Surprise on my 1990- AC question ??

Hi,

I notice today that when I put my AC on, that the clutch on the compressor did not engage. So, I got out my FM and went through the steps. I applied 12v to the compressor, and it went on, then when I bypassed the condensor connector it went on. So I assume that is because I don't have enough or any charge in my system? Or is this sensor bad? I know it worked last year, and the only thing I did since is replace the radiator, hoses, pump and stuff. So, I guess I need a recharge. I did notice a sticker in the engine area that says the AC has been converted to a R12? Not sure what that is.

Any ideas or advice is greatly appriceatied,
Bob

r12 is the refrigerant. it is not avaliable for purchase anymore due to environmental effects. Most vehicles now are converted to 134 from r12.

Good Luck.

Jess said:

r12 is the refrigerant. it is not avaliable for purchase anymore due to environmental effects. Most vehicles now are converted to 134 from r12.

Good Luck.

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Actually surplus and recycled R-12 is still readily available even on Ebay.

I don't get the "Converted to R-12". Converted from what? Wasn't R-12 still the standard fill in 1990?

To answer your question, you probably have a leak and lost the refrigerant. If so the leak needs to be found and fixed first. Most likely the rubber hoses are going bad.

Ecomike said:

Actually surplus and recycled R-12 is still readily available even on Ebay.

I don't get the "Converted to R-12". Converted from what? Wasn't R-12 still the standard fill in 1990?

To answer your question, you probably have a leak and lost the refrigerant. If so the leak needs to be found and fixed first. Most likely the rubber hoses are going bad.

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I think he meant "converted from R-12."

The conversion to HCF-134a/R-124a is fairly simple - I've done a couple. You do need access to an A/C shop for two steps tho - having the system purged of R-12 (which is recycled,) and having a vacuum pulled on the system after you've put it back together.

Do not simply recharge with R-134a - the oils are incompatible, and you'll wreck your compressor in fairly short order...

If you decide to convert, you'll need to have the system "drawn down" to vacuum (to purge the R-12) and flushed (to get rid of the R-12 oil; ) then change the accumulator/receiver-dryer (that cannister under the compressor; ) then go back to the shop and have them flush out the system and draw it down to vacuum so you can charge it.

Flushing the system is mandatory - if you don't, you'll wreck your compressor in short order. Flushing the system will get the old oil freed up as well, and you do it before you change the accumulator/receiver-dryer, since there is desiccant in there that will soak up the R-12 oil anyhow (and you can't get rid of that.)

This would be a good time to check your compressor oil fill level as well - but that didn't change. Only the system oil (that gets mixed with the refrigerant) changed - and mixing the two makes them sort of "plastic" - they'll gunk up pretty much everything.

If your compressor is heading south on you anyhow, this would be a good time to change it - since R-134a runs a higher "head pressure" in the system, and a backyard conversion tends to result on a blown compressor head gasket. The Sanden SD505/SD507 has, I believe, R-134a type-rated versions available as well.

And to add to what 5-90 already stated, -a good majority of "DIY" 134 conversions allow the introduction of too much oil into the system causing compressor failure (due to hydrolock). Like 5-90 said, -nevermind the fact that the oils are totally incompatible.

I know an A/C guy, and he said "forget everything you read on the cans stating full compatibility with R-12 oil, -it just ain't so"

Everything 5-90 stated is spot-on. Have a full evac done on the system and change out the dryer, -OR, get the leaks in your system repaired and stay with R-12. R-12 IS still available, and many shops still charge with R-12, -but be forewarned, the stuff ain't cheap. All currently sourced R-12 is recycled (since it can no longer be manufactured anymore).

Don't even get me going on the whole refrigerant conspiracy (the banning of R-12), 5-90, I'm sure you know exactly what I'm talking about.

5-90 said:

I think he meant "converted from R-12."

The conversion to HCF-134a/R-124a is fairly simple - I've done a couple. You do need access to an A/C shop for two steps tho - having the system purged of R-12 (which is recycled,) and having a vacuum pulled on the system after you've put it back together.

Do not simply recharge with R-134a - the oils are incompatible, and you'll wreck your compressor in fairly short order...

If you decide to convert, you'll need to have the system "drawn down" to vacuum (to purge the R-12) and flushed (to get rid of the R-12 oil; ) then change the accumulator/receiver-dryer (that cannister under the compressor; ) then go back to the shop and have them flush out the system and draw it down to vacuum so you can charge it.

