Hey All,
I've been reading a lot of the posts about freeze 12. My 83'240D has been copnverted o r134a. i'm not thrilled with the ac. i was thinking about converting to freeze 12, but have been kind of surprised by the attitude i get about it. here on this site and at diesel giant,which has a great pictorial on it, it's praised as the greatest thing since sliced bread. everyone here in gainesville,fl that i talk to say that it's been implicated in explosions in vehicle crashes and will probably be banned soon and they would not recommend it. since the compressor on my car is a relatively inexpenseve GM type, i guess i can afford to replace it if it blows, which always seems to happen when r134a is put into an old r12 system. I'm just kind of curious, does nobody here share these danger concerns? Has anybody even heard about them? I need to make a decision, because summer is well on it's way here(will be 88 degrees today), about what to do with my ac's lackluster performance.

Cheers,

Dale

First, Freeze-12 is not explosive. The people telling you that are not familiar with the product, they are confusing it with other R-12 substitutes. Some of the other substitutes are made of propane and isobutane - basically barbeque grill gas. Hydrocarbons such as these actually make pretty good refrigerants - they are efficient and cheap - though of course flammable as well. I recall the hydrocarbon substitutes were sold under names such as Envirosafe, EV-12, and similar.

Second. Freeze-12 consists mostly of R-134a, It is 80% by weight R-134a. The remainder consists of one or two other refrigerants. As such, it performs pretty much the same as straight R-134a. Certainly it can perform somewhat better, but since it is mostly the same stuff, it performs mostly the same.

If you really want better cooling the best approach is to convert back to R-12. Yes, that will cost more than F-12, but you will get better cooling and more bang for the buck spent.

- JimY

i say HOGWASH to any buzz about explosions related to use of hydrocarbon based refigerants.this stuff has been in use for years all over the world and to the best of my knowledge theres has never been a confirmed incident.a fully charged a/c system would only hold a few pounds.how much of that would actually get released to the atmosphere in a typical leak situ?

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michael cole 1980 300SD gone now but not forgotten,87tdt,90 300te 4matic 95 e320 wagon

A couple of pounds of propane will start quite a fire - I agree the chances of having an accident that would ignite a propane based refrigerant is pretty small but with genuine R12 selling for $15-20 a pound I roll my eyes when I hear of people that are willing to take the chance of incinerating themselves to save $50 on a car repair.

Hyrdocarbon based refrigerants are illegal for use in mobile A/C systems.

r12 is still available in the USA of course.up here in the great white north winters are long and summers short and usually hot.the only viable option for older a/c systems here because of enviormental law is hydrocarbon type refrigerants.they are easy to use and readily available.thanks to these products i was able to enjoy a/c last summer in my 80 300sd which still has the original compressor,evaporater and condenser

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michael cole 1980 300SD gone now but not forgotten,87tdt,90 300te 4matic 95 e320 wagon

check out this link for more info on alternative refrigerants.i personally recommed this product as it has worked in 2 of my vehicles.http://www.redtek.com/products_refr.html

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michael cole 1980 300SD gone now but not forgotten,87tdt,90 300te 4matic 95 e320 wagon

Alright. Now I'm even MORE confused. Are hydrocarbon based refrigereants legal or not? if freeze 12 is 80% r-134a what's the point of using it over 134a? I'm worried about blowing my compressor seal as a result of the higher head pressures of r134a. at the same time i don't want to pump my system with something that is not readily available. i'd LIKE to be enviromentally friendly, but not at a prohibitive cost. Red Tek website says it IS hydrocarbon based but shows a video of someone using their product in a car.
arghhhh!!!
also, off the top of anybodies head. what's the dilly-o with the different compressor oils that the different refrigerants require. Do any of them have downsides? mayb i should look at THAT angle for making my decision. I'd like to get my ac set up so that it's as rock solid, low maintenance and reliable like the rest of my beloved 240D.

Thanks All,
Dale

"I'd like to get my ac set up so that it's as rock solid, low maintenance and reliable like the rest of my beloved 240D."
having stated the above goal your choice of refrigerant type is certainly important but not nearly as important as ensuring all components of your a/c system are in good repair and up to the task.

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michael cole 1980 300SD gone now but not forgotten,87tdt,90 300te 4matic 95 e320 wagon

I don't believe Freeze 12 is 80% r134a because Freeze 12 is compatible with R12 and r134a is NOT compatible.

See link for info (not affiliated)
http://autorefrigerants.com/co00030.htm

I use Freeze 12 in my RV as a replacement for R12 and it does just fine. I like the fact that no flush was necessary in between service. I just ordered some more on eBay for my 300D in the event the R12 begins to leak (not so far).

