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kaiserbud

A/C R134a Conversion - Problems

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I updated my 72 MC from R12 to R134a. It blows hot - can't figure out why. It may be the flush liquid or a POA?? I put in new Seals, Compressor, Dryer and Exp valve. It does not blow cold - maybe low 70's. If memory serves me, my pressure at 1500rpm is 225/35. At idle it might be 250/50?

 

I meticulously flushed the system using Intertrans? flush. It looked like chicken broth with milk mixed in. Very Oily - I thought how could this work - but used it anyway. I dumped 1.5 Quarts in only to purge 25% of it. I understand the evaporator has many 'pathways' out - so no matter how much air pressure I blew in - not much came out. I then had a buddy purge it with R22. Again - another recharge. Still no cooler. BTW - I used a new oil too - It had a red label??? Foget the name - Pag?

 

I have read some of the articles to resolve this issue, but need more input. My buddy has a 72 Cutlasss - his works great. I understand it might have a5 degree higher temp - but that is fine.

 

The sight glass is foamy - but I heard you never get it clear with R134a. There are no leaks and the hoses appear so soaked with R12/Oils that they seal well.

 

Now I don't know how a POA works - but could it be bad? Do my pressures indicate a blockage? Most importantly - is that flush kit I used screwing things up - I assume the flush has mixed well with the freon - but I can't seem to purge it.

 

I am open to do whatever necessary - just don't want to pull and clean the evaporator or replace it or the condensor unless i have to.

 

One last thing - out of frustration, I took it to a local shop to have them check it out. Just diagnoze so I could preferably fix. They were kinda irritated but checked it anyway and said that no matter what I did - it would never cool. They said the evaporator was too small as well as the condesnor. The evaporator may indeed be too small, but the condensor is huge!.

 

I read some archive articles and am now aware of the POA tube in Fort Worth - this will be done - can you guys help me out? Thanks - I think it might be the flush kit or POA.

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I have not done this yet but I am almost positve that you can not use the stock POA valve with 134A

You need the new style one. I believe that this is where you problem lies.

I am sure that someone will chime in here that has experience in this.

Try the forum search function, this may have been addressed before.

 

But hey August in Houston even 70 degree air must feel good!

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Kaiserbud,

I have used HFC Environmentally safe auto refrigerant that can be used as a drop in replacement for R12 and R134,it is called Duracool, it takes half the amount than regular refrigerants and works just as good if not better than R12.This a substitude for both refrigerants, without doing any modification to the current system.

 

I have bought this from a supplier at the Pomona auto swap meet here in Southern Ca,probably one of

the largest in the nation,the guy is a reputable

vendor and knowledgeable with Auto A/C systems.

 

I had a small leak in my system and used one of his other products(Proseal)to seal a leak in the condenser. Both of his products have worked well for me and have saved alot of labor and money.

 

Other products include,stopleak,prodry,system tune-up,dye charge,oil charge,and oil analyzer.

Ask him for his special offer,and pick his brain he may be able to help you solve your current problem.

 

If interested

 

Dan Williams

2005 Palo Verde Ave., #188

Long Beach Ca 90815

(562)841-0932

danwilliams@JGALT.US

 

 

Rod

 

 

fgmcc

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How did the DURACOOL work for you?

 

Have you asked your vendor if it is legal? smile

 

Sounds not too good to me, if I read the EPA statements here:

EPA on Duracool

 

Think I will go with Freeze-12 for my AC rebuild... smile

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Hey Andreas, I may be wrong but I believe freeze 12 has a flamable chemical in it and therefore is not suitable for automotive use. As far as I know, there are no truly "legal" drop in replacements for r12 (I hope someone tells me I'm wrong here)I really don't have a clue about the POA valve, so I am no help on that question.

Really, I just wanted to put my 2 cents in and let everyone know to read the labels carefully on any refridgerant you buy. If is dosen't say for autonotive use, it has something flamable in it and can be very dangerous.

Jim

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Is your heater control valve working? If it doesn't stop the flow of coolant through the heater core, you will be heating and cooling the incoming air at the same time.

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I had mine changed from R12 to R134 over 2 years ago and didn't have to change any of the original parts. I know some people have stated that parts must be replaced but nothing was replaced on mine and after over 2 years it is still blowing very cold air. I suspect those who have had to replace parts had to do so because maybe those parts were bad. Mine is a 1970 Monte

Rob

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Before everyone get's all upset, you need to look at what all the "substitutes" really are made from. Freeze 12 is 80% R134A and 20% filler. Duracool is a "hydrocarbon" based coolant. 134, Duracool and Feeze 12 are all FLAMABLE! R12 is not flamable.

 

The concern about flamability has do with the gas escapiing in a collision. Sorry to ruin you day however IF you have US or Foriegn car manufactured after 1994, it has 134 and 134 IS FLAMABLE. Some are more flamable than others.

 

The first commercially available refrigerant in the 20's was Sulfur Dioxide (SO2). This is now considered a poison gas. Mix SO2 and H2O and you get sulfurous acid. Example, breath SO2 and the water in your lungs turns to acid. In today's world, not acceptable.

