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DBMaster
04-09-2011, 09:19 AM
You guys are gonna LOVE this. NOT!

"Owners of 1994 and newer cars, this is the time to fix your air conditioner. Not just because warm summer days are coming (hurray!) and RockAuto has AC compressors, condensers, evaporators, and other AC parts that we are eager to sell. Fix your AC because you will soon officially be joining the owners of 1993 and older cars in having environmentally unfriendly and expensive refrigerant under your hoods.
In 1994, R-12 (branded as Freon) refrigerant was replaced with R-134a in new vehicle AC systems. R-12 had contributed to holes in the earth’s ozone layer. Production of new R-12 was banned in the United States and most other countries. The price of recycled R-12 skyrocketed. R-12 smuggling became as lucrative as drug smuggling. The last time I had an AC system charged, the R-12 cost $60 a pound.
Now R-134a is on the chopping block because it has a “global warming potential” (GWP) of 1400. Carbon dioxide is the baseline with a GWP of 1. This means R-134a is a greenhouse gas that contributes to global warming 1400 times as much as an equal amount of CO2.
Regulations now specify that refrigerants have a GWP of less than 150. New vehicles in Europe are required to have low GWP refrigerant starting this year. In the US, low GWP refrigerant will be phased in from 2013 to 2016 depending on the vehicle manufacturer.
The preferred new refrigerant is something called R-1234yf. It has a GWP of only 4. It requires special lubricating oils and handling equipment. It is also slightly flammable. AC fittings will be changed to help prevent the mixing of R-1234yf with R-134a.
This time around the production of the old refrigerant, R-134a, will not be banned. But R-134a will be federally taxed so its price is forced up from about $10 a pound to about $40 a pound, the expected price of R-1234yf. The tax is intended to further discourage people from attempting to use R-134a in one of the upcoming new cars designed to use R-1234yf.
This means refrigerant for the typical two pound R-134a AC charge will cost $80 instead of $20. That lost $60 might buy an AC O-ring set, an AC receiver drier or help pay for labor or other needed air conditioning parts. If your AC system needs work or frequent recharging, you will likely save some money by fixing it sooner rather than later."

w261w261
04-09-2011, 10:04 AM
I recharged my car with R-12 when I bought it in 2001, put about a pound in it in 2005 and again in 2009. Original compressor. Isn't R-12 colder than the others?

ghettogeddy
04-09-2011, 11:02 AM
I recharged my car with R-12 when I bought it in 2001, put about a pound in it in 2005 and again in 2009. Original compressor. Isn't R-12 colder than the others?

yes

DBMaster
04-09-2011, 11:32 AM
I copied the text from Rock Auto's latest newsletter, by the way. I put in a new compressor last year and have Freeze 12 in the system. It's a mixed refrigerant that can operate with the same mineral oil and similar pressures to R12. Is it as cold? No. I have been measuring vent register temps and it's about three degrees warmer. I would call it "acceptable," though, I might yet use up my last three cans of R12 to redo it in the future. What was interesting to me is that you'll still be able to get R134a, but the price will be artificially inflated to match the price of the newer stuff. I guess you won't be topping off systems with $6 refrigerant anymore. I sure wish I didn't live somewhere where it's like a sauna for five months out of the year!

Dr_Snooz
04-09-2011, 12:04 PM
That tears it. I'm going with propane. They never regulate hydrocarbons, so that's what I'm going with.

DBMaster
04-09-2011, 03:28 PM
^^That is uncanny! Those were my thoughts exactly, Doc!

Pnem3
04-09-2011, 07:05 PM
That tears it. I'm going with propane. They never regulate hydrocarbons, so that's what I'm going with.


^^That is uncanny! Those were my thoughts exactly, Doc!

Come on over. It's nice and cold here. I've been running propane and iso-butane in my 3G for at least 4 years now I think with no problems whatsoever.:D

My vents would literally freeze if I let them.

Like I always say, it is not for everyone but it works for me.

Dr_Snooz
04-09-2011, 09:10 PM
You need to do a how-to. My brother is an engineer and gave me an earful about how propane is only half as efficient as R12. I kept telling him I'd heard it was equally as good, but he dropped the whole "I've done the math" deal on me. How do you argue with math?

