I hope this hasn't been discussed before: (if it was, please forgive me and point me to the right threads.)

In the last couple weeks I saw "conversion kits" at Wal*Mart and Autozone/Kragen to refill and convert R-12 A/C to R-134. They sell for about $30 + a little extra for a connector conversion kit. I've seen 2 different brands, but have a feeling they are two different types offered by the same manufacturer.

Does anybody have any experience with this? Does it work, or does it destroy even more? One brand working better than the other? Is there a specific one I need? At this point my A/C is blowing hot air/ambient air, so I'm guessing it's empty. (I live in a climate where A/C is only an issue on a handful of days, so I went for months without even knowing if my A/C is working, so it never came up before. (on my other cars it's more of a glorified dehumidifier/window defrost switch ) :P

they don't come with the rings, and you will need more cans of r134a. the o-rings should be replaced when converting to r-134a; something to do with the ester oil. you will also want to replace your orifice tube, to one of the adjustable deals.

there are other problems with r134a conversions, but not anything we can do much about. its not as efficient, and the r12 compressors aren't designed for the smaller molecule which means they work harder, in effect shortening the life of your compressor. r134a slowly leaks throw the r12 "rubber" lines. so in effect you will wind up filling even a perfect r12 system more often, and the replacing the compressors more often.

upshot is, you should at least consider replacing the o-rings, and orifice tube. there is not much you can do for the rest. i filled using one container of the stop leak stuff, hoping to prevent/slow leaks(maybe just to assuage my mind, though)

[This message has been edited by JMunilla87GT (edited 07-18-2007).]

One. Running that stuff through a system built for/previously filled with R12 will cause a buttload of problems.

Two. Your system is already broken, probably due to leaking. Filling a leaking system with something that leaks even better means that you probably won't have AC for very long.

quote Originally posted by Austrian Import: I hope this hasn't been discussed before: (if it was, please forgive me and point me to the right threads.) In the last couple weeks I saw "conversion kits" at Wal*Mart and Autozone/Kragen to refill and convert R-12 A/C to R-134. They sell for about $30 + a little extra for a connector conversion kit. I've seen 2 different brands, but have a feeling they are two different types offered by the same manufacturer. Does anybody have any experience with this? Does it work, or does it destroy even more? One brand working better than the other? Is there a specific one I need? At this point my A/C is blowing hot air/ambient air, so I'm guessing it's empty. (I live in a climate where A/C is only an issue on a handful of days, so I went for months without even knowing if my A/C is working, so it never came up before. (on my other cars it's more of a glorified dehumidifier/window defrost switch ) :P

How long would you like your AC to last? One of those kits might give you a working AC system that lasts for a couple of years - or (more likely) you'll have one that sorta works for a little while then suffers a catastrophic (and very expensive to repair) failure.

You should come visit me one day soon - I can run a couple of tests on your AC system and find out where it's at now and what it would take to make it work reliably. It's quite likely that all it needs is a "whiff" of R12 to put it back into good operating condition.

But if you want to convert to R134 - beware. The AC compressor in your car is NOT compatible with R134A - it's not designed to withstand the higher pressures generated in a 134 sytem and may self-destruct in short order. Also, the dessicant bag inside the accumulator is not compatible with 134; it'll "dissolve" and release the dessicant into the system - so if the higher pressure doesn't kill the compressor, the dessicant granules will do it in. Even if your car has a newer (compatible) accumulator and the AC compressor doesn't chew itself up - the R134 molecule is much smaller than the R12 molecule. It'll seep through the o-rings at the pipe connections and the walls of the hoses slowly and you'll need to recharge yearly - or replace those parts.

Can you buy one of those Wal-Mart conversion kits, use it and have cold air come out of the vents? Yup. Will it last? Nope.

If the AC system has major problems and you have to disconnect lines to replace components - then taking the extra steps to do a proper conversion to R134A would be appropriate. But if your system is intact and just needs to have the freon charge replenished then you're much better served by keeping the system on R12. It'd be cheaper (to do it right), work better, and last much, much longer. Years longer.

Let me give you a success story...

When I bought my GT 5 years ago the owner said the a/c worked just fine, only needed to be filled. I'm thinking yeah right.