John

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John Hughes, was in Landstuhl, Germany but currently in San Antonio, TX


1978 280CE Astral Silver now 59,xxx miles and counting "Silber-Kugel"
1986 300E Black Pearl Metallic 143,xxx miles 5-spd daily driver w/ blk leather "Schwarz-Schönheit"
1989 190E 2.6 (euro) 5-spd Desert Taupe 112,xxx kms Had to leave behind in Germany!!! "Helga"
1983 300D Pastel Beige now 312,xxx + miles SOLD

OBK#24

i recently vacuumed down the ac system in my 74 450sel, added a can of esther oil charge and 3 cans of 134a. the high side reads 180, the low side 30, the air at the vents is 41 degrees. r-12 couldnt improve on this. compressor failures on 134a conversions are always due to excessive high side pressures as 134a builds higher head pressures than r-12. if you add the recommended 75 per cent of r-12 capacitity, head pressures will stay below critical limits. overcharged systems are also inefficient and will make the compressor run continuously. i plan on doing the same procedure to my 74 280 this week. for the past few years i've been using smuggled mexican r-12 which contains enough butane that you can use a torch as a leak detector. the torch flame noticeably increases in size when the leak is detected. is it dangerous? in the right circumstances i'm sure it would be. r-12 just isn't worth the effort and expense anymore.

Thinking my A/C wasn't working as well as it could, I bought a can of recharge stuff at Wal-Mart. Hooked it up (83 300SD, converted to r134) and the pressure was in the middle of the "ALERT" yellow area, 55 if I remember right. I didn't add more. I'm wondering now if it's too full and perhaps THAT is the reason it is somewhat disappointing...

What should the pressure be? If it's too high, how to I get it lower?

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1983 300SD, Silver/Blue, 230+K (rebuilt at 196K)

Rather than conjecture, before writing my original post I looked it up on the EPA webpage. Here is the URL: http://www.epa.gov/ozone/snap/refrigerants/refblend.html There is no question that Freeze-12 is 80% R-134a.

The mineral oil commonly used to lubricate R-12 systems is not miscible with R-134a. Hence it will collect in low spots in the system, fail to circulate, and starve the compressor with the eventual bad result. The mineral oil does not break down or otherwise degrade in the presence of R-134a.

There are two strategies commonly used by alternative refrigerant manufacturers to address the lubrication issue. Either they include within the refrigerant blend a component which is miscible with mineral oil and will move it through the system, or they include an alternative oil (e.g. Ester) with the refrigerant. It appears from a quick google search that the R-142b which comprises 20% of Freeze-12 is miscible with mineral oil, hence serves the function of moving the lubricant through the system.

- JimY

consider the total volume of your ac system, if you are losing refrigerant it is being replaced by air. adding freon wil increase the volume of the system, driving pressures up but because of the air in the system you still dont have the necessary amount of freon for it to operate properly. evacuate the system, find the leak and after it can hold a vacuum, recharge it. evacuating also removes the moisture that entered with the air so let the vacuum pump run at least 10-15 minutes. when recharging try to keep highside pressure under 200 and lowside around 50. this is done by NOT adding that extra can that you think it needs. trust your guages.

[QUOTE=jcyuhn]Rather than conjecture, before writing my original post I looked it up on the EPA webpage. Here is the URL: http://www.epa.gov/ozone/snap/refrigerants/refblend.html There is no question that Freeze-12 is 80% R-134a.

Jim,
You are certainly correct - I didn't look at EPA site since I'd been informed by an apparently uninformed AC technician that r134a was totally incompatible with R12 - I'm guessing he just didn't want to explain the whole lubrication issue - thanks for breaking it down. But the Freeze 12 does work well!

John

__________________
John Hughes, was in Landstuhl, Germany but currently in San Antonio, TX


1978 280CE Astral Silver now 59,xxx miles and counting "Silber-Kugel"
1986 300E Black Pearl Metallic 143,xxx miles 5-spd daily driver w/ blk leather "Schwarz-Schönheit"
1989 190E 2.6 (euro) 5-spd Desert Taupe 112,xxx kms Had to leave behind in Germany!!! "Helga"
1983 300D Pastel Beige now 312,xxx + miles SOLD

OBK#24

the bottom line here is that r-134 says on the can that its not
mixable with the r-12 and that you must completely purge the system...

the can of freeze 12 says.... dump it in with anthing....

so i have an old mb 83 300sd and it has r-12 but its low so i just top off
with freeze 12 and away I go....works fine... i did it last year and I will
do it again this year...