boriqua

Howdy,

So I just bought my 89 camaro RS about a month ago and the a/c isn't working? Of course it is R12, which is the old standard, and I guess it needs to be converted into a R134 unit. Basically what I am asking is what is the best route to get the a/c working again? Is it an easy fix, should I take it to a professional? I live in Texas so all I really need is cold a/c, I can do without the heater.

Thanks

JamesC

iTrader: (5)

Why convert? Have it recharged with R12 and live happily ever after. I've never had any problem finding a shop to do the work--even in the boondocks.

JamesC

DJP87Z28

In these cars and there age the A/C system may require more then recharging. That is the big clue, no refrigerant in the system. So unless you want to keep pouring the hard to find R12 (most shops will not even handel the stuff) I would convert to the R134. You are going to be replacing parts anyways. Been there and done it.

JamesC

iTrader: (5)

Me too. R12 to 134 back to 12. Though I was dissatisfied with the cooling ability of 134 in my system, many board members aren't. A search might provide more info on which to base your decision.

JamesC

rideon1200

Find yourself a HVAC guy who wants to make some easy side money.(not hard in texas) Have him leak check your system and add "Hot Shot". It is a drop in replacement for R12. Will not dry out gaskets, no changing oil and works as good as 12. Any HVAC guy can find it in the parts stores. Will not hear about it a auto service stores. They want to make a quick grand. Hot shot is 9.99 a can, you will need 2 to 3 cans.

boriqua

I actually heard that there was a kit out there that would convert the R12 unit to an R134 just with a few simple pieces. You guys ever heard of something like that?

89RS_82Z

iTrader: (2)

134a in a 12 car leads to more leaks and problems, than just having it leaked check and having 12 or freeze 12 put it, plus 12 cools better than 134a

Reid Fleming

iTrader: (2)

I'd stay away from Freeze 12. It's 80% R-134a. The other 20% is hotter than R134a. They claim it works with R-12 mineral oil, but they also recommend switching to POE oil for better performance.

R-134a does NOT work well with mineral oil. So I wonder how Freeze 12 can advertise it as being compatible.

krisb410

iTrader: (9)

There are numerous refrigerants that are compatible with R12. I use Envirosafe and it is a direct R12 substitute. 6 oz. of that stuff is equal to 18 oz. of R12. I think I paid $7 for a 6 oz. can of it. I just used it to recharge my system, so it only took 1/2 a can.

I have had a few cars that had been converted to R134a, and they all sucked!

Another idea I had before I found Envirosafe, was to buy a car that had R12 in for $200-$500, take the refrigerant out of it, and either resell it, or part it out.

boriqua

Where would I find Envirosafe? Any auto parts store, online?

Thanks everyone!

jer4251

iTrader: (6)

im in the same boat with my 92. no cold air. dont want to spend a lot of money, its a ragtop, but one of my windows is stuck up. so it gets pretty hot here in georgia.

82 Iron Duke

iTrader: (21)

Gotta subscribe

89RsPower!

With mine I simply screwed the conversion fittings on, replaced the o-rings (they were the reason I had no r-12 left), changed the oil and charged it with 134a, it get's so cold I actually have to turn it off sometimes. No complaints here at all and it costed me a total of $25 to do.

mmadden55

Not a lot of help here guys. Thanks anyways. I think I am going to try the kit and see what happens.

89RsPower!

Old thread.. whats your problem?

mmadden55

I am trying to get an idea of what is really needed to do a R134a conversion to a R12 system. I am thinking I will try the converter kit. If it doesn't work out I will change the compressor and dryer and condensor as well. Might as well try it the cheap way first.

krisb410

iTrader: (9)

Did you see this?

https://www.thirdgen.org/retrofitac

I don't think you'll be happy with though, I've had a couple of cars that had the 134 retrofit. And they all sucked! It somewhat works, but not like it should.

DJP87Z28

It is going to be a retrofit or no A/C. R12 at this time is history and the substitutes are not worth the money. They are what they are called and not a long term fix.