Since I had nothing to lose I bought the $30 kit, and screwed on the fittings and starting filling it with R134a...to my amazement, the compressor sprung to life, amidst screaches and growns and smoke, but cool air starting coming from the vents.

That was 5 years ago and the system still has a small leak, but about once a year I hit it with a can of R134a and I have between 45F and 50F at the air outlets.

I also wanted to add that I live in Texas where the a/c gets used a LOT. I practically never turn it off year round.

And also, I went the other way on my coupe and paid $1500 for a professional conversion, and got much worse results, the system leaked down almost immediately, and I was charged for a compressor replacement, which I likely didn't need, since my system still leaks like crazy.

[This message has been edited by jscott1 (edited 07-18-2007).]

Thats pretty good for 134. 2 of my new cars have 134 from the factory of course, and on a 90* day its lucky to be 70-75* coming out the vents. Ive never been a big fan of 134. I call it cool air as opposed to cold air on old R12 cars.

I forgot to mention the different compressors used in Fieros; this is important.

V6 Fieros came with the DA-6 compressor (not 134 compatible) until a mid-year change in 1987 when they switched to the HR-6 compressor. The HR-6 compressor can handle R134 just fine, so late 1987 and 1988 Fieros can convert to R134 without compressor problems. They also switched to a compatible accumulator during production but there's no way to tell when that happened; accumulators don't have model / serial numbers.

As a "general rule" 1988 V6 Fieros are a safe conversion to R134A. Earlier models are more troublesome.

Earlier cars with the DA-6 compressor - converting them to 134 is a gamble. Sometimes it works, sometimes the compressor self-destructs and sends metal shavings all through the system. Our Austrian friend is driving a 1986 Fiero, so he needs to understand the risks. If his system is intact but has just leaked down to the point where the low pressure switch prevents the compressor from running - a pound or maybe a pound and a half of R12 is all it'd need to be working perfectly again.

quote Originally posted by Whuffo: I forgot to mention the different compressors used in Fieros; this is important. V6 Fieros came with the DA-6 compressor (not 134 compatible) until a mid-year change in 1987 when they switched to the HR-6 compressor. The HR-6 compressor can handle R134 just fine, so late 1987 and 1988 Fieros can convert to R134 without compressor problems. They also switched to a compatible accumulator during production but there's no way to tell when that happened; accumulators don't have model / serial numbers. As a "general rule" 1988 V6 Fieros are a safe conversion to R134A. Earlier models are more troublesome. Earlier cars with the DA-6 compressor - converting them to 134 is a gamble. Sometimes it works, sometimes the compressor self-destructs and sends metal shavings all through the system. Our Austrian friend is driving a 1986 Fiero, so he needs to understand the risks. If his system is intact but has just leaked down to the point where the low pressure switch prevents the compressor from running - a pound or maybe a pound and a half of R12 is all it'd need to be working perfectly again.

might be why i never had a problem with my conversion. would a new accumulator from the autoparts most likely be compatible? i would think so, i doubt they would keep the older version around. anyone know for sure?

quote Originally posted by Whuffo: As a "general rule" 1988 V6 Fieros are a safe conversion to R134A. Earlier models are more troublesome.

Forgot to mention My GT is an 88 so that's probably why I got lucky.

If you buy a remanufactured compressor, it should be rebuilt with R134a compatible seals though.

Whuffo, so if I understand you correctly, I should stay away from the Wal*Mart conversion. Kind of was my initial guess. Even though it says "safe for r-12 systems", correct?

Don't worry, before I do anything, I'll see you about a diagnosis and possible solutions. Other than installing an A/C system in the house in Austria, I know nothing about A/C. Like I said before, in Monterey, A/C is more of a glorified "window defrost button" and the "360 air conditioning" is adequate most of the year. ("360 air conditioning = 3 windows open, 60 miles an hour. ) Besides I first have to fix the problem of my Fiero being a "hybrid".

Since it get's thrown around, and I'm not afraid to ask stupid questions, what exactly is r-12, and r-134. Is r-12 Freon based and therefore phased out, or is that a third animal? Is r-12 still available?