Flushing the system is mandatory - if you don't, you'll wreck your compressor in short order. Flushing the system will get the old oil freed up as well, and you do it before you change the accumulator/receiver-dryer, since there is desiccant in there that will soak up the R-12 oil anyhow (and you can't get rid of that.)

This would be a good time to check your compressor oil fill level as well - but that didn't change. Only the system oil (that gets mixed with the refrigerant) changed - and mixing the two makes them sort of "plastic" - they'll gunk up pretty much everything.

If your compressor is heading south on you anyhow, this would be a good time to change it - since R-134a runs a higher "head pressure" in the system, and a backyard conversion tends to result on a blown compressor head gasket. The Sanden SD505/SD507 has, I believe, R-134a type-rated versions available as well.

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5-90,

But if it was converted to R-134-a, it would already be R-134a? In which case all he needs is R-134-a added and a leak test and leak fix done.

Where did you hear that R-12 had a different "system" oil from the "compressor" oil that needed to be flushed before switching to 134-a?

The R-12 oil is the same through out the entire A/C system and compressor. It is all mineral oil. Same stuff.

There are two different R-134-a oil types available. One of them is fully compatible with the old R-12 mineral oil (the other is not). I, and millions of others have run the R-134a with some of the old R-12 mineral oil (no flushing in other words) still in the system with no problems. The trick is figuring out how much of the new R-134-a oil to add which depends on how much of the old oil is still in the system.

If all the mineral oil is still in his system he does need to get most of it out, except for the oil in the compressor, but only to make room for the 134-a oil and liquified refrigerant in the condenser/receiver/drier. Then he needs to add less R-134a oil, just enough for everthing but the compressor. Compatibilty is not the problem (if he uses PAO oil, PAO = Poly Aline Glycol), too much oil in the entire system is the real problem.

What they do not tell everyone is that it probably takes at least a 50/50 mix of the two oils to get enough PAO oil in the system to get the remaining mineral oil to flow properly. The R-134a is soluble in the PAO oil but not the mineral oil (thus the initial problem) but the PAO oil is soluble in the Mineral oil (and visa versus). So if you add enough PAO oil and drain enough mineral oil to get a good 50/50 mix at the right volume, there is no problem.

Conventional wisdom is that 1/3 of the R-12 oil is in the compressor and another 1/3 is in the condensor just before the accumulator/dryer. So it probably makes more sense to flush and drain the condensor since the mineral oil left in it is just robbing the system of room for liquified R-134a and thus reducing the condensors capacity and requiring one to add too much PAO to reach the 50/50 blend, and thus ovefilling the system with oil.

I have not heard of blown compressors from too much oil (with in reason that is)! Sounds like an urban legand to me! I have heard of blown compressors from trash like decomposing hoses, poor condenser cooling resulting in excesive head presure, too much refrigerant causing too much head pressure, water vapor freezing and forming ice that blocked the expansion valve where open systems were not properly vacuum evacuated and the refrigerant got low.....

The problems I did have with my second conversion were that the compressor seal was old and worn on my old A/C compressor already and the R-134a is much harder to seal even in new systems. So I was loosing about 12 oz a month of R-134a towards the end of the second year. I finally got a good deal on a new R-134-a rated (had R-134-a seals) compressor and replaced it.

One real no-no is using the old R-12 A/C rubber hoses and connector o'ring seals with R-134a. The old hoses and o'ring seals at all the connections also need to be replaced with the new R-134-a compatable material. (I think it is Viton, not sure).

What 5-90 said out gunking up things is correct if you use the wrong R-134a oil. Do not use the Ester oil!!!!!!!

Ditto on changing the accumulator/receiver dryer, a must if he opens the system up and replaces the hoses (which I recommend).

Lastly, if you live in a temperate climate, like I do, 100% humidity, 120 F cool summer nights (LOL), the R-134-a does not cool quite as well as the R-12. It can cool as well if you increase the condenser and compressor capacity (which is rarely done). So you might consider staying with the R-12 if you live in the tropics.

And the R-12 ban was not a conspiracy guys! :laugh: It was just good business for Dupont whose patents had finally run out on R-12!

OK,

So I ran outside, and check the sticker again. It says "Freeze R12" on the crossmember for the radiator. I looked at the compressor it self, and it has a R12 sticker on it too. There are some strange ( to me anyway) fittings on top of the compressor. On my old 240z, there was only two fittings, in which to deal with. This one appears to have four, two on each line. Is there a visual way to see if this has been changed? I guess I need to look through my FSM to get another view of this.