DBMaster
04-10-2011, 09:02 AM
Here you go. Not as cheap as DIY, but it's pre-blended...

http://www.epa.gov/ozone/snap/refrigerants/hc-12a.html

Oldblueaccord
04-10-2011, 09:32 AM
That tears it. I'm going with propane. They never regulate hydrocarbons, so that's what I'm going with.

Reading the EPA its illegal. That being said so are a lot of things.

I just removed my non-working seat belts and installed 4 point harnesses that are DOT approved. Technically illegal but to me a great safety improvement.


wp

DBMaster
04-10-2011, 12:52 PM
If you read further you will notice that you can convert an R134a system legally to an HC refrigerant. Most of the commercially available ones look like various blends containing propane and butane. Somebody made the comment on an A/C web site that you could basically put R134a fittings on your car and say, "Yeah, it's been converted to R134a." Then, it's legal. Funny how government rules work sometimes, isn't it?

DBMaster
04-10-2011, 12:53 PM
That tears it. I'm going with propane. They never regulate hydrocarbons, so that's what I'm going with.


Doc, I did some reading. It seems that the vapor pressure, or some other characteristic of propane causes it to freeze the evaporator unless you mix in something else, like butane.

Pnem3
04-10-2011, 07:39 PM
You need to do a how-to. My brother is an engineer and gave me an earful about how propane is only half as efficient as R12. I kept telling him I'd heard it was equally as good, but he dropped the whole "I've done the math" deal on me. How do you argue with math?

His math is wrong. A propane / iso-butane blend is more efficient and you need less of it to do the job. You run lower pressures and actually save gasoline too:cheers:


Doc, I did some reading. It seems that the vapor pressure, or some other characteristic of propane causes it to freeze the evaporator unless you mix in something else, like butane.

The iso-butane (the iso part is important) keeps the high side pressures lower than if using straight propane.

There are many how-to's on the web but I may do one for our cars.

I say again, this isn't for everyone and I spent hours and hours researching before I made my decision. I couldn't be happier.

Dr_Snooz
04-10-2011, 08:02 PM
Reading the EPA its illegal. That being said so are a lot of things.

I just removed my non-working seat belts and installed 4 point harnesses that are DOT approved. Technically illegal but to me a great safety improvement.


wp

I hear you Walt. I'm all for staying within the limits of the law. I've counseled quite a few people on this board to convert to 134. Yet when the law mandates that you go to all the trouble and expense of converting to 134 because R12 is so bad, then you have a right to a reasonable expectation that the ground isn't going to shift under your feet again later on. Some of the early adopters spent thousands of dollars switching their cars over to 134. The rest of us did without AC altogether for ten years or so until we figured out how to do it cheaply. They should not come back a few years later and say "Just kidding, 134 is the really bad stuff now. Just redo everything you did a few years ago." That's the kind of thing that makes people ignore the law. One new Super Duty pickup is going to spit out more greenhouse emissions than all the cans of 134 I will ever buy. So why would I bother? In my case, I see that Exxon and BP can smear hydrocarbons all over everything without suffering any real consequences, so I know that if I convert to hydrocarbons, they won't come back later and pull them off the market.

Dr_Snooz
04-10-2011, 08:39 PM
Apparently, it's illegal to convert from R12 to propane, but not from R134 to propane. LOL You don't even need a vacuum pump to create a vacuum before filling. You don't need to convert any oils. Just fill it. If you have an R12 system, you don't even need gauges to fill it, just use a tire gauge. Propane is more efficient than regular refrigerants. Head pressure is lower too.

Unbelievable.

mcs32jr1968
04-10-2011, 09:38 PM
Come on over. It's nice and cold here. I've been running propane and iso-butane in my 3G for at least 4 years now I think with no problems whatsoever.:D

My vents would literally freeze if I let them.

Like I always say, it is not for everyone but it works for me.

that's cool...(excuse the pun). any DIY or instructions for clowns like me who would like to attempt a propane/iso butane recharge instead of R12???

ps..is it dangerous (flammable??explosive??)to have propane/iso butane instead of the old R12 refrigerant??

peace,

mcs

Xaisk
04-11-2011, 10:34 AM
I always heard that propane was safe so long as you dont get a leak or get in a wreck. I knew a guy who knew somebody who did a propane conversion and got into a wreck. He would have survived but the AC lines were severed, allowing the propane to escape and come in contact with the fire. I dont think it caused an explosion but im sure the flames blazed...