FREON is a registrered trademark of the DuPont corporation for a type of refrigerant. The type in cars was known as Freon-12. The chemical name was Dichlorodifluoromethane. If it's made by another vendor it's generally just called R-12

Other types of refrigerants are just different combinations of chemicals. R-134a is 1,1,1,2-Tetrafluoroethane. There are many others.

quote Originally posted by Austrian Import: ... what exactly is r-12, and r-134. Is r-12 Freon based and therefore phased out, or is that a third animal? Is r-12 still available?

R12 and R134a are both chemical refrigerants. "Freon" is a DuPont trade name applied to a variety of refrigerants they manufacture.

Because it contains chlorine, R12 damages the stratospheric ozone layer, so its use was phased out by international agreement in the early '90s. R12 has been illegal to manufacture or import into the U.S. since 1993, but stockpiles of R12 manufactured before 1993 and reclaimed (recycled) R12 are legal and still available ... at a price.

R134a does not damage the ozone layer, and it was chosen by most manufacturers as the "closest" replacement for R12, due to its similar physical and thermodynamic properties. R134a is incompatible with the mineral oil used in R12 systems, as well as most of the desiccants (drying agents) used in older R12 systems, so those need to be replaced when converting to R134a.

Despite what you may hear or see on the Internet, there is no such thing as a legal "drop in" replacement for R12.

[This message has been edited by Marvin McInnis (edited 06-24-2008).]

They do make it sound easier than it is don't they? When you turn on the AC does the compressor come on at all? If not, depress the schrader valve on the accumlator for a second and see if there is any pressure left. If not them the system has either a serious leak or someone has vented/removed the refrigerant. If this is the case there is so little refrigerant remaining if any that it's OK to open the system and repair it. This will actually make it easier to convert.

If you actually do attempt this try and do everything in one day. If you walk away for anything over a couple hours I would plug up all opened lines, etc with lint free cloth soaked in refrigerant oil to maintain some sort of a moisture barrier.

Can you turn the front plate of the compressor by hand (1/2 turn is fine)? If not it needs to removed and repaired or replaced.

To the job right you'll need a manifold set, a vacuum pump, a set of O-rings and an air compressor. I think the air powered vacuum pumps are sufficient (others may chime in otherwise) they'll pull between 28 and 29 inches of vacuum with most air compressors. You need to get a new accumulator and I would recommend a new orifice tube.

If your orifice tube is very dirty or clogged up I would recommend just stopping right there unless you want to replace or remove and clean out every component and line.

Assuming it looks pretty clean disconnect the AC compressor lines from the compressor. Now with your air compressor either get some flush and and a flushing nozzle or just use air and blow into the compressor inlet and through both lines. You should get a fair amount of oil out the other end of each line (at the accumulator) and the exhaust of the compressor so be prepared and have something collect it and PROTECT YOUR EYES! It should be pretty clean and oily. The more oil you get out the better, for two reasons. The most important reason is that means there was a good quantity of oil remaining and increases the likelyhood that the compressor is OK. The second reason is you want to replace as much oil as possible, volume wise, with 134a compatible ester oil (PAG oil is completely incompatable with any remaining mineral oil according to the manufacturers). I'd get ester oil with the florescent dye to help detect leaks.

If you do use a flushing agent make sure you remove as much as possible and don't do the rubber lines too long. The existing oil in the system has built up a barrier to keep the 134a from leaking through the rubber.

Replace the oil in the compressor and the lines, I use a turkey baster, the o-rings (coat them with oil first) and reassemble with your new accumulator.

You can now add the 134a adapters but I would recommend removing the locktite before doing so. From my experience the single most common source of leaks is the high pressure schrader valve ( which a vaccum test is not going to notice) and once the locktite has set on that adapter it ain't coming off to replace the valve. The aluminum connector will shear off before the adapter will come loose. Now with your manifold set and vacuum pump pull a vacuum until the gauge stabilizes and close the manifold valves before shutting off the vacuum pump. DO NOT disconnect the manifold set.

Let it sit at least 30 minutes.

If it's still above 25 bring it back down to 28 or more and repeat. If it's less than 25 then it's probably much less and you need to find and fix the leak.

