Junkman

It has been a while since I have looked at this thread, so I will respond on some of the older posts with comments interspersed, but not in the order that they were posted.





No, it isn't inexpensive, but the labor involved is the greater expense, even if you are doing it yourself. If you think that your time is free, then consider what you might be doing with those hours, if you weren't fixing your air conditioner for the 2nd, or 3rd or more time.


I have no idea what R12A actually is, and once you install it, you will have "contaminated" the entire system with this "new" refrigerant. I have a strong suspicion that it might be one of the newer propane derivative gasses. If for any reason you need to service the system, once you use a gas that isn't widely accepted, no one will be willing to collect this gas, and you will have no choice but to vent it to the atmosphere. I did read the manufacturers statements as to it meeting the UN Montreal Protocol, and the statement ....



I strongly recommend that you use a good quality air conditioning flush, noting that items such as mufflers, receiver drier, and the compressor, cannot be flushed. Flushing is specifically recommended for the evaporator, condenser, and straight through hoses. I wouldn't use a stop leak, since it is more than likely it will gum up the system and cause you more problems than it might cure. A properly serviced system should be tight enough to hold a vacuum and a pressure test prior to installing the refrigerant.


Having owned a number of Mercedes, I can say first hand that just because the Germans used a product that doesn't mean that it is a good product. I owned a 1995 E320, which has a wire harness that was "biodegradable", and it started cracking and shorting out wires before it was out of warranty. Mercedes solution at the time was to individually wrap every wire under the hood. At that time, they had no other solution for the problem. That solution lasted long enough for the car to be out of warranty, but failed shortly there after. Mercedes refused to replace the wire harness, and said that it was a maintenance item. They said the same thing when the rubber air conditioning hoses failed.


Stick with good quality used GM or NOS, and forget about trying to retrofit R134A into a system that wasn't designed for that gas. I believe that this is why GM/Ford/Chrysler/etc. never manufactured retrofit kits for use in their cars of previous years.




This is an indication that the system had previously serviced, and improperly evacuated, and was contaminated with moisture. Some shops don't use virgin refrigerant, and install the refrigerant that they have collected from doing evacuations. It could also be a result of cross contamination of refrigerant oils. It would take an oil analyst to determine the exact cause. This is the reasoning behind flushing an old system that you have no history of its past service life.


The quality of the materials in some of the reproduction air conditioning condensers and evaporators is no where the quality of the original GM parts. Find NOS whenever you can, and they will always out perform the reproductions.



If you are planning on returning to R12 at some time in the future, start collecting all the necessary part now, since they are going to get harder to find in the future. In many instances getting the R134A fittings off of the R12 fittings is going to be difficult, if not impossible. Originally, they had barbs that would dig into the original threads if you tried to remove them. I have been told that the newer ones don't have this feature, but never having done a conversion in recent years, I can't say for sure. After having done a few conversions from R12 to R134A, with mediocre success of sufficient cooling, I realized that the savings of R134A wasn't worth the extra work to put it back to R12 when someone was dissatisfied with the cooling of the system. A system that was designed for R12 will always work better than trying to retrofit a R134A system into it. To me, it is like trying to adapt a Ford part to fit a GM car. It can be done, but at what cost?????

Olds64

Thanks for the input. I've been doing some browsing and apparently there are even folks out there that use difluoroethane from computer air dusters to recharge their AC:


To me this seems a bit like jury rigging an AC system. While I might be willing to use r12a or freeze 12 to recharge my AC system, I don't think I would be willing to use this trick. Thoughts?

71Convertible

I've only done one A/C conversion and it was on my 1971 Cutlass Supreme convertible. I did this about 4 years ago when I had the entire power train out of the car. I'd previously done seal replacements on the older GM R12 compressors. That and availability/cost of R12, I felt it was time to move away from that compressor design. I replaced all of the R12 components with R134 components. My Cutlass isn't a show car so I wasn't concerned with the different look in the compressor; though I did save the original R12 compressor and mounts if I or someone else wanted that all put back. In the warm, humid coastal Virginia climate, I find that the R134 cools very well. I run the A/C on hot humid or rainy days when it's not comfortable to have the top down.

Olds64

Don, you mentioned that you installed r134a components. Did you just install a Vintage Air system or did you replace pieces individually so you could run r134a?

71Convertible

In 2012, I purchased and installed items from Classic Auto Air, Tampa, FL. for my 1971 Cutlass Supreme convertible. This included the replacement compressor with mounting bracket, POA valve, condenser, dryer, evaporator and all hoses. They were good to work with and quickly resolved the only issue that I encountered with the parts I purchased. I decided there was enough corrosion/oxidation on the 41 year old condenser and evaporator that I would bite the bullet and replace it all when I had the engine out of the car for rebuild. Here is a picture from today, showing some of the components.

zeeke

And you missed the biggest reason of all R12 is dichlorodifluoromethane which has no upper or lower explosive limit and propane is dimethylmethane which is a completely different chemical with different carbon bonds and has a UEL of 9.5% and an LEL of 2.1%. In other words R12 is not Propane. Another point to mention, with propane, the flame cannot travel into the lines due to the lack of oxygen so it can only burn in the vapor space which needs to be between 2.1% and 9.5%. To rich or lean it will not burn.

What we see in the movies with gas tanks on cars exploding doesn't happen, they rupture with a sudden rush. Just like that propane video. I've been to hundreds of car fires and have never once seen the violent explosions portrayed in Hollywood, however a propane tank can BLEVEI which will cause a much more violent rush.