I was thinking of bypassing the Condenssor Switch and see if it blows cool air. Any issues with doing that? Are those switches pretty reliable? It worked great last year and I think the PO did very little to it, so I don't he recharged before I got it. I guess the other thought is to take it to a AC place and have them check it. Any idea what that might run?

Thanks again for all the input.

Bob:rof:

Ah - everytime I'd seen a reference to AC systems (like in the FSM,) they called it "compressor oil" - so I'd thought it was different from the oil mixed in the refrigerant. My apologies for any confusion - at least I've been corrected now...

If it was already converted, tho, the fittings would have adapters on them - or they'd have been changed entirely, correct? Seems like they've got a different set of fittings for every refrigerant out there - R-12, R-134a/HCF-134a, R-22, ... I suppose there's a good reason for that, but it's nothing that effective labelling couldn't handle, you know. How Murphy-proof does this need to be? What's wrong with a regular Schrader valve, or a short -AN with a manual valve behind it?

I'll grant that I don't know as much as I should about AC systems - but I'll be learning as I start working on these restomods I've got planned...

cherokee4fun said:

OK,

So I ran outside, and check the sticker again. It says "Freeze R12" on the crossmember for the radiator. I looked at the compressor it self, and it has a R12 sticker on it too. There are some strange ( to me anyway) fittings on top of the compressor. On my old 240z, there was only two fittings, in which to deal with. This one appears to have four, two on each line. Is there a visual way to see if this has been changed? I guess I need to look through my FSM to get another view of this.

I was thinking of bypassing the Condenssor Switch and see if it blows cool air. Any issues with doing that? Are those switches pretty reliable? It worked great last year and I think the PO did very little to it, so I don't he recharged before I got it. I guess the other thought is to take it to a AC place and have them check it. Any idea what that might run?

Thanks again for all the input.

Bob:rof:

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Sounds like it has R-12 and R-134a fittings (service conections) on the compressor. I have seen some new Sandon compressors like that. So it is probably not the original compressor.

What little I have heard about Freeze 12 was good.
It is touted as a direct replacement for R-12.
Here is one link on it (there are others, just google it):

http://freeze-12.com/

Sounds like you can buy a few cans and drop it in, but I would buy yourself a set of gauges and do it right first! Check the pressures and verify that it is low. You need gauges to fill it properly, to not overfill it!

I do not recomend bypassing the switches. They are pretty reliable. You can buy yourself a nice set of gauges for the price of a trip to the A/C service people.

I bought a new R-134a gauge set for $35 on sale at harbour tools not too long ago.

5-90 said:

Ah - everytime I'd seen a reference to AC systems (like in the FSM,) they called it "compressor oil" - so I'd thought it was different from the oil mixed in the refrigerant. My apologies for any confusion - at least I've been corrected now...

If it was already converted, tho, the fittings would have adapters on them - or they'd have been changed entirely, correct? Seems like they've got a different set of fittings for every refrigerant out there - R-12, R-134a/HCF-134a, R-22, ... I suppose there's a good reason for that, but it's nothing that effective labelling couldn't handle, you know. How Murphy-proof does this need to be? What's wrong with a regular Schrader valve, or a short -AN with a manual valve behind it?

I'll grant that I don't know as much as I should about AC systems - but I'll be learning as I start working on these restomods I've got planned...

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Yes FSM's like to make every fluid sound different and special. Helps the Snake Oil sales guys at the stealership counter sell more SO to the customers. (I was a snake oil sales engineer and formulator 30 years ago).

I have been doing my own refrigeration work for 30 years and some occasional industrial work years ago, and I was an R-12, R-22 user hold out until recently. I researched the hell out of the 134-a subject 2 years ago and I have a friend at a 40+ year old A/C wholesaler here that does retrofits and is the main A/C parts wholesaler for the Houston/Harris county area. I can get a $100 A/C special hose made up there for like $20 in ten minutes. I am also a chemical engineer now, so it is sort of my area of training, although I am more into the wastewater and environmental end of the business.

Sounds like cherokee4fun has a newer compressor for the older cars that has dual refrigerant capability fittings for R-12 and for R-134a. I have seen some online when I was buying my new one last year.