When it remains greater than 28 for more than 30 minutes your ready to add one can of refrigerant. Connect the adapter with the refrigerant can to the supply line of the manifold and puncture the can. Then loosen the supply line at the manifold a bit for a second to purge the air in the supply line and replace it with refrigerant. You can now open the low side valve to admit refrigerant to the accumulator. DO NOT OPEN THE HIGH SIDE VALVE! IF you do it with the can inverted you'll be able to get more refrigerant in until the pressures equalize, probably at 40-60 PSI (read on both gauges).

Now you can open both windows, turn on the car, the AC and put the fan on high. The compressor should start cycling on and off. If you watch the pressure gauges you'll see it shut off at ~28 PSI and back on at ~48 PSI. If the compressor doesn't cycle you have more problems, either electrical or with the compressor clutch so there is no sense in going any further with adding refrigerant until whatever else is wrong is rectified. Otherwise,

When the low side pressure is at ~28 shut off the low side valve and remove and replace the can with a second can of refrigerant. Add the second can and the compressor should stay on continuously or it may cycle off a little. The air coming out the vents should be very noticably colder than ambient (~18-20 degrees).

A full charge of R-12 for a Fiero is 40oz. I believe a full charge of 134a is 10% less so 36oz. That would be 3 12oz cans. A couple ounces undercharge is better than an overcharge so if you have 14 oz cans then 3 cans is too much. If it doesn't cycle off with two 14 oz cans I would leave it at two. A little less cooling capacity (the more noticable the hotter it is) but much less wear and tear on the AC system.

[This message has been edited by Fierari (edited 07-18-2007).]

I didn't have a problem with my conversion after the compressor locked up under the R12 system. I did a basic install with an orifice tube change on my 86, and the conversion ran without much of a problem for about 4 yrs until an accident put part of my muffler in contact with one of the lines causing a leak. One thing I did notice throughout with 134 use in the Fiero and new cars that came equiped with it, it doesn't cool as well as R12 and maybe a custom larger condenser or better cooling of it would help with that, or an additional condenser in series for more cooling between cycles.

Then again part of my cabin heat is the result of my unwhittingly removing a good bit of the insullation from the firewall.

[This message has been edited by Joseph Upson (edited 07-18-2007).]

Well heres my question, I bought my '85 SE V6 a while back and have been slowly working to restore it. Like many cheap Fieros, the AC doesnt work in the car, where should I begin looking to diagnose the problem? Ive been reading most of the posts from this thread because it applies to me as well, my car probabily has a leak and even if I could buy enough R12 to refill the system, I wouldn't want to risk it all leaking out. So if I was going to charge my system with R134 I would need the new rings and orfice tube, but should I also be on the lookout in a junk yard for an '88 for a compressor and accumulator? I just don't know where to start with this problem and now I really don'y want to fill my system with R134 to just have my compressor blow up. In FL the AC is a big deal...

Thanx - Dan

quote Originally posted by rogergarrison: Thats pretty good for 134. 2 of my new cars have 134 from the factory of course, and on a 90* day its lucky to be 70-75* coming out the vents. Ive never been a big fan of 134. I call it cool air as opposed to cold air on old R12 cars.

Roger, I'd be taking them cars back, and getting them fixed then.
My '02 Venture, was blowing 38 degrees out the vents today, and it was 93 outside. My wives '03 Impalla will freeze you out of the car also, any given/hot, day but I don't have the temp to give you, as I don't keep a thermo in the vent, like I do the van.
I've converted my Indy over to R134, replacing the compressor, tube, accumulator, and o-rings, and it will get below 40 degrees out the vents, no problem.
My 78 Z-28 I converted also, to R134, using the old compressor, new acculumator, new condensor, ford blue orifice tube, and new o-rings. 40 to 45 degrees is not a problem for it either. Both Indy and Camaro were tested on 85 degree plus days.
I can't believe that I am just that lucky. I here a lot of people having problems with R134, but mine all work just fine.

Kevin

quote Originally posted by jscott1: Forgot to mention My GT is an 88 so that's probably why I got lucky. If you buy a remanufactured compressor, it should be rebuilt with R134a compatible seals though.