Fast355

iTrader: (2)

R12 is FAR FROM HISTORY...Atleast here. I just bought a a 12 can case of 12oz cans for a very reasonable price from the local Orilley's auto parts.

arrowcamaro

iTrader: (2)

Not true on either account, sorry. You can still get 12 easily.

The 134 in a 12 system just flat out sucks, been there dont that. Im currently running a 12 alternative thats been working just fine with sub 40* temps at the vent.

DJP87Z28

If R12 is not HISTORY why are you buying it by the case?????

luvofjah

iTrader: (2)

I spent $250 on retrofit...
But system had a leak.. or 2...
Had evaporator replaced... ... parts & labor $400...still leaked
Had compressor replaced, system tested, refilled... $500 later..

Working great now for 6 months and blows cold... Just my experience...

Raf

arrowcamaro

iTrader: (2)

Did you read what you wrote? If it were "HISTORY" he wouldnt even be able to buy it by the case.

Its not history yet, its still out there.

Fast355

iTrader: (2)

I buy R134a by the 30lbs cylinder.

I do AC work on the side and pretty much would not convert a R12 system in this climate.

I installed new hoses on my girlfriends 92 Honda Accord recently. With R12, it was 94*F outside, 40% humidity, at idle, center vent, high blower, 37*F out of the vents!

My mom has a 1995 Acura Legend with the factory R134a system. Functioning correctly, it blows about 45-50*F out of the vents on high blower, in the same ambient conditions.

The reason I mention this is the A/C systems are almost identical other than the obvious fact the Legend has a bigger condensor.



I guess I won't mention I evacuated all the R134a and flushed all the pag oil out of my 1997 Chevy Express after it ate 2 stock compressors in the first 60,000 miles. I installed compressor 3, an aftermarket sanden built unit, added the recomeended amount of oil in mineral oil, and charged R12 into it, the 85% rule in reverse. It has been running on R12 for over 2 years now and about 60K miles. It BLOWS ICE, even at idle.

Reid Fleming

iTrader: (2)

I run R-406a Autofrost. In hot swampy Houston Texas, It will run 31°F with the fan on the 2nd lowest setting. I got it down to 29.8° running the fan on the lowest setting about a week ago.

Houston and Miami duel it out for highest dew points in the country. Being a FL person, I'm sure you know it's not the heat, it's the humidity. And high duct temps of R-134a on old cars just won't lower the temp far enough below dew point to truly make the car feel dry.

I drove to the park 2 weeks ago. About 5-7 minutes from home. When I got there and shut the car off, I went and looked under the passenger side. There was a continuous non broken stream of water coming out of the evaporator.

That's with the stock low pressure cycling switch settings (off at 26 psi).

The only downside is that it really gives the radiator a run for the money (sending inferno like temps to the condenser).

arrowcamaro

iTrader: (2)

Yup, I've been nothing but pleased with the autofrost. So much for -"They are what they are called and not a long term fix."

DJP87Z28

29.8 deg A/C must have been spitting ice cubes out the vents.

Fast355

iTrader: (2)

and it DOES! Mine will get into the low 30s on a lower fan speed.

Even well into the 90s, the compressor was cycling at idle, with both blower fans on HIGH (dual evaporator system). R12 works GREAT with a R134a style condensor. 39*F from the vents at idle on high fan speed.

Reid Fleming

iTrader: (2)

It will warm up to the mid 30's at stop lights. But on the highway it will sit there at 30-31° on 2nd speed for as long as you want. I drove out to NASA last year (45 minute drive on the highway) to go talk to a window tint guy about getting my car tinted. 5 minute stop. Turned around and drove home. Same 45 minute drive.

Ambient conditions outside were 80°/70%. Ducts blowing 31° on me on 2nd speed the whole way out there and back. About 30 minutes into the return trip home, I switched it to VENT and got a bunch of ice fog blow out the ducts into the cabin. I've only ever had the ice fog happen once. Inside the car, I brought some temp/humidity gauges. Sitting on the seat, they were reading 70°/29%. A world of difference from the 80°/70% outside. That's a 69° dew point outside and a 36° dew point inside.

To get ice fog, you need to run it on the highway well past the point of your body being cold. Hands start to go numb after having freezing air blown on them.