Pnem3
04-11-2011, 02:39 PM
Everybody knows a guy who knows a guy who had something happen to him. Funny thing is no one ever hears from that guy directly. I spent hours and hours doing research on the net and I suggest that anyone who even considers converting to hydrocarbon refrigerants does the same. For me, in the end, I found that the dangers were greatly exaggerated. I also found that there is no easier or efficient or cheaper way to convert our vehicles.

Dr_Snooz
04-12-2011, 08:20 AM
He would have survived


Funny thing is no one ever hears from that guy directly.

Um, maybe because he's dead? :rofl:

Seriously though, propane IS flammable. But so is 134. Propane auto-ignites at a HIGHER temperature than does R134. Remember too that in most modern fuel-injected cars, you are surrounded by a lot more gasoline under high pressure than you would have propane in the average AC system. Given the right circumstances, you could get the propane in an AC system to ignite, but I don't think there would be enough there to cause much of an explosion, especially if there were a rupture that allowed the propane to disperse into the air before igniting.

The only thing that gives me pause about propane is that you are basically on your own in maintaining it. Once you use propane, from what I've read, you can't take the car into a shop and have a service done. Nor can you go back to a conventional refrigerant and have a shop work on it. The propane contaminates the system and no shop will be able to use its machines to do any kind of service or recovery. It would damage their machines and they would have to replace them. If you wanted a shop to service the car again, you'd have to replace all the components in the system first. I do all my own work, so that's not a problem for me, but it's something for people to consider before making the switch.

DBMaster
04-12-2011, 09:03 AM
If you are a fan of "Mythbusters" you can make some deductions and realize that the chances of having an explosion due to a little propane in your A/C system are about as close to zero as you can get. When I was a kid people used to say that if you played around with WD-40 and used the can as a torch the fire would "back up into the can" and blow it up in your hand. Pardon my French, but bull-crap. Even if you had a total car fire one of the rubber hoses would weaken first and then let the refrigerant out in a stream. Again, no explosion. If you don't want to try propane, that's fine. I just don't understand why everyone has to rationalize their decisions with fear-based propaganda. I won't do it because I have actually had shops replace my A/C system and I want to be able to get it done in the future if I still have the car.

I think I truly mean it this time when I say I give up. There are too many people who are just too convinced that their misinformation is gospel truth.

Whenever I see an A/C post I cringe because it starts one of these discussions all over again and like Al Pacino, "they pull me back in." :)

DBMaster
04-21-2011, 05:01 AM
Practicality figures into the equation, too. I have enough R12 on my shelf to fill the system - once. That would not leave me enough to add the half-can per year that the car has lost since it was new. This continued even after putting in a new compressor in 1999 along with new hoses, o-rings, drier, and schrader valves. I let Danny's Import Services put in Freeze 12 last August when I replaced the compressor again, which is what they retrofit to all R12 systems. I did it because at least for the near future I can get more and the shop can service it if I don't want to. Funny thing is that the system doesn't seem to have lost any of this stuff. I always thought R134a (Freeze 12 is mostly R134a) would leak MORE readily than R12. Who knows. Maybe my old compressor had a leaky shaft seal. The new one is like the one from 1999, a brand-new Denso unit.

Oldblueaccord
04-21-2011, 07:26 AM
If you have a Biglots near you they have a sale for 8$ a can 134a this week.


wp

Dr_Snooz
04-23-2011, 03:07 PM
I just picked up a couple cans for my mom's car. A can now runs $18.99. Plus, you need an adapter to connect your existing gauges to the new cans. PLUS, you have to pay a $10 core charge for each can. Out the door cost for two cans: $66. Yikes.

Propane keeps looking better. Incidentally, it is a recognized refrigerant referred to by the code R290.

Pnem3
04-23-2011, 04:11 PM
A core charge? How can that be? Are they going to refill the cans? It's probably to keep people from hoarding them because the core charge can't be redeemed far into the future. What a ripoff.

YK86
04-24-2011, 01:58 AM
Since we are on this topic, I converted my 90 Accord to R134a using those $40 Walmart conversion kits that everyone seems to bash. Since it was for my own car and had nothing to lose, I changed all the o-rings and drier for about $30, but filled it with the r134a without get the system vacuumed "properly". It's been over 5 years now and I have not had to fill it once and it still blows nice and cold even on the odd days it hits 100F here in Vancouver. It may not be as cold as r12 but I'm actually really happy with it, especially since it was less then $80 after tax to do it.