The fittings are just like fastners (like torx head bolts) and new tools for them. It's called planned obsolesence, got to keep the wheels and machinery of consumerism running or the economy turns to shit and everbody goes broke. You know, got to replace 8 track tapes with casssets, then CDs and now I-pods and satelite radios, R-12 with R-134a....

Reason, there is no reason, it's just company policy,LOL.:looney:
Gotta love em!!!!1

So, have you used Freeze-12? What was your impression?

I'm asking because I'm leaning that way on the restomods, but I've not yet gotten any reports from the field from actual users - I just see product lit when I look around. And I'd learned 'way back when not to trust anyone in marketing or sales, especially on technical issues.

As far as the whole "planned obsolesence" (sp?) thing goes - I think it flies in the face of all the "reduce/reuse/recycle" conservation efforts going on - and I don't like having to buy something in a few years because what I got the first time wasn't made any damn good. I couldjust be cranky about that, tho (and by the by - an 8-track is and remains the best way to listen to blues. John Lee Hooker just doesn't sound as good on CD...)

"Planned Obsolescence," says you. "Piss-poor engineering," says I. Designing something to fail is just plain stupid.

5-90 said:

So, have you used Freeze-12? What was your impression?

I'm asking because I'm leaning that way on the restomods, but I've not yet gotten any reports from the field from actual users - I just see product lit when I look around. And I'd learned 'way back when not to trust anyone in marketing or sales, especially on technical issues.

As far as the whole "planned obsolesence" (sp?) thing goes - I think it flies in the face of all the "reduce/reuse/recycle" conservation efforts going on - and I don't like having to buy something in a few years because what I got the first time wasn't made any damn good. I couldjust be cranky about that, tho (and by the by - an 8-track is and remains the best way to listen to blues. John Lee Hooker just doesn't sound as good on CD...)

"Planned Obsolescence," says you. "Piss-poor engineering," says I. Designing something to fail is just plain stupid.

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I have no presonal experience with Freeze 12 (yet..but I may try it myself soon), I have read a few guys saying they love it in various forums, and no one saying they hated it (yet).

I read a sort of partial living autobiography and expose on "Planned Obsolescence at GM" (PO) in a book written for John DeLorian by Patrick Wright when I was very young, 1979, called "On a Clear Day You Can See General Motors". It was a fascinating insight into the history of PO going all the way back to the 1920's, the Great Depression, WWII and the economic lessons learned from then. If you can ever get your hands on a copy of it I highly recommend reading it. It explains one of the core reasons we have so much trouble moving to an ecologically friendly and sustainable economy ("reduce/reuse/recycle" conservation efforts"). In many ways reading that single book had a huge effect on my environmental (chemcial) engineering career choices for the next 30 years.

From answers dot com: "Patrick Wright, author and former Business Week reporter, approached De Lorean with the idea of writing a book based on his experiences at General Motors. De Lorean agreed to dictate his recollections for Wright who would author the book. The final product, published in 1979, On a Clear Day You Can See General Motors"

It was written and published 6 years after DeLorian left GM as VP (he was on his way to becoming the CEO when he got disenchanted and quit GM) and written before he designed and built the now famous DeLorian car.

It was all about the moral conflict he felt as an engineer all the while that he worked in the Auto industry at GM with a design team tasked with the design job of designing for "Planned Obsolescence" (PO). As an engineer he wanted to design the best most durable vehicle, but marketing, economics and "PO" got in his way. He was a briliant, terribly frustrated, highly successful engineer (until the fall of the DeLorean Co.).

All of his life long frustrations eventually went into the Delorean car design! The body was made of stainless steel!

Great Scott!

On the "piss poor engineering" actually it does take some engineering talent to design a system that self destructs shortly after the car note is paid in full and the warranty has expired!

I never would have guessed you to be an 8-track fan, wow, LOL! I am stuck on cassette players myself, I never had an 8-track.

Gawd - I still have an old 1/4" reel-to-reel in cold storage! My first portable CD player wasn't very efficient - it took ten AA batteries! - but I found a cassette adapter to hook it into the cassette player in my car so I could listen to a good rendition of "The Wall" or "Dark Side of the Moon" (had the gold copy) while I was driving - but I still had an 8-track player mounted in the glove box so I could listen to Muddy Waters, Bo Diddley, or John Lee Hooker properly. Something about other formats just didn't seem to work for blues, for me.

I just may have to look for that book - should be an interesting read.

I'll agree that it takes a certain amount of engineering talent to work up constructive parts failure on a timetable, but it's misdrected talent - and why I'd not want to work for a major automaker. I'd rather build something that lasts a good long while and just retire early, and indulge in my hobbies.