So how can the system blow below freezing air without turning into a block of ice? Simple. The GM R-4 compressors are cycling compressors. When it ices up, the pressures drop. The compressor turns off and doesn't turn back on until it hits the turn on point (47 psi on my car). For the system to get to 47 psi, the ice has to melt. This is usually about a 5-10 second off time on the compressor.

The guy that invented Autofrost made a stronger version of it called GHG-HP back in the early 1990's. It would do 25° duct temps. But cycling compressors were mandatory. Variable displacement compressors (which stay fixed at 28 psi) would ice up. So you either neeeded a defrost timer on a variable compressor or you needed a cycling compressor. Actually you could use a variable compressor without the defrost timer. But you'd need to switch it to VENT about once every 10 minutes on the highway. Ice fog was common when switching to VENT. GHG-HP is not available anywhere anymore. It was a limited run anyways.

Autofrost is
55% R-22 (strong stuff, used in residential A/C)
41% R142b (brings the R-22 pressures down to R-12 levels)
4% R-600 (Isobutane, carries the oil around the system. Uses the same mineral oil as R-12.)

The GHG-HP stuff was 65% R-22. People complained it was too cold and that Autofrost worked great enough. Switching to VENT a few blocks from home was recommended to get the tremendous amounts of moisture off the coil before shutting the car off. I know with my Autofrost, that when I switch to VENT before getting home, it will fog up every gauge in the car. Feels like a greenhouse. But it keeps the coil clean and dry for when you park your car overnight. If I'm just at a grocery store or a mall, I'll leave it on MAX and let it drip. Even blowing the moisture into the car with VENT, it still drips a large, large amount of water onto the ground. Like somebody dumped a 1 gallon container of water underneath the car. It's neat.

The limit for GM cars seems to have been met with the GHG-HP. Anything stronger than that would start bursting the evaporator (too high of pressure) even when you didn't use the A/C. Simply parking a car on a hot day and then allowing the engine to heat soak everything would send the pressures too high.

There is a GM evaporator dryer out on the market that I'm thinking of hooking up. The way it works is if the cabin temp is above 60° (always during the summer) and the battery is above 12.5 volts, when you shut your car off it will wait 30 minutes, then it turns the fan on high speed for 10 seconds. Blows the moisture into the cabin. Then it shuts off for 10 minutes. Then another 10 seconds of high speed fan. It repeats this over the course of an hour. Total fan blowing time is 1 minute (10 seconds per 10 minutes for 60 minutes). This allows you to leave the system on MAX A/C and never worry about moisture building up in the evap. No chance of mold growing this way. Mold tends to be an issue on a lot of R-134a cars. Since they run warmer A/C temps, the coil tends to sweat rather than drip (like on old R-12 cars). Newer cars have tighter clearances around the coil too. A sweating coil won't rinse itself off like a wet coil will. Thus you get mildew and eventually mold. A common problem in humid climates. In theory any vehicle A/C should drip itself dry, just like a house air conditioner. But you've got a small dark wet coil in a confined space surrounded by hot engine and humid hot weather outside. The perfect recipe for mold. I do the VENT before getting home and my A/C still smells wonderful after 20 years.

Here it is: http://www.airsept.com/index.php?loadmod=eed

Exactly. R-134a is more inefficient compared to R-12. That's why newer vehicles have oversized condensers and faster fan speeds. That's also why converting an R-12 car to R-134a doesn't work that well (especially in hot muggy climates). The R-12 condenser is too small and R-134a is a warmer refrigerant. Humidity stays high. Temps are "bearable" but not comfortable.

Should see what it puts out for temp on lower fan speeds. Lower fan speed = colder coil = colder duct temps.

KITT1983

iTrader: (3)

Where can I get this R-406a Autofrost and will it work with my R-134a compressor?

Reid Fleming

iTrader: (2)

www.refrigerantsales.com sells R-406a as well as Cool Top.

R-406a (aka Autofrost) isn't compatible with R-134a systems. It was designed as an R-12 substitute that uses the same mineral oil as R-12.

