MoogieBoogie

My air conditioning is out. It was working last summer when I bought the car, and also worked fine for the previous owner without any problems. I'm not sure if it would be a leak, but I doubt it. I'm guessing that it just ran out of refrigerant.

So I'm left with a choice:

1) convert from r12 to r134. My mechanic told me he just did one for a SC400 and it came out to about $500 total, parts and labor. He said the conversion wasn't too difficult, he needed just a few parts and it was easy. This way, if I ever run out or even if I have a leak, it'll be only about $60 to fill up with refrigerant.

2) fill up with r12 again. He told me it costs about $5 an ounce, and the SC models take in about 3 lbs. So that's 48 ounces x $5 = $240 plus labor to check for leaks and pressure test.

From searching through past threads, it seems that most people prefer the R12 refrigerant over the R134 because it cools better. Is it that much better? With my other car, R134 is cool enough. When I had my Maxima, setting the climate control at 65 degrees wasn't that cool. That was the lowest it went.

What do you guys suggest? Have any of you been in a similar situation?

Thanks,
-Brian.

AutoCoutureSC

iTrader: (8)

i always thought the conversion was a bit cheaper than that? i want to say around 300, but don't quote me on that.

IF and WHEN i do need to fill up my AC, i'm not going to do the conversion. I read on some old threads that the AC wasn't as cold or "strong" when the conversion is done. I don't know.... but I got quoted $150 to fill mine up with the old stuff.

Philly#1 Lex

iTrader: (2)

The R12 is stronger. If you like cold, cold AC in the summer stay with the R12. From all the threads that I read about the R134a its just doesnt blow super cold. If I was you I get my compressor and lin es checked to make sure there are no leaks and go get another quote on the refrigerant, I paid 80 buck last year when I recharged mine

Philly

mmarshall

I would go with the 134 conversion...or get a newer car with the 134 system to start with. R12 is no longer produced in much of the world (since 1995); it is expensive, and will probably become more so later. There are temporary stockpiles, but they will soon be gone. And you have to be a certified mechanic (probably ASE) to buy the R12 that is left.
Once again....thank Big Brother. The Clean Air Act of 1990, among other things, mandated the changeover to R134 because the R12 tended to leak into the upper atmosphere.
The good news......with most cars, R134 seems to cool just as well, if not better, than R12. My IS300...an R134 car...has A/C that blows ice-cold on a 95-degree humid day. So did my former car...a 1995 Celica...also an R-134 car. So do most of the R-134 cars I've seen.

mikeloc24

MoogieBoogie, I just went through this same damn thing myself last week. I went to get an oil change from a shop near my house (they charge me $13.99 for the oil change so yes, I pay SOMEONE ELSE to do it) and remembered that I haven't had a/c for about a year. I thought "I live in Los Angeles and summer is coming, go ahead and get the a/c fixed you cheapo!" so I had the mechanic explain some things to me. As previously in this thread R12 is colder than R134, but it is also more expensive ($69 per lb vs. $29 per lb). The conversion would have cost me $450 and to simply refill my system with R12 and pressure test for leaks and such would be $225. I thought it over and decided NOT to convert my system. The lowest the temp got in my car with R12 was 37 degrees, now that's an artic wind for your azz!...the R134 I was told would only get the temp down to about 48 degrees or so. I know this is technical as hell but I just didn't see any advantages to converting my car based on the info I had. I'll worry about converting to R134 when there's no more R12 available. Bottom line: if you want it as cold as possible then keep the R12 system, if you can live with it not getting so cold and you want to save a few bucks down the road then do the conversion.

siniquezu

Or you can rip out everything, do the conversion, and change your compressor and expansion valve before they go bad.

squarehat

The R-134a system on my '96 ES blows as cold, if not colder, than any R-12 car I've had in the past. I have no idea if retrofit applications (on pre-1994 cars) are significantly less cold than newer cars designed for R-134a.

saber

MONEY SAVING FACTS ABOUT R12 THE AIR CONDITIONING INDUSTRY
DOES NOT WANT YOU TO KNOW:

1. R12 systems are far more reliable and durable than converted systems.
2. R12 systems converted to R134a do not cool as well.
3. All drop in substitutes for R12 degrade system reliability and durability or
are flammable (e.g. maxifrig) in a front end traffic collision.
4. R12 is cheap and always available on ebay in 12 oz or 14 oz cans
and will be for years to come.
5. R12 charging hoses are also cheap and always available on ebay.
6. After the auction, most ebay sellers will not ask to see your license
to buy R12 refrigerant.
7. If you want to get your R12 license anyway, it costs only $15 to take
the test. The test merely involves passing a short, 25 question,
multiple choice, OPEN BOOK test that you take online or via mail.
In other words, since you can look up the answers to the test, it's
impossible to fail.

