R12 to r134 ac conversion. COST??

[sebros]

I have a 1982 silverado swb and I wanted to know the cost of this procedure if I do it myself and the cost of an autoshop. If I do it myself what would I need?
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[alabbasi]

Make sure that your system is leak free and then stick with R12. It espeally makes sense if you're doing it yourself as the price of R12 is about $20-$25/can these days if you buy privately which is only a little more then R134. It works better, requires no flushing and will probably stay in there longer.

[bowtiemanchevyman]

Originally Posted by alabbasi

Make sure that your system is leak free and then stick with R12. It espeally makes sense if you're doing it yourself as the price of R12 is about $20-$25/can these days if you buy privately which is only a little more then R134. It works better, requires no flushing and will probably stay in there longer.

where can i get some r12 i need some for my truck????

[alabbasi]

Check out ebay, they're is always someone selling some.

[1774btcrew]

Be careful buying R12 off Ebay. From what I have heard it is actually illegal to purchase it if you are not certified to use it. Environmental stuff. Watch around your area. I periodically see it at yard sales and swapmeets.

[alabbasi]

You can either get the certification which costs about $40 and can be done online. Or you can buy it for 'resale' purposes and then have a certified person install it.

[king-918]

R134a is the way to go. Just evacuate the system, pull into a vacuum for a couple of hours, Retro fitting will cost about $30 and fill as needed to get correct presures
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[alabbasi]

If you're going to R134, you'll need to change the oil to either ester or PAG as the R12 oil is not compatible. If you don't do this, you'll compressor will fail quickly.

[king-918]

G

Originally Posted by alabbasi

If you're going to R134, you'll need to change the oil to either ester or PAG as the R12 oil is not compatible. If you don't do this, you'll compressor will fail quickly.

Suggested not fact. I would worry more about seals. But then again I don't worry much
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[Jeepwm69]

I retro'd my old 85 Jeep over. Just swapped the fittings/ charge ports to R134 and put a new dryer on there. Charged it up and it works fine.

Seems like for the GM systems you're supposed to change the orafice valve too..... Mine's leaking so I gotta figure out where the leak is before I can do anything with it.

They also make "Freeze 12" which is supposed to work in R12 systems with no modifications.

When I retro'd the Jeep R134 was $3/can. Now thanks to the EPA tree hugging burecrats it's $10/can

[alabbasi]

Originally Posted by king-918

G

Suggested not fact. I would worry more about seals. But then again I don't worry much
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I don't really want to get into a disagreement before I get to 10 post but this is quite important. Please see following article from Dupoint which states exactly that using mineral oil in R134 systems will result in premature compressor failure due to lack of lubrication.

http://www2.dupont.com/Refrigerants/...va134a_mac.pdf

If I remember correctly, DuPont owns the patent for R12 and R134 so the information above should be accurate.




I'd be less worried about the seals as the worse that can happen if a seal goes is a leak. If the compressor fails, it could send debris through your a/c system which could mean that you would have to replace everything.

In order to 'correctly' convert to R134, seals and hoses should be replaced with R134 compatible seals and barrier hoses. As you'll open the system, you should change the drier. I consider this as recommended but not critical. What is critical is that at the bare minimum,you should.

Change the fittings
Add a label
Use ester oil which carries R134

The first two being a legal requirement.

In any case, once you start getting into it, adding a can of R12 to top off your system starts to become more appealing.

Originally Posted by Jeepwm69

They also make "Freeze 12" which is supposed to work in R12 systems with no modifications.

When I retro'd the Jeep R134 was $3/can. Now thanks to the EPA tree hugging burecrats it's $10/can

Freeze12 is what they call a blend refrigerant. It's about 80% R134 (+/-) and 20% something else which helps carry the mineral oil. The problem with blends is that if there is a leak, the ratio of the blend changes as different gasses will leak at different rates. Because of this, it really cannot be topped up and must be evacuated completely and re-charged, which can get expensive and wasteful.

[Jeepwm69]

http://67-72chevytrucks.com/vboard/s...d.php?t=408664

http://67-72chevytrucks.com/vboard/s...134+conversion

[king-918]

Experience vs a long letter? I'll stick with my experience as master ASE tch
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[alabbasi]

Originally Posted by king-918

Experience vs a long letter? I'll stick with my experience as master ASE tch
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This is Certainly your choice :-)

For any who are not master technicians, it's smart to read up on this because you don't want to create an expenisve problem when you're trying to find a cheap solution to fixing your A/C.