Now just recently, it's been warming up here and I ended up doing the same thing on the SEi for the hell of it (it's already been retrofitted but the I think the o-rings were bad and had no pressure).I didn't have time to go into the US to get more of the "usual" Interdynamics r134a so after reading up on a few AC related sites, I felt comfortable enough to grab a few cans of $10 12A (the HC based stuff that's compatible with r12 and r134a) from the local parts store plus the o-rings and drier ran about $50. I actually find the 12A blows cooler than the r134a in the 4th gen just like the tech guys on the AC said.

Anyone else find this as well?? I'm in Canada so I don't know what prices the Interdynamics r134a is recently in the US (it was $8.99 for r134a and $12.99 for Arctic Freeze last fall) but I think I'll be using 12a from now on.

dieselgus
04-24-2011, 07:30 AM
Since we are on this topic, I converted my 90 Accord to R134a using those $40 Walmart conversion kits that everyone seems to bash. Since it was for my own car and had nothing to lose, I changed all the o-rings and drier for about $30, but filled it with the r134a without get the system vacuumed "properly". It's been over 5 years now and I have not had to fill it once and it still blows nice and cold even on the odd days it hits 100F here in Vancouver. It may not be as cold as r12 but I'm actually really happy with it, especially since it was less then $80 after tax to do it.

Now just recently, it's been warming up here and I ended up doing the same thing on the SEi for the hell of it (it's already been retrofitted but the I think the o-rings were bad and had no pressure).I didn't have time to go into the US to get more of the "usual" Interdynamics r134a so after reading up on a few AC related sites, I felt comfortable enough to grab a few cans of $10 12A (the HC based stuff that's compatible with r12 and r134a) from the local parts store plus the o-rings and drier ran about $50. I actually find the 12A blows cooler than the r134a in the 4th gen just like the tech guys on the AC said.

Anyone else find this as well?? I'm in Canada so I don't know what prices the Interdynamics r134a is recently in the US (it was $8.99 for r134a and $12.99 for Arctic Freeze last fall) but I think I'll be using 12a from now on.

Hmm.....may have to give Lordco a call in the morning. My compressor went in spectacular fashion last summer and changing out the AC system is on the to do list this year. Figured while I was at it I may as well switch to some newer form of refridgerant than the R12 that is probably still in there.

YK86
04-24-2011, 10:30 AM
I got my 12a from Alder Auto which is a branch of Parts Plus. I'm not too sure what Lordco carries. I know Canadian Tire has Redtek and Walmart had Duracool I think but both cost way more than $10 a can.

dieselgus
04-24-2011, 12:46 PM
Even better. There is also an Alder just up 96th from the shop (Half the time dealing with the Lordco near the shop is a crapshoot. I do not reccomend the one just off 96th and 198th in behind the Wendeep/Hortons.)

YK86
04-24-2011, 02:09 PM
Wow, didn't think I'd be talking to someone on 3geez about Alder Auto or the Lordco on 198th lol. I stopped going to Lordco after the couple guys I dealt with for many years left the 200th and Aldergrove locations.

Alder's prices I get are consistently lower than the 30% off bs Lordco gives me so I stopped shopping for prices. The only time I go there now is if an unexpected repair is needed late at night (Metrotown store open til midnight). I take it you work in Port Kells?

dieselgus
04-24-2011, 02:58 PM
Yeah, I hear ya on late night runs up Kingsway for parts (only once, but damned handy). We get pretty solid pricing out of Lordco generally. And I usually double check on Rockauto (they will meet or beat their prices believe it or not).

For now, yeah working in Port Kells (building police cars. If you have been stopped by either a New West or Abby black and white, chances are that I built it. Whoo hoo!). Looking to move to a new shop in a couple weeks that doesn't have as much BS or an idiot owner (may the fucker go bankrupt as far as I am concerned. Can't wait to get out of there and really let people know how the place works).

And yep, probably going to switch to Alder for most of my parts needs (as rare as my care does break. Mostly slowly replacing 22 year old, 330,000km worn stuff lately)

YK86
04-24-2011, 04:03 PM
Wow, meet or beat Rockauto?? Must be a pretty big account to get prices like that. I spend about 15 to 20grand at Alder a year doing stuff on the side for people so they are pretty good to me but I'm sure it's peanuts compared to big shops.