It's not the seals that's the problem with the DA-6. That compressor has aluminum cylinder bores; they're just not strong enough to keep the piston straight at the higher pressure levels. As the pistons "**** " in the cylinders aluminum shavings get into the system; when a piston tilts far enough to jam, the compressor locks up.

The HR-6 compressor has cast iron cylinder bores - much stronger. Accept no substitutes....

Edit to add - the forum converted a word that means for something to tilt out of plumb. Think male chicken...

[This message has been edited by Whuffo (edited 07-18-2007).]

I have an 87 se with a 2.8. how could I tell if my car has the 134 friendly compressor or not?

I got a question for you guys, I noticed while taking the top end apart on the 87 fiero I just got last month that there is no belt on the A/C compressor, what should I assume/do to see if the system works or not? Thanks

quote Originally posted by pontiacking: I got a question for you guys, I noticed while taking the top end apart on the 87 fiero I just got last month that there is no belt on the A/C compressor, what should I assume/do to see if the system works or not? Thanks

If you see no belt on the a/c compressor, you should assume that it's toast.

Fierari - thanks for that step by step. It was awesome.

alright, thats what i figured. how should i go about restoring the a/c system? average cost?

I have done well over 100 R-12 to R-134a conversions at our shop. The only ones who have come back are those that had a bad system to start with. As far as O-rings and molecule size, don't believe the hype. Most of the systems that any O-ring failure happens with is due to shrinkage. Use the kit with the gauge and oil and you should enjoy years of trouble free service. The kit with the oil will usually lube your o-rings and make them seat again. Once again however, most of the comebacks have had a bad compressor, dryer, or a rotted evap. 2 years ago they wanted to charge my mom $700 to convert her A/C. I told her what to buy and do (she lives in FL and is 78 y/o). She is still enjoying the fruits of her labor right now. Don't believe the hype, I deal with people coming in my shop everyday who have been told that thier vehicle is going to crash and burn if they don't replace this or that. My fiancee (whom I live with) had to go to get tires on her car (we don't do tires). She came back hysterical because they convinced her that her CV boot was bad and she had to get it replaced within 8 hours or it would cause her to wreck. She was getting the new tires for a trip to FL. The had poked a hole with a knife in the boot and smeared some grease on it and spun it up to sling the grease. Luckily the guy was "not there" when I showed up to "give him my $0.02". Oh, and BTW, the O-rings are made of basically the same material for BOTH systems. Parting shot, get the Wal-Mart special with oil and gauge and try it out. What do you have to lose? $50 vs. $300 or more?

------------------
carpe diem

quote Originally posted by frankenfiero1: get the Wal-Mart special with oil and gauge and try it out. What do you have to lose? $50 vs. $300 or more?

That's what I did and it worked.

If you walk in an a/c shop with a 20 year old car and tell them to fix your a/c you will hear "$CHA-CHING" as they rack up a bill for well over $1,000 and all they basically do is screw on the fittings and fill the system with R-134a

i paid 19 bucks for a fill thingy at wallmart, put it in and it blew awesomely cold air!

------------------

Had the same results as Jscott on my 86. All I did was toss the Wal-Mart kit on and filled it up. The main shaft seal on the compressor finally went after 4 years, but it was 19 years old. I doubt the 134a caused that.

We use the A/C a lot here, too.

------------------
1986 SE 350 V8

quote Originally posted by pontiacking: I noticed ... that there is no belt on the A/C compressor, what should I assume/do to see if the system works or not?

The previous owner may indeed have removed the belt because the compressor was seized, but there are several other possible explanations. It may have a noisy (failing) pulley/clutch bearing, a bad clutch, noise from a slipping belt, or the system may have just stopped cooling and the owner didn't want to deal with it.

The first step is to determine whether the compressor is seized or not, You can check this pretty easily. There is a nut on the pulley/clutch end of the compressor shaft that you can use to turn it. If the shaft turns fairly easily, the compressor is not seized, although it could still have other internal problems.