The conclusion on page 7 of the document above give you a good guideline on how to convert from R12 to R134a and is definitely worth the read.

[king-918]

Originally Posted by alabbasi

This is Certainly your choice :-)

For any who are not master technicians, it's smart to read up on this because you don't want to create an expenisve problem when you're trying to find a cheap solution to fixing your A/C.

The conclusion on page 7 of the document above give you a good guideline on how to convert from R12 to R134a and is definitely worth the read.

You won't create a problem. But do know I am not saying your wrong just overkill.
I've done this for people who can't afford the full replacement and for myself because I'm cheap. And not a bad idea to read your right on that too!
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[alabbasi]

Originally Posted by king-918

I am not saying your wrong just overkill.

I think that we see eye to eye on everything but the oil. As most conversion kits come with oil, people who use the kit should be fairly safe.

I'm not trying to throw money at a problem, I got my 609 certification 12 years ago because someone tried charge me $400 to charge an R12 system which i wasn't having

Since then, prices have plummeted and you can now get a can for $20 because demand no longer exists. Many of the cars that needed it have either been converted or scrapped.

From my perspective, if you still have an R12 system that is just a little low on Freon, the cheapest thing to do is to drop a can of R12 in and go. $20 dollars for a can, no vac, no oil change, no new fittings or o-rings etc.

Now if it's a system that hasn't worked in 30 years..... you're probably going to replace every piece of rubber on the system, if not everything else.

In any case, I suspect that the OP has some direction as far as converting his a/c so i'll bow out of this conversion.

With best regards

Al

[tucsonjwt]

I have had 2 old squares with factory A/C and the stock A6 compressor. My current 83 looks like it still has the factory Frigidare compressor. Both were changed over to 134A and both had significantly less cooling ability after the conversion. Now that R12 can be had cheaply and is still plentiful, according to a local A/C shop, I would stick with the R12. I am not saying that 134A does not work, just saying that R12 was way better in my trucks. On 110 degree days in the desert the 134A is noticeably less cool than R12. On moderately hot days - say 90 degrees or less - the the difference is negligible. However, at 90 degrees in the desert it is time to roll down the windows and leave the A/C off - maybe turn on the heater.

[gchemist]

Compressor - if yours is good, change oil and use
Condensor - R134 $130 for an updated condensor
Accumulator -
Orifice tube -
A/C line flush (isopropyl alcohol works too) use compressed air to flush condensor and evaporator
Kit to adapt R12 hose connections to R134 - you can but a kit. I don't like to use them because they are another location for leaks. use a set of R12 guages and use a R134 can fitting to charge it
Vacuum pump - harbor freight has them cheap, all you need are adaptors. You can swap all the part and have a shop just vacuum and charge it.
orings - hose connections rings need to be changed. Easy to do.
Hoses - R134 hoses have a plastic barrier beween the inside and outside. R134 molecules are smaller. Using R12 hoses will cause R134 to leak through the hoses. I had new hoses made for $100 at my local A/C shop

My R134 conversion with the above stuff cools down to 60 degrees on 100+ temp days!!

[Keith Seymore]

I just want to say I appreciate all the comments.

I have zero experience with A/C, but have got three coming up that need re-doing ('97 Suburban, '87 Pickup and '63 Grand Prix) - so I need to read/learn as much as I can in a short period of time.

K

[Firebirdjones]

I converted all my AC cars to 134 many years back (79 pickup, 88 Iroc, 72 chevelle, most recently my 72 blazer) and I've done a few for customers when the need arrises.

The easier ones by far are the newer R12 vehicles such as my 79 pickup.

I prefer to remove all components and flush, remove the compressor and drain. The evap I leave in the car and flush as well as the condensor. I like to make sure all old oil is removed and make sure there isn't any trash floating around. I simply use non chlorinated brake clean that evaporates and leaves no residue and then compressed air.

After that's done I like to replace all the 0-rings (it's all apart anyway). I reassemble with a new dryer (and orifice tube if equipped). I also like to poor a little pag oil in the evap and the compressor before assembly. Install the proper quick disconnect fittings,,,then suck it down for about 45 minutes. If it holds a vacuum I'm ready to charge.

