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Converting Freon (R-12) Based A/C To R-34 On Older Vehicles

vmanvman Member Posts: 103
edited April 2014 in Ford
I had the opportunity to do this on my 86 Bronco (have had since 1/98). It's a good idea. The conversion was not as costly as I thought it would be. The kit contains a new evaporator, R-134 fittings, O-rings, and compressor oil. I've probably forgotten something, but the kits can be had through JC Whitney if nowhere else. The biggest part is evacuating the old system (you'll probably need a professional for this). After that, a quick compressor oil change, put the new parts on and you're ready for the new, cheap, and plentiful R-134 refrigerant. You also get the added benefit of environmental friendliness. It also works just as good if not better than R-12.


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    umflumfl Member Posts: 1
    A recent article in Mopar Collectors Guide discussed an alternative to freon that doesn't require changing the seals and compressor as is required for R-134A. It hasn't received EPA approval for use in automobiles yet, however it is considered acceptable as an industrial refrigerant. Look for this stuff to begin showing up at the car shows/swap meets this yea.
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    mminerbimminerbi Member Posts: 88
    To UMFl's point, I hope the new refrigerant to which you refer will be approved by the EPA. Until then I wouldn't take a chance.

    What is the refrigerant mentioned in the Mope article called?
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    oldjunkloveroldjunklover Member Posts: 7
    Where do you get "recycled and preexisting supplies of freon"? Don't you have to have a license to buy it? About 2 (or maybe 3) years ago, the auto chains around Oklahoma City pretty much quit selling freon 12 to anyone without a license.
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    greencargreencar Member Posts: 11
    in regards to the freon problem-conversion is very simple. most large auto parts stores carry conversion kits that are really simple to install.the current system must be in good shape.
    old hoses and driers-etc. need to be replaced.you need to drain as much old oil from the compressor-and then add the new style. remember-discharging freon into the atmosphere is a federal crime-jail time plus a huge fine-so watch your work area-if your not to mechanical-take it to a ac shop.you can still purchase freon-but the price runs $30-40 per 1lb can-i lucked out and got a case in Arizona for nothing-the guy wanted to get rid of it.this was better than winning the lottery.
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    mminerbimminerbi Member Posts: 88
    To Oldjunklover,

    Yes, you have to buy freon from a garage or dealer now because it's not sold through the auto stores anymore. The reason is that the garages and dealers who carry freon also have to have certain EPA approved equipment to install it, I believe. The reason for all this is so the freon won't escape into the atmosphere.

    As was stated in an earlier messager, you wouldn't want to convert to the newer R-34 unless a major component of your A/C goes, such as a compressor. That's happened to me with my '86 Pontiac Grand Am, but since it's an extra car in the family, I haven't bothered to invest the money for the conversion.
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    oldjunkloveroldjunklover Member Posts: 7
    There's a fascinating web site at


    regarding converting to 134a. There's also several links at that site to other information regarding auto air conditioning.

    Of particular interest to me is:
    -Use of "duracool" is not allowed.
    -Use of commonly used industrial refrigerants (butane and propane) is illegal.
    -Breaking a new compressor in with R-12 prior to conversion to R-134a is GOOD. Actually makes the compressor last longer.

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    isellhondasisellhondas Member Posts: 20,342
    In order to quickly cool down a choke to recreate a cold start problem, we would shoot a cloud of R-12 directly on the choke housing.

    We didn't know any better at the time.

    I am one of those who thinks the new R-134 does not cool as well as the old stuff.

    Oh, well, we have to do what is right, I guess...
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    guitarzanguitarzan Member Posts: 873
    Isell, considering the EPA has dictated the new refrigerant, my initial guess would be that R-12 was superior in every way.
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    prophet2prophet2 Member Posts: 372
    Had it done last year and I agree that the R-134 doesn't seem to cool down as quickly as the old stuff; doesn't seem to be as efficient. And my windows and back glass are tinted (after-market). As Isell says, though, we should do the "right" thing.
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    spokanespokane Member Posts: 514
    Prophet2 and Isellhondas, you are quite correct in your observation that refrigeration systems designed for R-12 will have a reduced cooling capacity when converted to R-134a. Capacity reductions of 10% are typical for stationary systems; I expect this is true for automotive applications. Even the EPA (see oldjunklovers post #7 above) acknowledges that this conversion will reduce the system cooling capacity. The energy efficiency, as measured by the BTU of cooling provided per KWH of compressor energy required, is also reduced.