I cant ever remember being in a newer car that I thought was truely cold. My Magnum, a friends Magnum and a couple of other with Chargers are all the same. My Lumina APV van, and both my Caravans were the same. If its HOT out, they have to run on recirculate and full speed to keep it cool. My Fieros, Corvettes amd Mercedes with R12 could be turned down to low after a few minutes and it was VERY cold air at the ducts. The Ferrari kept blowing so cold, I could keep a can of pop in the cup holder for hours in front of the vent and keep it cold. My vette convertible was R12 and kept very cool, dealer swapped it over to 134 after fixing a small leak and its OK, but not nearly as cold as it was.

add. just got finished with one of the girls new Scion XB. It was wrecked in the front but not very bad. It did bend an AC hard line, but pulled it back out. I ran the AC in it to make sure there were no leaks in the line or condenser and had the dealer check it. Full on, its cool...but definately not cold, and dealer said its fine. I guess my body just cant feel cold or something with old age. But it does kick in from nostalgia since old cars seem ice cold.

[This message has been edited by rogergarrison (edited 07-19-2007).]

Thanks for all the tips. They're really helpful. Can't wait to get started on this project sometime in the next 2 weeks...

quote Originally posted by rogergarrison: I cant ever remember being in a newer car that I thought was truely cold. My Magnum, a friends Magnum and a couple of other with Chargers are all the same. My Lumina APV van, and both my Caravans were the same. If its HOT out, they have to run on recirculate and full speed to keep it cool. My Fieros, Corvettes amd Mercedes with R12 could be turned down to low after a few minutes and it was VERY cold air at the ducts. The Ferrari kept blowing so cold, I could keep a can of pop in the cup holder for hours in front of the vent and keep it cold. My vette convertible was R12 and kept very cool, dealer swapped it over to 134 after fixing a small leak and its OK, but not nearly as cold as it was. ...

My '05 Magnum blows very cold air even in the GA humidity. I think the humidity today was somewhere around 350% and it only took a few minutes to bring the cabin from 110 to 65.

Wow, so much disinformation. The closed-system conversions, i.e. "Wal-Mart conversion kits", are EPA approved and recommended, the EPA repealed their previous recommendations of o-ring/seal replacements along with dryer/accumulator and condensor replacements to convert over to R134a. They used to believe that the drying agents in the R12 accumulators were not compatible with R134, they also used to believe you could not/should not inject R134a into a filled R12 system. Both of those trains of thought have been reversed by the EPA. R134a may be used as a flushing agent for R12 and the drying agents in the R12 accumulators are 100% compatible with R134a.

For those who say R134a can't cool as well as R12 in a conversion just didn't do it right. Factory Air and Visteon offer replacement valves for R12 compressors to make them optimal for R134a use, they also supply the appropriate pressure switches. The key to colder air, faster, is in the orifice tube, they sell automatic adjusting orifice tubes for climates both below and above 105-degrees Farenheit. We used to do the unnecessary, "complete" conversions for customers at my old shop, the ones costing them $700 to $900 and they got the same performance that $36 Wal-Mart kit gives you. When the EPA reversed their decision on conversions, we used the quick-change adapters, flush out their A/C system and toss in an adjusting orifice tube and oh my.. you could hang meat in these cars. How much did it cost for this, $90 to $140 at most depending on the vehicle.

quote Originally posted by LT-5Fiero: Wow, so much disinformation. ... R134a may be used as a flushing agent for R12 and the drying agents in the R12 accumulators are 100% compatible with R134a. ... they also used to believe you could not/should not inject R134a into a filled R12 system.

"Wow, so much disinformation." Indeed.

It is illegal to vent R134a to the atmosphere, which kinda' rules out using it as a flushing agent ... which I hadn't ever heard before anyway. (Other refrigerants, such as R11, used to be approved by the EPA for use as solvents and/or flushing agents, but not any more.) The XH-7 and XH-9 desiccants used in accumulators manufactured since the early 1990s are indeed compatible with R134a, but many of those manufactured through the 1980s used XH-5, which is not. Desiccant compatibility in original-equipment Fiero accumulators is a big unknown. A new accumulator is about $40; the cost (parts and labor) of a ruptured dessicant bag will approach $1000. It's your money, and your decision.

The EPA still prohibits mixing R12 and R134a. Recovered refrigerant that contains more than 5% of other substances (including another refrigerant) must be disposed of by a licensed facility ... at substantial cost. Even if it were legal, R12 and R134a are different enough (both physically and thermodynamically) that the cooling performance will be unacceptable. 'Nuff said.