Toss in the recommended pag oil and then 134 using gauges to watch high side pressure.

I don't bother to change any lines, and still use the old A6 style compressors as long as everything looks to be in good shape and functioning. If it's questionable I'll replace it.

My 79 pickup has been done this way for the last 10-12 years without a hiccup and blows ice cold in the AZ heat. Never had an issue with any of them. Most of your complaints of 134 not working as well comes from trying to use it with the old style R12 condensors that aren't as efficient and can't cool the 134 freon well enough. It can be easily changed if desired for a little more money.

It's very straight forward and simple, just take your time. I do agree that 134 has since gotten more expensive and it's starting to make the change over questionable. R12 is relatively easy to obtain and not much more money.
A recent trip over to a friend that runs a local AC shop I found that he has R12 freon, tons of it!! It's not much more money to just have him throw it in an older car, and actually cheaper than doing a 134 conversion.

[piecesparts]

R-12 was a great freon. It could be used just about anywhere and it works great.

R-134 is a touchy based chemical. An ounce too much and it won't cool and an ounce too little and it won't cool. You have to hit it right on the money. The Freeze-12 and Red-12 freons are a propane based gas and they do work, but it is jsut something that oyu have to get used to.

I have an R-12 system that I ahve not re-charged, since the cost of reon went up, but I have seriously thought it over several times this year. I really hate running my A/C on my toy, it just takes to much to support it from the performance of the engine.

[Edahall]

Do it right and do it once, or pay later.

[JPalmer81]

Just get the system evacuated and put the new freon in, the whole r-12 to 134a is a racket, you can replace the seals...if they are bad, i think you are over thinking it. And i am sure DuPont will tell you that you need to have all this money spent on your system for it to work correctly. I have been in the HVAC business for my whole adult life, so I have a smidge of experience. If you want to spend a whole bunch of money by taking your whole system apart and putting it back together, fine, not gonna hurt, but not necessarily gonna help either.


The main thing you need to worry about is if your system is leaking, u can find that by putting a vacuum on it and see if it holds, if it holds you are fine, just fill it back up with whatever freon u want (r12 or 134a) and you are good to go. Don't be surprised if you have a leak, automotive systems are going to leak no matter what you do, it might take one year or 15, but they will always end up leaking.

P.S. R12 is a better refrigerant hands down, the only reason they switched to 134a is because it is only a CFC while r12 is a HCFC, which the stinkin low life EPA that has been ruining or lives for the last 5 decades or so made it a mandate for the car companies to switch to 134a and phase out r12....like i said, it is a racket.

[Keith Seymore]

Originally Posted by JPalmer81

P.S. R12 is a better refrigerant hands down, the only reason they switched to 134a is because it is only a CFC while r12 is a HCFC, which the stinkin low life EPA that has been ruining or lives for the last 5 decades or so made it a mandate for the car companies to switch to 134a and phase out r12....like i said, it is a racket.

x2.

Slight subject change: anybody have a recommendation for a good "charging station" that can be purchased and used by a hobbyist? Can they be purchased through Summit or Eastwood?

How do you pull a vacuum in the system initially?

K

[JPalmer81]

If you buy a set of 134 and r12 manifold gauges (one unit) just hook up the high side to the high side schrader which is usually marked with a red cap, if the caps are gone it is the smaller diameter line, then hook your low side to the low side schrader(larger diameter line), then run the yellow hose that comes with the manifold gauges to the vacuum micron gauge, its pretty straight forward. Crack open the 2 valves on your gauges and turn the vacuum on and it will slowly vacuum down. A good number to shoot for is about -30 or so PSI of vacuum, when it gets down to that turn the vacuum off and let it sit for about 20 minutes or so and if it holds ur good, if it doesn't u have a leak, which will need repaired. After all this you take the yellow hose off the vacuum and hook it up to the freon, crack the valve on the freon and loosen your connector a bit till the freon starts to leak out, then tighten it back up then crack your valves open on the manifold and turn your car on with the AC on till your low side gauge reads about 40 psi and your high side reads about 150 or so, doesn't have to be right on. Then shut the valves on the freon and your manifold gauges and unscrew the hoses from the schrader valve and your all set. Like I said, if your system is not leaking when you pull the vacuum on it then I wouldn't touch a thing, just put some r12 or 134a in there and enjoy the nice cold air. :-)