Never seen the New West cars but I do see the black ones in Abby. That's actually pretty cool!

dieselgus
04-24-2011, 08:44 PM
Wow, meet or beat Rockauto?? Must be a pretty big account to get prices like that. I spend about 15 to 20grand at Alder a year doing stuff on the side for people so they are pretty good to me but I'm sure it's peanuts compared to big shops.

Never seen the New West cars but I do see the black ones in Abby. That's actually pretty cool!

Naw, not that big of a shop at all. But that particular Lordco is pretty slow a lot of the time so they tend to be fairly flexible. If I need a real deal one of the guys at my shop is good buddies with the manager. But shall definately head to Alder (it is closer and easier to get to anyways. Added bonus)

Yeah, the black and whites look pretty sharp. Everything in the New west fleet is a b/w, even their forensic Dodge Sprinter and the big International that pulls their disaster command centre thing.

Dr_Snooz
04-25-2011, 07:18 PM
After looking at my cans today, I'm reasonably confident you can use them without the $3 adapter. I'll verify that, but I think it's do-able.

Dr_Snooz
05-18-2011, 12:54 PM
^^^ Edit: Definitely NOT doable without the adapter. *Sigh*

ecogabriel
05-18-2011, 02:58 PM
You need to do a how-to. My brother is an engineer and gave me an earful about how propane is only half as efficient as R12. I kept telling him I'd heard it was equally as good, but he dropped the whole "I've done the math" deal on me. How do you argue with math?

Don't argue with math; just examine the problem assumptions and destroy 'em.

Incidentally, TWO engineers - one of them used to represent a U.S. firm selling industrial-scale refrigeration compressors (screw), and the other with 30+ years of experience in meat-packing industry- lectured me (long, long ago) on the industrial refrigerants of the time -ammonia and hydrocarbons. That was the FIRST time I heard of hydrocarbons being used as refrigerant.

Moreover, developing countries are pushing using hydrocarbons for stationary refrigeration (e.g. freezers) because they save on hard currency and royalties. I believe Greenpeace (for what it is worth) also promotes hydrocarbons.

Apparently, they are legal in Australia.... any Aussie that wants to enlighten us please???


I just picked up a couple cans for my mom's car. A can now runs $18.99. Plus, you need an adapter to connect your existing gauges to the new cans. PLUS, you have to pay a $10 core charge for each can. Out the door cost for two cans: $66. Yikes.

Propane keeps looking better. Incidentally, it is a recognized refrigerant referred to by the code R290.

THAT expensive???? I'll look up at my nearby Sam's club. I can probably snatch a 30lb. canister for not a whole lot more (double maybe?) so you'll be able to pass it to your offspring... think how much 30lb. of R-12 cost nowadays.... $$$$$!!!


Since we are on this topic, I converted my 90 Accord to R134a using those $40 Walmart conversion kits that everyone seems to bash. Since it was for my own car and had nothing to lose, I changed all the o-rings and drier for about $30, but filled it with the r134a without get the system vacuumed "properly". It's been over 5 years now and I have not had to fill it once and it still blows nice and cold even on the odd days it hits 100F here in Vancouver. It may not be as cold as r12 but I'm actually really happy with it, especially since it was less then $80 after tax to do it.

Now just recently, it's been warming up here and I ended up doing the same thing on the SEi for the hell of it (it's already been retrofitted but the I think the o-rings were bad and had no pressure).I didn't have time to go into the US to get more of the "usual" Interdynamics r134a so after reading up on a few AC related sites, I felt comfortable enough to grab a few cans of $10 12A (the HC based stuff that's compatible with r12 and r134a) from the local parts store plus the o-rings and drier ran about $50. I actually find the 12A blows cooler than the r134a in the 4th gen just like the tech guys on the AC said.

Anyone else find this as well?? I'm in Canada so I don't know what prices the Interdynamics r134a is recently in the US (it was $8.99 for r134a and $12.99 for Arctic Freeze last fall) but I think I'll be using 12a from now on.

If the system is not f@#k up, it should work.

The TSB for Acura to convert from R-12 to R-134 (I have a pdf copy somewhere) did not ask for flushing the old system; only evacuate old refrigerant, add new oil and an adequate amount of R-134.