R134a systems use PAG or POE oil. Cool Top is essentially the R-134a version of Autofrost and as such uses the same PAG or POE oil as R-134a. I haven't used Cool Top, so I can't vouch for it. I also don't know the ingredients in it. However I would guess that it's probably just as good for 134a as Autofrost is for 12. Cool Top comes with a drying agent inside that dissolves moisture inside the system. Still important to vacuum the system thoroughly. If you dig around the website above, you'll find the FAQ section about Cool Top.

If you took an R-134a system and converted it back to R-12 like Fast355, then you could use Autofrost. To do that properly you'd need to hand flush the compressor with mineral oil. Best to replace everything if you went that route.

I must add a warning though. A/C shops won't want to tough your car since it will contaminate their R-12 or R-134a tanks if they're evacuating your system in the future.

transam85dudeman

yesterday my jaw dropped when i found some 12oz cans of R12. i was at a flee market, and some mexican wanted 60 bucks for 4 cans (15bucks a can). considering R12 goes for 60 for 16oz and you gotta have a/c certification here, i thought that was a deal. another dude had ac gauges. i was tempted, but passed.

fazt4life

iTrader: (1)

my camaro when i bought it had no refrigerant in it so i went to pepboys and bought the r-12 to r-134a kit. screw new adapters onto the high and low side, turn on the a/c and hook up the refrigerant to the port, add two cans done and now i have a extremely cold a/c.

oh yeah when i was first charging the system for the first time i have to take the switch on top of the compressor unplug and jump it to 12v to get it to run while i put the refrigerant it. worked like a charm.

Reid Fleming

iTrader: (2)

How long ago did you do this? Sounds like the old oil will be in the system still. Compressors don't like that.

How cold is extremely cold? Have you measured the temps?

dimented24x7

iTrader: (2)

Theres no doubt that the older chlorinated refrigerants where more effient. I used to work at a consulting engineering firm designing HVAC systems for large commercial and industrial applications (retail stores, warehouses, industrial plants, etc) and I started just as many of the companies where starting to phase out the R-22 and switch over to R-410A. Even with initially redesigned condensors and compressors, the same units where experiencing an average drop in capacity and efficiency of 10%. But, in a few years, many of the newer units using the R-410A where exceeding the efficiency and capacity of the older units using the previous chlorinated refrigerant. As time goes on, the engineers seem to be able to adapt to the difference in performance. I know my old accord (new car at the time) with the R-134A A/C was ****. Barely could keep the interior cool at low speeds and blew only semi-cool air in very hot weather. But, the R-134A A/C in my somehwat-new malibu with 100k miles gets down to around 45 degrees or so in hot weather on high at low speeds. Im sure if it was converted to R-12 it would get a lot cooler. But, on the other hand, it was designed to operate well above freezing to allow the system to be used across a wide range in temperatures.

dimented24x7

iTrader: (2)

Last I heard they actually have a GLUT of it now, due to the fact that the market has nose-dived in recent years with the older R-12 cars reaching the end of their life cycles. Spoke to some guy who worked with a distributer, and they where actually selling it for almost the same price as the R-134A to move it.

arrowcamaro

iTrader: (2)

The question now is how long is it going to last? If it leaked out the r12, it will leak out the 134 faster.

What temp is "extremely cold"?

fazt4life

iTrader: (1)

its not extremely cold but its cold enough to the point where it makes driving around good. i haven't measured temps cause who cares. and i also put a can of stop leak in the high side port after i was done to close up any leaks and its been working fine for weeks now.

KITT1983

iTrader: (3)

Thanks Reid Fleming,
I think I will try Cool Top, since I already converted my A/C to
R-134a last year. my A/C went down to 40 degrees

transam85dudeman

i had problems with my a/c one time, i dont know if its still good. check this, when flushing my radiator i turned on the a/c or something? and the whole engine was bouncing up and down. i was like what? so anyways i cut the belt for the compressor, and started it up, worked fine. the compressor would not spin for some reason. i've helped install whole house conversions a/c. and can work on cars, but car a/c work is alien stuff. vacuum this, pump that, mineral oil this, what the f. im going to go pick up an a/c book, but besides that, Y "was" my compressor seized? its been 4 years, and still no belt on A/c compressor, it spins fine now. could it be that a wire crossed on top on the compressor? im so dumb.