 

Duracool is hydrocarbon based. So is gasoline, oil, plastic and many other things used in the manufacture and operation of your car everyday. Propane makes and excellent refrigerant. It is flamable. I can't recall the make up of Duracool however it probably has a variant of propane in the formula. In Europe, they use hydrocarbon based refrigerants exclusively in vehicles. Hydrocarbon based refrigerants more environmentally friendly and a operate more efficiently that 134. I USE DURACOOL AS MY SUBSTITUE OF CHOICE.

 

Freeze 12 as noted above is just a mixture of 134 and filler to step outside the EPA guidlines. It works, just understand what you are using.

 

The problem in your system will the the POA valve or orifice tube. One, the other or both are probably "stopped up". Before we blame the POA valve I need to know the answer to one question. Did you install a new "orifice tube". An orifice tube is the system filter. Alway replace this everytime you open the system. If you did not replace the orifice tube that may be your first problem. You could also have a stopped up evaporator or condenser. Unusual but not unheard of.

 

A POA valve regulates the system pressure mechanically. Many of the substitute coolants like 134 and Freeze 12 operate at higher pressures. These pressures are higher that the POA valve is set to operate. You can "adjust" ad POA valve a little on the inside with a screw driver. This never did much good for me. A better way to regulate system pressure is to replace the POA valve with a "Old Air Products" tube/cycling switch. This will operate the system pressure more like a modern car. If a POA valve was so good, they would not have discontinued it's use in 1974.

 

A lot of people has had success just changing coolant and the system still works. Usually not as good as R12, but works none the less. Your problem will be mechanical in the system. Your choice of coolant is not the problem.

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How did the DURACOOL work for you?

 

Have you asked your vendor if it is legal? smile

 

Sounds not too good to me, if I read the EPA statements here:

EPA on Duracool

 

Think I will go with Freeze-12 for my AC rebuild... smile

Andreas, I knew going into the purchase that the E.P.A. had some kind of restriction with the use of it in the United States,but when has that stop any of us from using or purchasing anything that's

either street legal or against the law.

 

I guess I forgot to mention :rolleyes: that it might of had a restriction in the United States,anyhow the Duracool is working just fine in my 70 monte.

 

I also agree with other posters that the root of the problem does not lie in the type of refrigerant being used,although it offers a good substitution for the illutted R12.Which can still be bought outside the United States in places like Mexico.

 

All I know is that I saved a ton of money using the DURACOOL and related products. Passing the Info along. laugh

 

Rod

 

 

fgmcc

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Duracool and Feeze 12 are all FLAMABLE!

R134 and Freeze 12 are very close to be the same. They are flammable under certain conditons. Duracool and HC12 are HIGHLY flammable!

 

Just wanted to point out that the EPA fine for illegal conversion from R12 to Duracool or HC12 is up to $25,000. Of course, that's only if they ever catch you... laugh

 

The issue is not that DURACOOL can be a good refrigerant, but is it a substitute for R12. In Europe, the A/C systems are DESIGNED to work safely with Duracool.

Who thinks that the A/C system in our 34 year old Montes were made to work safely with Hydrocarbon refrigerant? Just a thought... smile

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Originally posted by Andreas:

[QB] [

Just wanted to point out that the EPA fine for illegal conversion from R12 to Duracool or HC12 is up to $25,000. Of course, that's only if they ever catch you... laugh

 

Andreas,

That might apply to commercial use or possibly in large scale use,one wonders if that type of enforcement might apply to some hobbyist like me?

 

Rod :rolleyes:

 

 

fgmcc

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Andreas,

That might apply to commercial use or possibly in large scale use,one wonders if that type of enforcement might apply to some hobbyist like me?

Most likely you are safe. That's why I said "that's only if they ever catch you..." smile

 

Should have said: "if they ever bother..." smile

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The discussion is interesting on alternative freons and additives, but its not the topic - can anyone advise on issues I might be experiencing to resolve my problem? I appreciate the FGMC team advice.

 

I will verify the heaterhose and any valves are in working order.

 

MJS - I read some of your other posts and see your expertise. I do not think I replaced (or have) an orifice tube. Isn't that on newer model condensors that have a different style tube arrangement - and ultimately coordinate with an accumulator? I may have this info all backasswards.....thanks

 

And on the Old Products POA - they were very helpful - I called them yesterday as recommended in one of your previous posts. If I have to remove the POA to adjust the screw (?) then I figure I should do the new POA and dryer.

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Andreas,

 

Your comment that "systems in Europe are designed to work safely with Duracool" has me puzzled? No matter how good your design, there is no A/C system that "crash proof"! With a condenser hanging out front of the radiator and hoses under the hood, it is impossible to design a system that will no be punctured/compromised in an accident. When the system is punctured, the gas is released. If there is an ignition source, you "can" have a fire.

 

The possibility of a fire is no different with 134 and Freeze 12. Yes, Duracool has a higher flash point and is "more" flamable, however 134 and its derivitives can also catch fire in an accident with the same or similiar source of ignition for the fire.

