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EL Cheapo R134A "conversions" post up!

:bow: Rufus :bow:


Impressive info..... And I don't think it's because you stayed at a Holiday Inn last night. :waytogo:

My mom's got a 20 year old Honda CRX (she's a pretty cool "old" lady) and the original R12 system is not blowing cold anymore. My temptation was to just pay the premium price for real R12 and get it recharged. I have no idea how many pounds it would take, but the system worked great for many years, so I would expect it to last many more once it was charged again.

I was fascinated reading about the DuPont family (DuPont held the original patent on R12) and the rumors that the whole R12 "Ozone Layer" claim was a complete fabrication used to remove it from the market before the patent expired, and DuPont could no longer charge royalties. The replacement (R134) was developed....also by DuPont as a way to keep those royalty dollars flowing.

Don't know how true the story is, but it really strikes a chord with my "the whole world is corrupt" feelings of late. :wink1:


:usaflag:

Happy 4th of July everyone....
 
Great information, but I don't think it fits with the OP's intent of "cheap" conversion.

When I finally convert the Blazer, it will get parallel flow condensor, new dryer, orifice tube, and new hoses. The compressor works quietly and well, but it is low on refrigerant, so the PO spliced the pressure switch to constant on, so you have to turn the A/C off to keep from freezing the system.
 
Rufus,

That was excellent information and it was presented in a very understandable method.

I think it's the best description of the process I've seen anywhere. As someone who is faced with R-12 or R-134A conversion soon, I very much appreciate the post!
 
Yes, that was a great post Rufus. Thanks for all the info. That is more time and $$$ than I want to invest though. I hate to ask what the "wrong way" to do it is, but if I just replace the desiccant (stock replacement is fine, the oil is the problem right?), have an AC shop pull a vacuum , and refill with a R132 "conversion kit and leak detection dye will it work OK for a while? That is all I'm looking for "some" AC for a couple years and then I'll do it as you described.
 
Replacing the dessicant is the same thing i said to replace in my post. It is the drier.
The drier is the can by the firewall. You should replace it with a new one if you do the conversion.
You should disconnect and remove the compressor to drain all the oil out of it. Blowing compressed air thru the hoses should remove the rest of the oil in the system.
When you add the 134a/oil be sure to use POE (Ester) oil not PAG oil.
The POE oil is compatable with any mineral oil that may be left in your system. Most retro fit kits use the POE oil.
Then hook everything back up vaccum, recharge.
Spend a little time now and do it right. Why risk blowing an expensive compressor with a quick fix?
 
Thunder is correct and that is the minimum that is required to convert.
The receiver/dryer must be replaced. It holds the desiccant and can not be cleaned out. It will come with o-rings for when you replace it.
You will also need to get as much of the oil out as possible. Thunder is correct recommending that you remove the compressor to get out as much mineral oil as possible. I would also recommend removing the o-tube in order to blow air through the system to get as much oil out as possible. That will require the purchase of 1 new o-ring but will allow you to blow the oil out of the evaporator.

Make sure that you add the new ester oil to the system in the recommended quantity. Try to distribute it throughout the system as I recommended in the previous post. You definitely need the ester oil if you are not flushing the system.

Agreed the method that I mentioned was not the cheapest but really only costs a bit more. O-tubes are a couple bucks. A full o-ring kit is about 15 dollars. An extra can of oil, and a gallon of lacquer thinner. The rest is labor.

In any case either method will get some cold air out of the system. Just want everyone to know all the options. Hope that helps.

Cheers,

Rufus
 
Thanks for all the info guys, this is on my list of things to do. Hopefully I get to it before winter. :D
 
I keep wondering if the whole "R12 is evil" thing has finally blown-over... There was a big push to convert everyone away from R12 (coincidentally as the Dupont exclusive patents were about to expire)... but now that anyone can create R12 formulations without paying patent royalties, I wonder if the costs are coming back down??? It sure seems like suppliers have no problem offering it for sale on the internets. :dunno:

Some quick internet searches show that R12 is very easy to find, and not particularly expensive either....at least not compared to the conversion costs to a 134a system.

Example:

http://refrigerantsales.net/shop/index.php?main_page=index&cPath=1_5


Maybe Rufusbooth can comment on this??



:usaflag:
 
One thing to keep in mind is that R-12 is still legal to sell if you have the proper certification and since "new" R-12 can not be manufactured the price is very market driven.