Reid Fleming

iTrader: (2)

Keep me up to date on how it works for you. I'm interested in hearing some Cool Top reviews. Been thinking of converting my wife's vehicle to it.

http://www.autofrost.com/autodisc.pdf

I'd recommend printing the pdf file above. Read the whole thing. It's a good intro to vehicle A/C. You won't get it all. But if you read it a 2nd and 3rd time in the future, it will make complete sense.

Now transmissions....those are like brain surgery to me.

1986iroc350

iTrader: (1)

I used the autozone converter kit for about 30 bucks with the pag oil to convert mine to 134a. I had a friend of mine pull a vac. and recharge. works ice cold on the hottest days here in Orlando area of Florida. Couldnt be happier. good luck!

KITT1983

iTrader: (3)

I had to replace my A/C Compressor (due to a burnt A/C clutch general rule of thumb).I went with a New Napa brand A/C compressor with 2 year/26,000 warrenty. I also replaced my orfice tube and actuator for my R-134a conversion. I went to napa for my parts

abray1

freeze 12 is the only way to go. We do not have the correct size condensors and evaporators for 134. Converting them works but it is not as efficient as freeze 12.

Reid Fleming

iTrader: (2)

I'm not sure what the benefit of Freeze 12 is. It's 80% R-134a and 20% R-142b. R-142b is a warmer refrigerant than R-134a is. So how is it supposed to be colder than pure R-134a?

Freeze 12 says no oil change is necessary (leave the mineral oil in). But they also recommend switching to POE for best results.....Well which one is it? I know R-134a does NOT work with mineral oil. And since Freeze 12 is 80% R-134a, the idea of leaving the mineral oil in sounds like a bad idea. Might as well do the complete switch to R-134a if you want to do Freeze 12.
http://www.freeze12.com/convproc.htm


http://www.autofrost.com/oil/
^^^ Comparison of various types of refrigerants in mineral oil. I realize who the company is that did the test. But it does conform to the R-134a + mineral oil = problems waiting to happen. (just check out Freeze 12)

abray1

If you want the best get 414B HOT SHOT. It is expensive but it is compatible and works great. I used to have a can of it but ran out and started using freeze 12 since it comes in the small cans.

Fast355

iTrader: (2)

Hot Shot and Freeze 12 = BAD IDEA

afremont

So the A/C in my car was never anything to brag about. Maybe that's because the o-rings leaked and the car had sat on the lot for nearly a year before I bought it (new in 1990) so it was probably already low on freon. It has never had anything done to it (car has sat for most of its life). How much is it going to cost me to charge it up with autofrost? Other than fixing the o-rings, do I have to do anything else? Can I charge it up myself?

abray1

I hear they are coming out with a butane type refrigerant that is compatible with old R12 systems that is supposed to be as good as R12 but I don't know the number for it yet. It is environmentally friendly and inexpensive but you can't smoke around it.

Reid Fleming

iTrader: (2)

If the o-rings are the only spots you have a leak, then new o-rings and then you should be good to go. You'd need to vacuum out the remaining R-12 (any shop can do this) and check to make sure it holds a vacuum after everything is finished.

Our cars (at least mine does) take 2.25 lbs of R-12 which just happens to coincide with 3 cans of Autofrost exactly. (Autofrost uses 80% of R-12's amount....so 1.8 lbs or 3 cans)

Autofrost goes in as a liquid (small cans held upside down to get liquid). There are a few things to do which are all in their online instructions. I'd suggest printing out their instructions and reading them several times. It's not rocket science, but there are safety aspects (do NOT install in the high side while the car is running.) And certain things related to injecting it. You can't just pump all 3 cans in and then start the car. You'd get a bunch of refrigerant slugging the compressor.

You need an EPA 609 license to buy the stuff. The 609 test is online and fairly easy. It's a valuable read in my opinion.

Do a search on my username and R-406a or autofrost. You'll probably get some good reading material.