What is probably a stupid question: In an R 12 system, may one add Freeze 12 without changing any fittings or evacuating the system first? In other words, say the system is just down a bit, can one use the Freeze 12 with the existing R 12 in the system? Your thoughts would be appreciated.

Joe. B.

No

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The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

Not only is it a bad idea it is not legal. Mark

Not only is it a bad idea and not legal, but you will have trouble finding an AC shop to service it and to evacuate your "contaminated" R-12.

If the system is "down a bit" take it to a shop, fix the leak, than recharge with R-12.

Freeze 12 is 80% R134. You dont want to mix it with anything else.

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I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k

You guys are nuts. You can use Freeze12 as an add-in to your R12 system - that's what it was made for. People do it all the time.

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- Brian


1989 500SEL Euro
1966 250SE Cabriolet
1958 BMW Isetta 600

I don't doubt there are many people that do this - of course after reading this (and other boards) for a few years now it would not surprise me to hear of someone trying to use orange juice as a replacement refrigerant.

According to the Freeze12 website a Freeze12 conversion REQUIRES that all old refrigerant be recovered prior to refilling with Freeze12.

Call me "nuts" but I'd stick with the manufacturers recommendations.

Well, YOU can if you dare suffer the consequences. Do the math. r134 is not miscible with the mineral oil of r12. Freeze 12 is 80% of the main constituent of r134 - how miscible is that with mineral oil.

Freeze12 and similar products were made as SUBSTITUTES - not 'drop-ins', or 'add-ins' to r12 systems -AND they don't cool as well.

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1984 300SD TURBO DIESEL

No, it was made as an alternative refrigerant to R12 that was 'supposed' to provide similar cooling capacity at reduced cost. By law, you have to put on fittings for the a/c system that are specific to the refrigerant being used, and you cannot mix refrigerants. Shops cannot reclaim mixed refrigerant to be used elsewhere, so they are forced to pay significantly to have it disposed of properly. That YOU choose to break the law by adding it does not make it legal or advisable to anyone else.

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1987 Mercedes 300D

And despite any refrigerant manufacturer's claims to the contrary, by law there are no "drop in" substitute refrigerants. Mark

Freeze-12

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Hi there,
Most all the R-12 substitues are a blend of butane and propane, in a percentage to produce approximately the same cooling effect as R-12. They work fine as long as there's no leak in the system. They are compatible with both mineral and PAG oils. (I don't have personal experience with the PAG oils, however, just repeating what I've read.) They are actually more efficient at cooling than R-12 is.
The problem is that the system MUST be labled that there is an R-12 substitute in the system. Failure to do so is against the law! Also, if there is a leak in the system, (and there almost ALWAYS is,) the percentage of butane and propane will change, and then the system won't work as designed after awhile when one of the gasses leaks out in a greater percentage than the other.
Interestingly enough, these gasses are used in many countries around the world instead of R-12, completely legally. They are environmentally friendly, even when leaked into the atmosphere. There is a slight danger of fire if they leak into the engine compartment in a large volume, but no worse than a can of hair spray.
If one uses them be aware that the liquid volume of these gasses is much different than R-12 - it takes much less to fill the system. If I remember correctly, it's on the order of 1/3 the quantity by weight.
Don't try to mix butane and propane to approximate the same thing, as the substitutes like Freeze-12 have been filtered and more water has been removed from the gases. Using regular butane and propane may rust out the AC system from the inside out.
I am personally aware of a Jag that has been using this stuff for 7 yrs now with no ill effects...

I'm sure that others will have plenty to comment on regarding this subject.

Regards.
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Richard Wooldridge
'82 300D 4.3L V6/T700R4 conversion
'82 380SL, '86 560SL engine/trans. installed
'79 450SL, digital servo update
'75 280C

If you were to mix an after-market refrigerant with R-12, I might agree with this statement as Freeze-12 is 80% R-134A. Now the chemistry is out of whack.

I have seen 2 instances where systems were evacuated and recharged with Freeze-12 exclusively and the end result was vent temps 4 - 6 degrees cooler than with pure R-12. I'm not the only person to experience this.

However, if you're going to use an after-market refrigerant, use it exclusively and do not mix R-12 with it. Differences in pressure, oil requirements and what hoses can and can't take are but a few of the physical issues involved.

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Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

Absolutely true - but let me ask you a quick follow-up question.

Was the R12 system that you used for baseline comparison and subsequent Freeze12 conversion working properly with a full R12 refrigerant charge when you made your vent temperature measurements?

If the answer is yes I'd like to know why you bothered to switch to Freeze12, if the answer is no I'm not going to accept your anecdotal evidence.

Freeze 12 is compatible with R12 oil. Therefore, theoretically, it is also compatible with R12 and contains 0% R134a. It may or may not contain flammable hydrocarbon gasses, I didn't see that specified in my quick look at their site.

However, although you probably COULD mix R12 and Freeze-12 and have it work fine, it is ILLEGAL. You could be fined by the EPA - especially if you go to a mechanic who attempts to work on your system and finds it wasnt pure R12 and not pure Freeze-12. He might report you for the inconvenience to him because he then has to recover the refrigerant and have it disposed of instead of recycled.

Once again, it MIGHT work - it PROBABLY would. But WHY would you do it? Remember: Illegal. EPA. Fines, fines, fines! Unless your system has a serious leak - and then it won't have much R12 left in it (if any) anyway - your BEST bet is to spend the $50-100 to go to a shop and have them inspect it and top it off with ACTUAL R12! You said it's only a bit low, so get the real deal. Freeze-12 is for people with leaky systems with no R12 left to worry about removing anyway.

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Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

Previous:
1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k

I appreciate all your thoughts on the subject. I believe now that I will convert to 134A when I need to. Currently, my 1989 300SE is cooling pretty well--I found my last can of R12 and topped off with that, and it brought duct temps down to a reasonable level. I had converted my other MB, a '79 300TD, several years ago, and it cools pretty well. And of course, the 134A is readily available in recharge cans. Again, thanks to all who took the time to post.

Joe B.