Basically R-12 can be indefinitely recycled and as long as people keep collecting it from older systems and having it recycled R-12 will remain available.

In this case prices are now starting to be driven by the market back down because there are less cars on the road using R12. I think we are seeing the price stabilize now that the FUD as died down and people realize it is still available. But, it is still 600% higher than r134a even at the prices mentioned in the link above.

Although, even R134a is now in the cross hairs. The EU has basically banned new vehicles (I think 2013) from using R134a and are now looking for a new replacement. The US will follow suit because they will not want to make 2 different AC systems for new cars.

Fun times ahead for all of us....


Rufus
 
Maybe I'm missing something obvious....but how many ounces would it take (as a rough average) to fully charge an empty system with R12?

I've been considering getting the AC in my Porsche 911 up and running with new barrier hoses to prevent weeping refrigerant and figured maybe a few pounds is all it would take to do a full charge.... If I could buy 4 12oz cans of R12 @ $29 ea, that doesn't seem like an excessive amount of money for a full charge....but maybe it would take a whole lot more than 48oz to get a brand new system up and running.

Still, I seem to read everywhere that a properly running R12 system will still blow colder than almost any of the newer refrigerants...so I'm tempted to re-build with R12 and not bother with a full R134a conversion (especially if it won't even work as effectively!)

:thinking:



:usaflag:
 
Your AC system should have a tag saying how much it takes to fill. My Blazer's tag read 3.25 lbs of R12.

Rene
 
It depends on the year of the car for the capacity. I am not completly familier with a 911 but given it is going to have a BUNCH of pipe running from front to rear (rear engine) then it will most likely be a larger capacity system. Probably more than 3 lbs worth. But, as tRustyK5 said, there should be a tag in the engine compartment that indicates the full R-12 charge.

With regards to the cooling ability of R12 vs R134a there are definitely differences. All things being equal you will need more condenser capacity to have r134a to cool as well as R12. That being said, a system that has the proper amount of condenser capacity for R134a will actually cool better than an R12 system.

There are 3 ways to increase your condenser capacity (or a combination of the 3).

1. increase air flow over condensor by larger fans or air redirection/sealing.
2. Increase the physical size of the condenser.
3. Move to a more efficient condenser design (serpentine vs paralell flow).

Now, having said all of the above as I understand it the condensers on a 911 are really small and have poor air air flow. I am not realy familier with the 911 but you may be limited with all 3 of the above options to increase your condensor capacity. I found several references to people trying to increase the condenser capacity even when staying on R12.

In your case it may be a smart move to stay with R12 but keep in mind you will not be able to buy the R12 yourself. You will have to purchase it from the AC shop that will service the AC. you need a federal certification before anyone will sell you R12 whereas r134a can be purchased at the local walmart by anybody. That will most likely make the R12 a bit more expensive than your online sources. you will need to get some local quotes to see how much an AC shop will charge.


Other cars like our K5s have options to increase condenser capacity in all three areas and in my mind makes it a no brainier to convert to R134a if you plan to keep the car for any length of time.

In the end...It is really an application call of you want to swap or not.

Let me know if you have any other questions and I will be happy to answer them if I can.

Rufus
 
I'm in the middle of doing this the right way now. I had to replace the condenser, I bought a new dryer and removed the compressor. So the only part I have installed is the evaporator core. I've removed the o-tube and blew out the oil in the evaporator.

My question is this. Should I now use PAG oil or Ester oil. Is PAG a better oil or should I just go with Ester since there may be a slight residue somewhere in the evaporator or compressor still?

If they are equal... I'll just go with Ester. Otherwise I'll get some PAG oil and run it through the compressor manually and do some extra work to make sure every drop of mineral oil is out of the evaporator.

Other than that, I have to find out how much oil is required for a 1985 K5. Anyone know?
 
I do all of my A/C work with synthetic oil from Australia. It's compatible with both Ester and PAG, so it works on everything. But the simple answer is to run only one type of oil and the oil should match the refrigerant.

Also, I didn't see it called out here, but you should replace the orifice tube when converting, since the refrigerants have different requirements.
 
I tried one of those $30 el-cheapo conversion kits on my '89 Ford Taurus wagon (it was a gift) that previously breezed jet exhaust from the vents.

Now it's cold as ice in there. I live in Colorado and on a 90* day it's cooooooold in that thing.

Quite a bit better than the K-note that I was quoted for converting it "properly."
 
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