Ebay auctions for R12 refrigerant and charging hoses:
http://tinyurl.com/39t4c

Here's where you can take the $15 test to get certified
to buy R12:
http://www.macsw.org/macs.asp?mfurl=certify.html

MoogieBoogie

Saber and everyone else.. thanks for the information.

It seems that the Lexus SC has AC diagnostics, but when I pushed the "auto" and "recirc" buttons together at the same time, nothing happened. Did I do something wrong? Is there any way to check and make sure that it's the refrigerant that is out?

I know that the AC compressor uses some type of oil. How would I go about putting the oil in? Is it a simple procedure? I decided to stay with the R12 refrigerant.

Also, is the recharge something I could do by myself? Anyone know how many pounds of refrigerant goes into the Lexus SC models?

Thanks everyone again,
-Brian.

MoogieBoogie

Bump.. please help if you can.

1) Does oil have to be added to the compressor? How do you put in the oil? Is it like an AC recharge by connecting the hose to the low side port of the AC lines?

2) How many ounces of R12 goes into SC300/400 models?

3) Do I need anything other than the R12 cans and the gauge/hose kit?

4) Is flushing the system necessary, or can I just unscrew the low side cap, and plug in the gauge/hose and R12 can?

Thanks,
-Brian.

saber

1) The oil doesn't need to be replaced, nor does the oil level need to be checked except in cases where a system componet is replaced. In that case, the factory repair manual explaines how much oil needs to be added depending on the component replaced.

2) 30 ounces if the system is completely discharged of all refrigerant. 30 ounes = 2 1/2 12 ounce cans of
R12 refrigerant. If the system is just low on refrigerant, it may only need to be topped off with 1 can or 1/2 of a can. I add small amounts until the temperature of the air coming out of the center dash vents is
about 42 degrees or colder.

3. No, but you first need to determine if the system is really low on refrigerant or is not working for
some other reason. Example: maybe the system expansion valve is faulty. You have not explained the symptoms the system is exhibiting.

4. Flushing is never necessary if you stick with R12. But if the system ever becomes totally discharged and / or a system component is replaced, then the system needs to be vacuumed with a vacuum pump for 20-30 minutes and the receiver-drier (contains a dessicant) must be replaced, before adding a new charge of refrigerant.

Kansas

The A/C in my previous LS (a 1990) was converted in to 134 for around $300 in the summer of 2002. The only difference I noticed was that the fan speed seemed to sometimes run at a slightly elevated level. But the car still cooled down very well. I remember sitting in it with last summer with three other people at Royals Stadium for about 30 minutes with the outside temperature at nearly 100 degress. And this doesn't include the added heat rising from the asphalt parking lot. We were nice and comfy and the coolant temperature gauge barely moved above normal.

gserep1

Hello again,
R-134A systems are generally not as efficient initially as R-12 systems, because it is missing one very important ingredient: CHLORINE. It is the chlorine that causes the rapid decrease in temperature. It is also this same chlorine that is responsible for the depletion of the ozone layer.

The breakdown is like this:

HFC refrigerant. Hydrogen, flourine, and carbon. R-134A

CFC refrigerant: Chlorine, flourine, and carbon. This is R-12 Very bad for ozone

HCFC-22 refrigerant, Hydrogen, chlorine, flourine, and carbon. R-22 used in industry and government equipment. window air conditioners, and refrigerators years back. Very bad because it also has chlorine. Newer refrigerants and air conditioners sold today in stores has R-134A

Many things go into changing refrigerants over from R-12 to R-134A.

First of all R-134 requires different seals, both in the compressor, and in places where lines are joined together.

Secondly, the compressor oil must also be changed. The oil used in R-12 is mineral based, and the oil in R-134A is synthetic. The synthetic oil is called "PAG" oil. PAG being short for a 20 letter chemical word I have trouble pronouncing. Using R-134A in a system with mineral oil is creating a nightmare. The system will clog up, and the oil will turn in a syrupy goo, and get into all the small orifices in the entire system. Complete replacement is necessary after that. A quality retrofit will be done by a professional, who will use nitrogen to remove every trace of mineral based oil from the system. The filter drier will be replaced, as well as the orifice tube. The proper oil will be added in the proper level. Just a trace of mineral oil and R-134A together will cause a problem, and the proper cooling will never happen.

Because R-134 does not have chlorine, it is not as efficient pound for pound with R-12. That is why R-134 systems generally have more refrigerant, and bigger evaporator and condenser coils. If the system is modified correctly..(such as in a new R-134 equipped car), it will be just as efficient as the old R-12.

The R-134A boils at a different temperature than R-12, so a new orifice tube will have to be installed. This will be one calibrated to work with R-134A.

