convert?
Chris-----
I would NOT recommend converting the car to R-134a. It's just not worth the potential problems which can be created. However, I would want to ensure that all of the refrigerant-related seals are in perfect condition before doing any recharge, at all. If they are you'll probably never have to do another recharge.In Appreciation of John Hinckley -
Re: R-12 air conditioning/recharge or convert?
I'm with Joe on this one. I just went through this with my 69 with original AC. The recharge with R12 is the way to go. There's enough people around that can help you with this. System vac, pressure test, replace seals if necessary, and recharge. I've also heard a less expensive alternative called "Freeze 12" that was, or is, an alternative to R12.Comment
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Re: R-12 air conditioning/recharge or convert?
Stay with the R-12 , BTW do you need some?
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Re: R-12 air conditioning/recharge or convert?
None of the "drop in replacements" are quite as effective as r-12, but I've used both Freeze-12 and Envirosafe ES-12a with good results. They are readily available without having a license to buy them and cheap enough that if you only have a slow leak, you'd have to buy an awful lot of cans to equal what it would cost to rebuild a compressor or replace a poa valve. And it seems to me that both work considerably better than switching to r-134.Comment
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Re: R-12 air conditioning/recharge or convert?
I have two R-12 cars. Back when I went to the SEMA show in the nineties I always asked the servicing equipment providers what they recommended. The ALL said, keep the systems R-12 as long as R-12 is available. There are various techinical reasons why R-12 works better on systems that were originally designed for it. R-134a conversions don't provide as much cooling, and not all conversions are done properly, like properly purging the old oil and some cars need major new components, like condensers, to get adequate cooling performance.
It makes even more sense today because the price of R-12 is coming down and R-134a is going up. On a recent R-12 service the price of R-12 was $48/pound versus $28/pound for R-134a, and there is still plenty of R-12 around. Circa 2001 I paid 60 bucks a pound for an R-12 A/C service.
The biggest problem can be finding A/C shops that still service R-12 due to lack of demand since so many R-12 systems have been converted or the owners don't want to spend the money to keep old A/C systems running.
If you live is Southern California, Lynn's A/C in Lynnwood is a good shop that still services R-12 and they have a lot of vintage car customers.
DukeComment
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Re: R-12 air conditioning/recharge or convert?
I have also used the Envirosafe products with great results. It's inexpensive, cools well and is not a danger to the environment since it is not a cfc. Be aware, though, that the Envirosafe and some other drop in replacements may work well but are propane based which many feel is a highly dangerous (explosive?) alternative. Many people feel that a catastrophic failure could lead to a fire where the same failure in R-12 would not. I am confident enough that this is a remote possibility that I continue to use it.
JeffComment
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Re: R-12 air conditioning/recharge or convert?
Chris:
Stay with R12. Fix any leaks, and replace the drier. Pull a deep vacuum before charging to remove any residual moisture.
With some careful shopping, the price of R12 is around $15-20 per pound. This is just the refrigerant price....assuming you charge it yourself. R134a is around $5 per pound. System takes 3 pounds, so the initial cost difference can be as low as $40-50, if you do your own work. As Duke mentioned, price has come down quite a bit in the last few years.
The difference will be more if you have someone else service the AC, but it still is reasonable/affordable. The biggest problem comes if you can't get the system leak free and are constantly adding refrigerant. Take your time and find/fix the leaks before charging.
I recently read that the auto manufacturers were planning to replace 134a with another (more environmentally friendly) refrigerant within a few years. The two that are currently being evaluated are HFC-152a and HFO-1234yf.
LarryComment
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Re: R-12 air conditioning/recharge or convert?
I'm a big believer in R134a. Converted an Audi years ago, and it worked great. The biggest reason I like R134a is that you can buy it yourself (inexpensively) and refill your system yourself. With an older car, there are usually small leaks that you don't choose to fix because of he work and expense involved. With cheap and easy to refill refrigerant, it's easy to postpone a repair and throw a couple cans in to get the A/C working, at least for a while. I suspect that the problems people have with R134a is under or over filling.
But I feel you should keep your R12 system. You don't need to convert. Your system is new. Shouldn't be any hard to fix leaks in your system. Change the "O" rings and the dryer; draw as much vacuum for as long as you can; and, refill with R12. R12's a lot cheaper now too.
(BTW, look at the ingredients in the R12 replacement refrigerants. It's mostly R134a.)Comment
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Re: R-12 air conditioning/recharge or convert?
I vote with some of the other posters to keep your 78 using R12. The system can be just low on R12 and not cooling.
My 85 Corvette's air conditioning system was serviced in 92. It was cooling but I was going on a long trip and since I had recently acquired the car I just wanted to make sure all was okay.
The shop let me watch. Their machine removed the R12, the oil, and then put the vacuum pull. Then measured amount of oil and R12 was installed.
I did not notice any significant improvement after the service, but knowing it had the appropiate R12 was good to know. In 92 this service was a reasonable cost. The machine that was connected to my system did it all.
Shops that will only convert to R134 most likely do not have the equipment to service the R12 systems. My Chevrolet dealer does not.
This April is the first year I noticed my 85 having a lack of cooling. Having acquired guages and R12 years ago I installed some and it is cooling again. I do not know how low it was or how much R12 I put in. I put my 30# can of R12 on a decent bathroom scale but it did not registar any difference that I could make out.
No sight glass like on my 70 to view the R12 level. The 85's service manual references a feel method for adding R12 and that is what I used.
If your system is evacuated, you may loose some valuable R12. In years past when my 70 was low on R12 I could usually just put in about 1/2 can of R12 and clear up the sight glass.
If your system is only low on R12, a full can of R12 could help a lot.Comment
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Re: R-12 air conditioning/recharge or convert?
I converted my 71 over and it worked ok...for about two months, wished I would have just left it alone.Comment
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Re: R-12 air conditioning/recharge or convert?
Jim
Intriguing thread here. I recall we had a similiar about a year ago but tell us how you acquired the gauges, what it might cost us and if there is much "technical expertise" required to do this ourselves. I've got two 78's both that need work and I've dragged my feet really not wanting to do a conversion. I've convinced after this...no need to.Tom Russo
78 SA NCRS 5 Star Bowtie78 Pace Car L82 M2100 MY/TR/ConvComment
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Re: R-12 air conditioning/recharge or convert?
Tom:
The guages are available from any AC supply house. Google "r-12 guages". Robinair and Mastercool manifold sets can be bought for less than $100. I haven't charged a system with R-12 guages (I always used the "feel" method), but the only difference from R-134a should be the readings on the guages. The technique should be the same.
PaulComment
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Re: R-12 air conditioning/recharge or convert?
Regards
KennyComment
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Re: R-12 air conditioning/recharge or convert?
With any refrigerant, there is a pressure/temperature relationship. If you are adding less then a full charge, you need to use this relationship, along with ambient temperature and the feel of the suction & discharge line (temperature actually). You need to be carefull, since the discharge line can be extremely hot. You can obtain pressure/temperature charts on line through a Google search for the refrigerant in question.
Some of the new refigerants are blends and refrigerant shouldn't be added to them. Existing refrigerant needs to be reclaimed, the system leak checked, evacuated and then the proper charge measured in.
Most auto shops will reclaim the existing charge (in the old days they just dumped the charge), because they don't know how to determine a full charge, unless they are weighing it in.
DennisComment
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