 

Duracool is legal in Canada and everywhere else in the world. Kinda makes you wonder why not HERE? Maybe there are some patents expiring or the lobbyists for Dupont (134 Patent holder) are better than the hydrocarbon refrigerant lobby in Congress. That's usually the way things work in Washington DC.

 

Global warming and the ozone issue were a big issue with the killing of R-12. Flamability was discussed but that was it. Apparently our Congress and lawmakers are again trying to be big brother and tell us what is best for us and that is 134. We can use gasoline, pump gasoline and spill all the gasoline we want at the service station. Gasoline is as or more flamable than Duracool. Somehow "I" think pumping gasoline is a MUCH greater safety issue than a hydrocarbon refrigerant. But what do I know?

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Your comment that "systems in Europe are designed to work safely with Duracool" has me puzzled?

Gasoline is as or more flamable than Duracool. Somehow "I" think pumping gasoline is a MUCH greater safety issue than a hydrocarbon refrigerant.

Mike,

 

Maybe we should start a new thread for this 'philosophical' refrigerant discussion... laugh

 

Sorry, you are right about the safety of the A/C system. I should have said: "The newer cars are designed to be as safe as possible with flammble refrigerant air conditioning"

As far as I know, the Car Manufacturers who use flammable refrigerants in A/C systems are actually designing cars with crash tests, taking into account the risks of flammable refrigerants . For example, one of the greater risk is the hood latch assembly puncturing the A/C condenser in a frontal collision. The newer cars are designed to minimize this risk.

If I look at my Monte's hood latch arrangement, brrrrr... smile

 

 

I knew that gasoline would come up... smile

 

Just quoting the EPA:

"There are good reasons why gasoline and other fluids may be used safely while the use of hydrocarbon refrigerants in A/C systems may not be safe. Gasoline and other flammable substances are used in systems designed specifically for flammable fluids. A gas tank is deliberately placed in the middle of the rear part of a vehicle to protect it against collisions. Air conditioner condensers, in contrast, are placed at the very front of the car to maintain good air flow. Unfortunately, this location means that condensers may be punctured during a front-end collision. Another difference is that unlike gasoline lines, air conditioners include lines that provide cooling directly to occupied areas -- in this case, passenger compartments. Flammability risk is extremely dependent on the specific system being considered; the simple presence of other flammable fluids in a car does not address the safety of using hydrocarbon refrigerants in an automobile air conditioner."

 

I agree that DURACOOL/HC is probably the best refrigerant on earth! Non-toxic, non-greenhouse, you need less, etc.

 

IMHO, the reason for it not being officially accepted in the US are probably the US product liability laws, which scare everyone away... smile And then there is the lobbying of the chemical industry as you pointed out... smile

 

I am still looking into a claim I read that auto insurance will be voided in a collision when using non-approved refrigerants...

 

All I want to point out is that everyone retrofitting from R12 should be aware that R134, Freeze 12, DURACOOL, HC 12 and so on are all flammable compared to R12, that's all. Can we all agree on that? laugh

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I believe our cars only have a POA valve. THe CCOT (clutch cycling orifice tube) was used on later models and replaced the POA. You can purchase a POA valve eliminator kit for about $99.00. My only concern is how well wil the old A-6 compressor standup to being cycled on and off.

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one bad, i went with the old air products elim. tube because the experts told me the poa valve were a bad design. the place that rebuilt my old compressor told me they were basicly bullet proof. gene

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Gene, how does the orifice tube compare with the POA setup. I'm assuming your old system was in working order, if not how well does the system work with orifice tube? Thanks, Bob

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bob, the eliminator tube isnt really a orfice its a straight tube with a pressure switch screwed into the side, once the pressure gets so high it disengages the compressor. it pressure switch has a pigtail connector that splices into the compressor wire. i think it works like the newer gm systems.gene

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Kaiserbud. If I read your post right I may have something here for you. You mentioned about PAG oil. If in fact you used PAG oil that is your problem. Pag was only intended for virgin R134A systems. It can not be mixed with the the oil that is in there now. I know you said you flushed it. However getting all that old oil will be nearly impossible. Hence the milk color. You also did not mention anything about vacumm or changing the drier????? Your readings look good at high RPM but a little high at idle. Which leads me to think you have not boiled off the moisture (Puuling a deep vacumm). If I were you I would start by separting each componet and and get a gallon of flush. Do the entire system One piece at a time except the drier in which you will replace. If the POA is still good it will work with the R134a. Total BS from shop about size of Evaporator and Condensor. With that in mind I would advise that you stay far away from that shop in the future.

 

You may also want to replace all the seals with the green colored style seals when using R134a to keep leakage at a minimal. There will be some leakage thru the hoses but not enough to be a concern.

 

I did my MC conversion w/no problems only thing I did was change the drier and pull a deep vacumm for 2 hours. That is critical.

 

Go back witht a ester base oil and not pag.

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Excellent - thank you - I will try this - I did pull a good vaccum and did replace the drier - but will do so again as directed. Give me a week or so to follow up - Fall baseball isstarting and work - you know the drill....

 

Anyway - thanks - I will let you know smile

 

BTW - I think also that the shop is not aware of how well the 134a conversion works.

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