In addition, all fittings connecting the system together have to be "zero-loss" fittings. These are designed to reduce the loss of refrigerant when the lines are attached and removed while charging and discharging the system. Zero-loss fittings are required on all R-134A systems. We call them "quick-disconnect" fittings, because they snap over the lines instead of unscrewing on and off the line, like the old fittings. This is where so much refrigerant leakage occurs.

The R-134A fittings are bigger, so you can't make a mistake and put the wrong stuff in. The old hoses simply will not work on a new system. PLUS, R-134A fittings are different sized between the suction (low) side and discharge (high) side of the new system. On the R-12 systems, the fittings are the same size, and many times people connect a low side line and can to the high side of the system with disastrous results...(cans blowing up in people's faces, ect). Now it doesn't happen. You can't go wrong.

Getting a "cheap" retrofit will result in these mistakes being made, and the mistaken impression that retrofitting doesn't work. R-134A WILL get cold after a while. The R-12 with chlorine reacted nearly immediately. That is the only difference I have ever seen.

I would be careful using the old-fashoned gages and R-12 from vendors on EBAY. Federal law requires that all servicing be done through a "recovery system". The service centers pump everything out, clean it up, repair the system of leaks, and recharge. Nothing is to be vented into the atmosphere...(including the new R-134A.). Using the old screw on guages is illegal, and can result in a fine of up to $12,500 by the EPA. Besides, if a knowledgeable person sees you doing it, THEY can get $5,000 dollars for turning you in. It really sucks, but that is the law now.

People working with R-12 have to be licensed, to ensure they know what they are doing. R-12 will go up even higher in costs as the stocks deplete. Sometimes you can get refrigerant from places like Mexico at a cheaper rate, but you do not know what you are getting. This will probably not be "virgin" refrigerant, and could be contaminated with many things. BE CAREFUL!

By the way, I am not a dealer, or service center. I am an Instructor/Technical representative for the Dept Of The Navy. i have been teaching this stuff for about 19 years.(since the laws came into effect). I certainly don't want to come off as a smart-aleck, but this is stuff I know. If you decide to retrofit, don't cut corners. You'll regret it if you do. Quality installers do quality work.

You have to decide if you will keep an old car long enough to merit changing it over to R-134. In my case, it wasn't. All 4 of my cars are newer than 1995, which was the year everything had to be changed over on new cars.

Cadillac, BMW, and other upscale cars had R-134A as far back as 1993. If it worked in the luxury cars, it would work in other cars as well. They always try leading edge technology on cars people are willing to pay big money for. The only problem is: bigger cars have bigger systems, and they work better because of that. 1994 was the changeover year, and many cars got it that year. After that, it was practically mandatory for everybody.

I am used to R-134A now, and I have adjusted to the fact that initially it doesn't get as cold. But drive a new car around for a few miles...It will be just as cold, if not colder.

Just my 2 cents...(or was it 5 or 10 dollars??)

Sorry if this was boring for anyone....just trying to help someone like many have helped me.

GSEREP1

RollModel

why don't you just go to www, AutoRefrigents.com and get something that mixes with everything and forget about r12 and r134 Paladin...

sakataj

iTrader: (182)

EDIT: JUST NOTICED THIS POST WAS REALLY REALLY OLD AFTER I WROTE ALL THIS UP, I DIDN'T BUMP THIS INITIALLY BUMP THIS THOUGH LOL

OP also u said u not sure bout if it has a leak, i would def find out if you do before you do any of this. IF you have a leak they have a additive that you add that will seal leaks and is safe.

made by a company called cliplight

http://www.cliplight.com/

we sell tons of it for residential HVAC units but we do carry and sell some for the auto's.

here it is

http://www.cliplight.com/automotive/...tID=16&catID=4

actually, nowadays i prefer hotshot (R-414B) or one shot (R-422C). hotshot isn't truthfully a straight drop in to 12 because of the pressure differences but people do it, i myself have done it and you will be fine with it.one shot is a direct drop in. i personally have hotshot in my gs and can get it to sub 30's in the car. i would always have recommended 12 but due to its scarcity (they phased it out) and price nowadays i don't even bother with it anymore. (according to www.AutoRefrigents.com they want 720.00 for a 30lb JUG of R-12, OUCH) but their prices are mega high....we sell individual jugs of R-22 to our contractors (not cash, joe schmoe guys) for almost the price they giving for a skid price. i will tell you though, R-134 is gonna spike up and down over the summer. it hit astronomical prices last summer due to a shortage in europe but it seems to have settled down now

the hotshot is also available in a 10oz can although the standard can for it is a 25lb jug and i think the one shot is ONLY available in a 24lb jug

can find out info on hotshot and one shot from here

http://www.icorinternational.com/index.html

BTW i still have a few jugs of R-12 in the garage and can sell if anyone wants it, plus many other freons. oh....i manage a HVAC supply house locally in town so can come across just bout anything people need for HVAC-R

suggested above