The violent flame you see from R12 freon is most likely caused by the gas escaping and creating a vortex introducing more oxygen to an already burning fire.

The reason R12 was no longer manufactured is the damage it does to the ozone which protects us from the sun. R134a was its replacement.

FarmerDave

That's not how it works. Flames don't travel thru the hoses and thru the system. Just like the flame doesn't go from your bbq burner thru the hose and into the tank and explode. There needs to be enough oxygen in the mix to support combustion. The small amount of gas would just burn off in the engine compartment once released to the atmosphere if there was a fire and a leak. I would be more concerned with the gasoline that is pumped to the engine.
R290 (propane) has been used for decades around the world. And R12a is a mix of propane and butane.

bw1339

Another vote for R152A (which is a proper refrigerant commonly found in keyboard duster sprays):
Click on link to watch on youtube - Won't let me embed.

dc2x4drvr

Old thread
Has anyone actually used RedTek or another R12 clone, if so, please share your results.
I have redone my ac system with new dryer, etc, and I have a few cans of Red Tek ready for installation, hopefully it works as advertised.

69HO43

Talk about NECROMANCING!!!!!!!

I'm going to use the 152a (computer duster) refrigerant in an experiment when I recharge my 85 442 system with new components and a newly resealed R4 NOS compressor. R4s are notorious for leaking around the shell o-rings and front seal. Just use oil for a 134a system and recharge a smaller amount of R152a and it should be fine. Has close pressure/temperature chart comparisons to the way R12 reacts, so the pancake compressor should live just fine. There's some reports that said there's a potential of shortened compressor life, but haven't heard of any real life issues. It's actually more environmentally friendly than 134a. The slight issue is the flammability part as it is a bit higher than the lowest level where R1234yf is.
The R1234yf stuff in the newer cars is a flammable risk too, they just don't like scaring people with that fact.

I got some R12 too, but we'll see how it goes.

Olds64

I ended up using Red Tek Freeze12 (R12a) in my 86 F250. It worked great. Unfortunately it all leaked out. I tried to charge it again but couldn't get it to blow cold. I think I need to do some maintenance on the system.

I still drive my 71 98 without AC. We'll see how long that lasts.

bw1339

R152A in a 72 Buick.

Lonnies Performance

I've used Frosty Cool R12a in a few vehicles with good results.
It requires 35% by weight of R12 & 40% of 134a.
The cans are 6oz to help with the ratio.

It definitely cools better than 134a.

Yes, it is flammable but consider the volume of actual gas in your system...
it is not a huge volume & also the oil (which is mixed with the liquid freon) in there is flammable which can ignite if you rupture a hose anyway.
I've run it for a few years in multiple vehicles with good results.

I also recently used it in a 134a vehicle where I added a refrigerated intercooler for the supercharger.
I wanted the colder temperatures that it could provide with good results.

olds 307 and 403

Interesting on the flammability of these A/C and it is a bit scary. I have done a few of the R134A conversions a few years back. They worked OK up here but we see 40C (105F) max up here. Usually more like 30C to 35C or 85 to 95 Fahrenheit in Summer up here and only a few weeks of it. Only our cities have any amount of stop and go traffic to really test it. We did the R4 compressors, would grab any quiet used ones, would usually take a few and they would leak and usually pile up at some point. I did the Redtek 12A with their oil in my 88 Cutlass. It cooled quite well but it eventually, leaked and seized like a R4 compressors do. I may do an aftermarket system on my 70S at some point with a Sanden compressor in the SBC serpentine setup with some sort of aftermarket setup which looks like they use R134A which should work well in a system designed for it.

bw1339

One factor we often overlook is that the fin and tube condensers in our cars are very inefficient and get very poor air flow (in my '66 there is no shrowding to duct fan air through it). Putting a big electric fan on the condenser, or replacing it with a modern parallel one makes a big difference, regardless of refrigerant used.

Also, the POA valve may need to be adjusted for the characteristics of the refrigerant being used.

Fun71

yeah, I noticed that one day while working on the cars. I measured the fin spacing and found the Cutlass had 11 fins-per-inch compared to the new (at the time) 1998 that had double the fin-per-inch count. Made me thing just a better condenser would vastly improve the cooling capability, especially in the Phoenix 110+ summer temps.

bw1339

Next time it's warm, pour some cold water on your condenser while running. If you see a noticeable drop in A/C temperatures, you could benefit from improvements there, either in a more modern condenser, auxiliary fans... Or both.

Funkwagon455

Reasonable price for a great product. (35 degree duct temp at 95 degree oat on my way home today.😀

twilightblue28A

Anyone have R12 for sale? Please send me a private message. marjunx has R12 for sale, but I can locate his original message. Thank you for your help.

bw1339

Check Facebook Marketplace.

chip-powell

Maybe I just lucked out. I converted my system over to 134 about 4-5 years ago. Other than checking it (and sometimes having to top it off) in the spring, it blows nice and cold all summer (knock on wood). Given, I don't live in Phoenix like Ken so I'm not dealing with 110 on a regular basis, but for a few hours cruisin' in summer temps in the low to mid 90s, my wife and I have been very comfortable.

Junkman

I can't say you are correct or incorrect, since I have no personal experience with this happening, however, what you have said does sound reasonable. I was told about the "explosion" hazard by my supplier of acetylene, who was discussing why you should have flashback check valves on your cutting equipment. Once again, I have never experienced a flashback on my oxy/acetylene setup, but after the discussion, I did install the valves. I prefer to learn from other's experiences rather than make avoidable mistakes.