I did talk to a few shops today about recharging my system. None of them deal with "Freeze 12". The reason I was told, not enough business for them to stock that coolant. One very good shop here locally, was very familar with it, but could only offer changing it over to R134. It would require changing the black canister ( condensor?) and recharging and changing the fittings. Total price of $200

I did see some Freeze 12 recharge kits on ebay and other internet sites. Just not sure how difficult it would be. Is it worth throwing $60 at a system that should be changed over, or will a simple recharge work. I have not done AC since the days when my 240z had AC, which is when I lived in San Jose, CA. Since then, all the AC was removed in favor of horse power.

Not sure how much I will use the AC, but I hate having some thing on my XJ not working when it's all there!

Bob

Gawd, this thread is long, sorry I just skimmed it, so I may be covering ground already covered.

BUT;
R-12 is still available, BUT, you have to have a license to purchase it, even on e-Bay. You can actually get your license online for like $20, its no more complex than simple High School Science class.

Freeze-12, correct me if I'm wrong, but isn't that a mix of refrigerants. The problem with using mixtures of refrigerants is that the gases leak at different rates and if you have the slightest leak (which it sounds like you have) then the mixture will change. I think Freeze-12 uses some propane and R-12 to circulate the R-12 Oil with the other refrigerants. The refrigerants that carry the oil would be the first to leak out and thus the oil would NOT circulate as well, if at all, and you can do damage to the system. (Thats the biggest reason you have to change oils with R-134a, R-12 mineral oil will NOT mix with it, so it won't circulate through the system, you have to use PAG or POE oils that do mix with R-134a so that it circulates.)

The Mixtures of Refrigerants do actually have better performance, especially in conversions that were originally designed for R-12. BUT, they having caught on, because of the leak problem, that changes the mixture and can be far more likely to have you damage the system, if the system is dependent on some portions of the mixture doing something critical, like circulate oil.

The Switch on the Condenser, has nothing to do with shutting down the compressor if pressure is too low. That switch turns on the fans to Condense the high side refrigerant when pressure gets high enough. That switch is the "Hi-Pressure Fan Switch", there is also a "Hi-Pressure Cut-Off Switch" to protect the system if pressure gets too high. The Condenser is the radiator for the AC system at the front of the vehicle, in front of the engine radiator. The evaporator is under the dash.

The "Low Side Cut-Off Switch" has a dual function. It cuts off the compressor when pressure gets too low, on the low side of the AC, at the exit of the evaporator. This prevents the AC from getting too cold and freezing up the condensation on the evaporator. If you have a leak and there is NOT enough refrigerant in the system to safely operate, because the oil won't get circulated with so little refrigerant, then this same switch won't trip and won't let the compressor turn on. The "Low Pressure Cut-Off Switch" is usually on the Expansion Valve at the Firewall, if its an orifice system, then the switch is on the low pressure side, usually on the return line near the evaporator/firewall.

Finally, yes your symptoms seem like the most common AC problem, a slow leak that causes the AC to NOT function in spring. BUT, you don't know that for sure. The only way to really know whats going on in your AC system is too put a set of gauges on it and measure the high and low side pressures at the same time and look at their relationship. A FSM that gives a table of those pressures according to ambient temps really helps as well.

It sounds like you've confused your terms and tested the system by shorting the "Low Pressure Switch near the Evaporator" That would turn on the AC compressor if you were low on refrigerant. Shorting the Hi-Pressure Switch at the Condenser in front of the Radiator, would only turn on the fan, never the compressor.

cherokee4fun said:

It would require changing the black canister ( condensor?) and recharging and changing the fittings. Total price of $200

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That is probably the Filter Drier, which needs to be changed anytime you open the AC system up and expose it too air, or change refrigerants.

Most Pro Shops will never touch Mixtures of Refrigerants, for the reasons I mentioned. If the system has a slow leak, it could destroy the AC system, which either forces them into arguments, small claims court, or ruins there reputation by word of mouth. The mixtures are just too risky and todays auto repair business, the current environment, wise and honest shops have to refuse to give the customer what they want often, because they'll get screwed over when something goes wrong.

Rick,

I did not realize there were 2 switches that turn on the AC condenser cooling fan. I will check my FSM on the wiring diagram on that high pressure switch going to the cooling fan. There is also one in the radiator on the 87-90 models.
I am not sure I buy the variable refrigerant leak rate problem for the freeze 12. Let me think on that one a bit. Yes, Freeze 12 is a blend or mix as I recall. If the freeze 12 is using PAG oil then some residual mineral oil should not be a problem.