When in doubt check the EPA web site for authoritative information.

[This message has been edited by Marvin McInnis (edited 07-21-2007).]

I used one on my 86 se back in the late 90's and its is still working off the same compressor

quote Originally posted by Marvin McInnis: "Wow, so much disinformation." Indeed.

Wow, thanks for that link...much of what has been quoted for retrofits the past 15 years has now been reversed by the EPA... flushing not required, complete oil removal unnecessary, Hoses don't have to be replaced, replacement of o-rings not required, compressor chageout unncecesary... It would appear that the EPA agrees, you can buy a Wal-mart kit and just shoot it in.

[This message has been edited by jscott1 (edited 07-21-2007).]

quote Originally posted by jscott1: It would appear that the EPA agrees ...

Just remember that the EPA is primarily concerned with protecting the environment, not your car.

Actually, the current EPA recommendations are for the most part based on the automobile manufacturers' service and retrofit experience over the past 15 years. For example, while it is true that new rubber hoses are somewhat permeable to R134a, old rubber hoses that have been exposed to refrigerant oil are not. Same for O-rings. (FWIW, my '88 Fiero came from the factory equipped with the newer, barrier-style hoses.) And while residual mineral oil can't contribute to compressor lubrication in an R134a system, it apparently doesn't hurt anything, either; it just migrates to the low points of the A/C system and takes up space.

Like many things in life, you need to gather all the information you can (preferably from authoritative sources) concerning an A/C system retrofit, and then make up your own mind.

[This message has been edited by Marvin McInnis (edited 07-21-2007).]

quote Originally posted by Marvin McInnis: And while residual mineral oil can't contribute to compressor lubrication in an R134a system, it apparently doesn't hurt anything, either; it just migrates to the low points of the A/C system and takes up space.

They said that too. While you wouldn't want to take brand new parts designed for R12 and fill it with R134a, the retrofit experience is that the old oil actually protects the hoses and seals from damage or leakage of the R134a.

So the overall retrofit experience has been better than expected. But I will agree with Roger than most a/c systems even from the factory are barely adequate. I live in Hot and huid Houston where a/c is not a luxury it's a necessity. And even after a new car has been sitting in the sun all day and it's about 140F inside the car, I hate these systems that take forever to cool down. I want ice coming out of the vents immediately.

We had a tech who used to use the recycling machine and flush it out with R134a, then vacuum down and do the necessary conversion and recharge. 4 1/2 years while I was there, he has been there over 15 years now, doing as many as 5 conversions a day during the spring and summer months, never a single comeback from a ruptured bag or anything tied to the conversion itself.

Fairly safe to say that the odds against a bag rupturing because of R134a are pretty slim to none seeing how many people have converted using the closed-system conversion kits and I don't see anyone squawking in here about how R134a destroyed their air conditioner.

We did 1970s and 1980s vehicle conversions all the time at our shop, not a single bag ruptured.

Don't get me wrong, I am a complete advocate on dryer replacements with every A/C service. Any A/C repair I sell customers include the dryer, orifice tube/expansion valve and appropriate oil even though the time they will have the A/C system open, it more than likely won't become contaminated with moisture. However opening up the A/C system and replacing the dryer defeats the entire purpose of the closed-system conversion.

Want ice coming out of the vents immediately? Do what I said, replace the orifice tube with an automatic adjusting one for extreme climates. Alot of new vehicles come with them from the factory, which is why some new vehicles you get in, you have ice coming out of the vents at idle. An adjusting orifice tube allows for superior low speed cooling. I researched it today and got it exact, Factory Air makes an R134a control valve for the V5 compressors found on the 85/86+ Iron Duke Fieros. I don't know if this implies the compressor used on the V6s utilizes a control valve that is optimal for both or not. In the illustrated guide, I couldn't see any physical differences between the V5 compressor and the compressor on the V6s.

Whatever you do, avoid the crap R134 marketing of these products like Big Chill or Artic Freeze or anything that states, "Delivers colder air 25% or 50% faster". That job is up to the orifice tube, the formula of R134a can't exactly do anything about that.