Where can I find R12?

[inshje01]

Okay, so I found out that it was just a bad connection between my Control unit and the wires that run out of it. I clicked that back in securely and the thing came on like a charm, compressor clutch spinning and all.

Now, I've got a question. According to the FSM, my vents should be blowing about 35-40 degrees F. I have not stuck a thermometor up to them, but they feel like they were blowing 60-70 all day today. This is about 30 degrees cooler than what they were blowing without AC, but still not up to par.

Should I just give this time to work itself out, or is this an indication of a different problem? The last time the AC worked, it was at 35-40. So, do I need to just let it run a while and let the system "get back up to speed," or should I be worried? Also, like I stated, I think my pressure is a bit high on the low side, ~40 psi, while the FSM states something like 15-25(?).

[ricebike]

it was really hot/humid that day around my area & my wife's ac felt that it wasn't running up to par...

temps vary w/ the outside temp/humidity... isn't there a chart to see what the range may be in during the time of day & humidity level?

edit: yes, there is a chart; for ex. if it was around 95 degrees and humidity was ~60-70%, then output temp is about 65 degrees F

i think the ac techs will need both readings for a more complete diag... heck, there's a whole section for that as well in the FSM it could range from bad expansion valve, air in the system, condensor, too much oil in system...

[FliMSiCaL]

an automotive refrigeration system in perfect operating condition will achieve at best a 35 degree drop from the inlet air temp. If you want it cooler on a hot day, switch to recirculate, it will drop the inlet air temp and over time, give you cooler air. 40 pounds on the low side running is too high. Too much refrigerant in the system will produce high head pressure and higher discharge temps, resulting in less cooling effectiveness. Cleaning your condenser and evaporator coils will help, along with changing out the expansion valve (requires emptying and re-charging the system) 240sx a/c systems were never all that great, mine didn't do well unless i was moving at a decent rate, or had the engine revved up some, and i lived in southern louisiana. Another note, "virgin" or new r-12 legally obtained is incredibly expensive now, with wholesale prices exceeding 70 bux a pound. You can however buy reclaimed r-12 for cheaper. Just make sure the seller can state that it meets ARI 700 standards for purity. Cross-contaminated r-12 causes lots of issues especially in cars where the compressor has an average temp of 150 degrees.

[inshje01]

Has anyone here used Freeze 12 as a replacement. Somebody over in another thread was talking about wanting to get it, but is in military limbo waiting for a mailing address.

Is this stuff as good as R12 or R134a? Or is it any good at all? I was just pricing some and it looked to be the same cost as R12, after I get all the fitments and such. If this really is a stupid idea, feel free to

[FliMSiCaL]

freeze 12 contains propane which actually can be used as a refrigerant. I don't know about you, but gasoline is pretty much the only fuel i want running around under the hood of my car :p. In all actuality, it is dangerous, if u get a leak, you end up with a large fire risk.

[benemorius]

More misinformation. Here I come again.

The vent outlet temperature and system pressures are directly dependant on several things. One cannot declare them out of spec without knowing the ambient temperature and relative humidity. You will find a graph in the FSM which will help you determine what your pressures and outlet temp should be for a given ambient temp and humidity, but I can tell you right now that 40 psi and 60-70 degrees would not be out of the question on a hot day.

Freeze-12 does not contain propane or any other hydrocarbon. Most blends which do contain a hydrocarbon contain butane or isobutane. The amount which they contain is not enough to be an explosion hazard. (most are between 1% and 4%) Of course, we are talking about the EPA-approved replacements here.

Hydrocarbons actually make splendid refrigerants. Many, including myself, are not certain that they pose a risk substantially greater than any other refrigerant. If you are interested, check out HC-12. It cools better and is cheaper than R-12, though is not EPA-approved for motor vehicle use.

I do not recommend the use of Freeze-12 for two main reasons. Firstly, it is a blend and as a general rule I do not recommend blends. Blends are subject to something called fractioning, whereby the blend ratio is altered over time due to the constituants having different rates of absorption/leaking. This can alter performance and much more importantly it makes recovery questionable. Now, many argue that this effect is minimal and I actually don't disagree, but the last thing we need is one more source of refrigerant contamination. The second and much bigger reason is that Freeze-12 contains an HCFC, which DOES deplete the ozone layer. The whole reason we are moving away from R-12 (a CFC) is ozone depletion, so why move to another ozone-depleter? The HCFC contained in Freeze-12 is scheduled to be done away with in the next couple of decades, as I recall, but why wait? It is true that Freeze-12 cools better than R-134a and you are free to make your own decision, but I have given you my reasons for not using it. If you must use a replacement, I would recommend R-134a (because it is pure and ozone-friendly) or HC-12 (because it is dirt cheap, cools VERY well, and completely environmentally safe)

[inshje01]

This whole thread benemorius has been my god, and HC12 sounds like a much better plan than Freeze 12. Also, would this be the ONLY replacement you would consider, or are there others, such as EnviroSafe 12a, that would even be worth looking into?

[FairladyZ4U2NV]

I looked up HC-12 and people seem weary to use it because it is flammable. Is that correct?

[benemorius]

I looked up HC-12 and people seem weary to use it because it is flammable. Is that correct?

That is correct. What can I say? Some people are just naive. Would you care to guess what happens to R-134a at 400* in the presence of oxygen? Yeah. Hydrocarbon blends won't do that until well over 1000*. And yes of course those are one-sided facts but as long as I admit that, there's no harm right?

ES-12a is another hydrocarbon blend, and I don't believe it is any different than HC-12a. I wouldn't use any other refrigerants, but that's not to say that none are any good. Really I'm just happy enough with R-134a and HC-12a that I haven't a reason to look anywhere else.