You have my curiousity up now on the Freeze 12 ingredients and how it actually deals with the mineral oil. I think I will dig into that further.

From the sound of it he should get a set of gauges and some "how to use" instructions and try toping off his system with freeze12 (if it is low) and see how bad the leak really is (if it is a leak, which it probably is).

If it has a serious leak he should consider changing hoses, filter/dryer /receiver and probably the compressor and get it over with switching to R-134a, or go back to R-12 if he still can?

Having had Freeze-12 in it already certainly raises additional questions!

Ecomike said:

I did not realize there were 2 switches that turn on the AC condenser cooling fan. I will check my FSM on the wiring diagram on that high pressure switch going to the cooling fan. There is also one in the radiator on the 87-90 models.

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Hmmm, I'm going off what is normal for most systems. Perhaps that year XJ is different, or others. I guess you could go off a temp switch at the radiator, but AC works off the Press/Temp relationship of a closed system, when pressure hits a certain PSI, it is hot enough to need the cooling fan, and thus the cooling fan turns on. I'm not saying I know its done that way for a fact, but its done that way in almost all systems.

Ecomike said:

I am not sure I buy the variable refrigerant leak rate problem for the freeze 12. Let me think on that one a bit. Yes, Freeze 12 is a blend or mix as I recall. If the freeze 12 is using PAG oil then some residual mineral oil should not be a problem.

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Well the problem is, the different gases have different sized molecues, different weights and different press/temps relationships. Its like boiling a mix of water and alcohol, alcohol evaporates at a lower temp, so it will boil out of the water and evaporate before the water starts to evaporate. So if you have a leak in the AC system, the gases at higher pressures or smaller molecues will escape before the others, changing the blend or mixture of gases, because some of the refigerants are leaking out much faster than the others.

Ecomike said:

You have my curiousity up now on the Freeze 12 ingredients and how it actually deals with the mineral oil. I think I will dig into that further.

From the sound of it he should get a set of gauges and some "how to use" instructions and try toping off his system with freeze12 (if it is low) and see how bad the leak really is (if it is a leak, which it probably is).

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Its been a couple of years since I did the R-134a conversion in my old Mini-Van, that is when I research some of those alternative Refigerants. I may be thinking of different refrigerant, but I thought Freeze 12 was R-12 replacement that used the same oils and gave very close to same performance as R-12, because it used a blend of refrigerants that included some propane (not enough to be dangerous) and some other refrigerants that were miscible with mineral oil. The big draw back I saw, any leak, the refigerants that would move the mineral oil would escape right away, leaving behind the refrigerants that wouldn't move the oil, so the system would operate without oil circulation, I don't have to tell you what would happen in that case.

I thought, but its been a while, that the hydrocarbon refigerants in Freeze 12 made it incompatible with PAG or POE oils, it would contaminant those oils and break them down.

1990 4.0 xj 4 years ago was coverted to 134. I put in a open system radiator and the only problem I have is finding a little connector that will hook up to the compressor to charge the AC I have to charge it about every 3 years but that is not due to the conversion to 134. I have not had a bit of trouble..

Rick Anderson said:

Well the problem is, the different gases have different sized molecues, different weights and different press/temps relationships. It's like boiling a mix of water and alcohol, alcohol evaporates at a lower temp, so it will boil out of the water and evaporate before the water starts to evaporate. So if you have a leak in the AC system, the gases at higher pressures or smaller molecues will escape before the others, changing the blend or mixture of gases, because some of the refigerants are leaking out much faster than the others.

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Gotta disagree with you on this one point.

When I took O Chem at Purdue (back in 1986 or so...) one of the things we had to learn when learning to fraction solutions was the "azeotrope" - an admixture of two liquids that will bind - and will boil out together.

Water boils at 100*C
Ethanol boils rather lower - ~75*C, IIRC.

Mix water and ethanol, and it will boil dry at 78-79*C. The proportion is limited (95% ethanol/5% water - ish,) but the idea is that something can boil dry but not be a "pure" compound.

Here's a fairly simple definition in Wikipedia - http://en.wikipedia.org/wiki/Azeotrope

And here's a limerick, if you want really simple - http://www.oedilf.com/db/Lim.php?Word=azeotrope