There has been the discussion here (and on the web) about the kits and how R-12 residuals destroy R-134 oils (PAG) (which is true). In any event, those kits use POE oils that are compatible with both r-12 and r-134. For some reason, however, OE prefers PAG oils. In any event, the new "DEC" (double end capped) PAG oil is inmune to r-12 and neither decomposes nor absorbs humidity. Supercool is a DEC PAG oil. Someone did a nice demonstration of the difference between regular PAG and DEC PAG.

http://www.autoacforum.com/messageview.cfm?catid=20&threadid=17571

What apparently is death for A/C systems is using the "stop leak" cans (or so is what I heard)

Anyway, with hydrocarbons the oil issue is gone as I understand it works with mineral oils.

On a personal nore, I have two cans of R-12 but two cars using it. It is not enough for a complete fill-up in the 3G so if it loses too much R-12 I might have to go the hydrocarbon route.

poorman212
05-18-2011, 06:07 PM
THAT expensive???? I'll look up at my nearby Sam's club. I can probably snatch a 30lb. canister for not a whole lot more (double maybe?) so you'll be able to pass it to your offspring... think how much 30lb. of R-12 cost nowadays....

If you can get a 30LB Cyl of R134 for less than $200, yes you could make a ton of money...heck give me a quote on a trailer load where the cyl cost less than $200 per........I'll pay freight within the US.

Now a can, never said how many OZ, for $19 sound high...but if this is an 18+ OZ can, then not too far out of line....

Why does DuPont do this to us?

Dr_Snooz
05-18-2011, 06:58 PM
My Dad had the presence of mind to buy a tank of R12 just before they outlawed it. He went to use it a couple years later and it was empty. It had a faulty valve and all that precious R12 had leaked out.

gp02a0083
05-18-2011, 07:08 PM
eco what you described as the r-134 conversion is practically what they typically do at any shop. they need to evacuate the r12 and collect it to have it disposed of b/c of the whole CFC's and ozone getting chewed up , the 134 is considered to be a "greener" alternative.

my father bought a case of r-12 cans and has been selling them over the years, that stuff last i looked was like $40 or $50 a can, he was telling me that the 134 went up to about $20 a can

I've converted my last two hatches to 134 without an issue at all, i had my gold hatch for 5 years, the A/c system worked like new out of the factory and still had the original A/C pump. We also converted our 91' aerostar to 134 years ago without a problem.

As a chemist i don't believe that the DEC PAG oil does not absorb water moisture, practically everything does to a certain degree, but it might be the case where the moisture adsorption /absorption is very low.

ecogabriel
05-19-2011, 04:05 AM
If you can get a 30LB Cyl of R134 for less than $200, yes you could make a ton of money...heck give me a quote on a trailer load where the cyl cost less than $200 per........I'll pay freight within the US.

Now a can, never said how many OZ, for $19 sound high...but if this is an 18+ OZ can, then not too far out of line....

Why does DuPont do this to us?

Last time I saw those bit cylinders, they were below $200 I am pretty sure. But I have seen the news here and found the EPA ruling on the new refrigerant so I would not be surprised that everybody is raising prices in "preparation" for the change.... hey, let's make an easy buck here...



My Dad had the presence of mind to buy a tank of R12 just before they outlawed it. He went to use it a couple years later and it was empty. It had a faulty valve and all that precious R12 had leaked out.

OMFG!!! That is really really BAD luck!.:thumbdn:

ecogabriel
05-19-2011, 04:21 AM
eco what you described as the r-134 conversion is practically what they typically do at any shop. they need to evacuate the r12 and collect it to have it disposed of b/c of the whole CFC's and ozone getting chewed up , the 134 is considered to be a "greener" alternative.

my father bought a case of r-12 cans and has been selling them over the years, that stuff last i looked was like $40 or $50 a can, he was telling me that the 134 went up to about $20 a can

I've converted my last two hatches to 134 without an issue at all, i had my gold hatch for 5 years, the A/c system worked like new out of the factory and still had the original A/C pump. We also converted our 91' aerostar to 134 years ago without a problem.

As a chemist i don't believe that the DEC PAG oil does not absorb water moisture, practically everything does to a certain degree, but it might be the case where the moisture adsorption /absorption is very low.

I found the Acura service bulletin for conversion to r-134a

http://daliracing.com/v666-5/download/pdf_article/tsb/converting-r-12-ac-systems-to-r-134a95-008.pdf

As for DEC PAG , they say it not only resists R-12 residuals but also that its moisture absorption is minimal; the link I posted about someone mixing both PAGs with water tells something about it.

I woam uploading a later Honda service news with A/C info (forget about it: I cannot host pdf files...)