    Providers of the R-134a conversion equipment are doing a disservice if they fail to inform customers of the performance reduction. In fairness to them, however, they probably don't have sufficient information to quantify the amount of the reduction.
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    tcvehlovrtcvehlovr Member Posts: 1
    If conversion works (r12 to r134a) without having to change any components, other than what is in the conversion kit you can buy or getting a reasonable price from an a/c shop how else do you get your a/c in the older car to work, be it a 10 year old one where enough r12 has seeped out over the years or finding a 60's car with factory a/c.
    the r12 can be priced at $50/lb, the r134a qiute a bit less. If you are overhauling the engine in a collector car and you can put in hardened valves and seats to allow you the usage of unleaded (the ethanol issue aside here) gas wouldn't you do it?
    You would be, in effect, retrofitting the a/c system to the current times.
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    mimeliomimelio Member Posts: 6
    My 1993 Ford Aspire had
    a great air conditioner.
    Then a leak sprang in
    the receiver drier.shop
    said now would be the
    time to convert to 134A,
    well city performance is
    now much less (cold air
    that is)but is nice and
    cold on highway.I wish I
    never converted!this car
    had a great air
    conditioner and now is
    fair,I wonder how others
    have fared.
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    alfa2600alfa2600 Member Posts: 3
    Soon you won't have a choice - R12 supplies are drying up. I had my '86 Mercury Grand Marquis converted and have had no reason to regret it. The only time it failed to keep the car cool on he lowest fan speed was on a 110 degree day driving west here in Texas last summer. However, this car has a fairly modern and efficient compressor. Certain older Fords, independents, British, and European cars use a York 1-cylinder compressor, and these will definitely loose cooling capacity. You can help the system by using an electric booster fan for the radiator, wrapping the receiver-drier with insulation, and replacing bothe the evaporator and the condenser.
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    wolfgang7wolfgang7 Member Posts: 2
    My '91 Tempo wasn't holding a charge anymore, so I had it retrofitted by an ASE certified mechanic at a local garage. They insisted on replacing the lines between the compressor and the evaporator/condenser units and with a new dryer and a charge with R134, it cost close to $500! Two days later, no more cold air. The compressor blew and had to be replaced ($350), then another recharge and with labor, again nearly $500. So for close to a grand I have a cool car again. My friend bought a conversion kit and coolant and did his '89 Tempo for less than fifty bucks! He says the old Freon already leaked out so he didn't bother with evacuating the system, just added new oil and freon. Works for him!
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    illusionsillusions Member Posts: 2
    4,500 O.B.O.
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    dwicksdwicks Member Posts: 1
    I restored a 72 Corvette Coupe, factory a/c. The first time around I replaced the lines, and put in a rebuilt compressor(mistake). The compressor failed within one year so I replaced it with a new compressor and new condensor. Since the lines were new, the shop only had to flush and evacuate the system and fill with R-134. Performance is slightly reduced but the vette interior is small. Biggest problem is the heat absorbsion from the exhaust. Hint: put a shut-off valve on the heater water line so no hot water enters the heater coils. That reduces the cockpit temperatures some.
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    HenryHenry Member Posts: 1,106
    I still have two large cans of the R-12 freon that have been sitting in my closest for years. I bought them when the auto shops still sold the stuff. Any suggestions on what to do with them???
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    spokanespokane Member Posts: 514
    Your R-12 is valuable. A licensed A/C repair shop, with equipment for servicing R-12 systems, would probably be interested in buying it from you at a price somewhat less than what they normally pay.

    Whatever you decide, please don't dump it in the landfill or vent it to the atmosphere. As you are surely aware, that would contribute (albeit very slightly) to the ozone depletion problem that led through legislation to the huge runup in R-12 pricing.
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    bigsnagbigsnag Member Posts: 394
    Anyone else use Freeze 12? It's some type of refrigerant that is not controlled by the EPA, but can be used with R12 systems. I've even heard of people putting like 1 can in on top of the R12 that was left and having great results. I personally wouldn't mix the two, but it does work. I think it even gets colder than R12.
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    Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    I think this creates lots of problems, in that when a shop evacuates a system that has a mixed coolant, then his entire stock of coolant is contaminated. This is why some states, like California, is requiring shops to buy a coolant detector, so that contaminated coolants can be identified prior to their being mixed with the dealer's stock. I guess some people are even using propane (yikes!) in order to avoid the expense of R12.
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    ab348ab348 Member Posts: 19,219
    I'd take the stuff off your hands... ;-)

    I wish I could get R12 here in Canada anywhere. You cannot -- it is illegal here to do anything to an R12 system without converting it to 134. This, I do not want to do as all reports I have read speak of lots of problems: higher pressures making things more leak-prone, lower cooling capacity, more frequent compressor failures, etc etc. From what I can gather R134 is an inferior refrigerant in just about every way. I find it incredibly curious that the refrigerant manufactuers like DuPont seem unable to produce a good R12 replacement all these years later.

    2017 Cadillac ATS Performance Premium 3.6

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    bhill2bhill2 Member Posts: 2,483
    My memory, as well as that of umfl (post 2) is that at least one R12 replacement exists, but has not been approved by the FDA for automotive use. At this point, I doubt if we are going to hear any good news. The approval process is very expensive, and since all automakers now put R134 systems in new cars the customer base for such a replacement is small and getting smaller. It just wouldn't make economic sense to try to bring it to market.

    2009 BMW 335i, 2003 Corvette cnv. (RIP 2001 Jaguar XK8 cnv and 1985 MB 380SE [the best of the lot])

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    berkelyblueberkelyblue Member Posts: 9
    I've seen them marketed under the name of Enviro-Safe, and the previously mentioned Freeze 12, and some Du-pont product that is a replacement, they claim that it works in R-12 systems and can be mixed. I'm gonna buy a kit and try it, since my car has no A/C now, the freon viewing windows shows less than half the Freon. If anyone else has any experience please post here!!
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    rea98drea98d Member Posts: 982
    Is that the FDA, or the EPA? The FDA is the Food & Drug Administration, and they could care less what your car does. They're concerned with things like making sure my whopper doesn't have dog meat in it, and my prescription medicines don't kill me. EPA is the Environmental Police Agency (hehehe), and they're the ones who worry about the ozone, cat converters, emissions, ect ect.
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    bhill2bhill2 Member Posts: 2,483
    Sorry about the reference to the FDA, I work in heath care research and it was automatic. Anyway, yes I did mean the EPA.

    2009 BMW 335i, 2003 Corvette cnv. (RIP 2001 Jaguar XK8 cnv and 1985 MB 380SE [the best of the lot])

This discussion has been closed.