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R134 back to R12 on 1960's and 1970's Cadillacs

Started by Scot Minesinger, June 24, 2018, 08:13:51 PM

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Scot Minesinger

Many have converted their original R12 Cadillac to r134.  Now that r134 is bad for Earth, I am considering going back to R12 on some Cadillacs converted to r134.  I have purchased a full never opened 30lb drum of r12.  I think I will get the Robin Air machine and devote it to r12. 

What does it take to go back to r12?  Guessing remove and thoroughly clean all components and use the correct r12 mineral oil - what else and how thorough of a cleaning is required?
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

chrisntam

Greg would be the authority here, but I'll chime in.

Get "all" the PAG oil out of the system, how that's done, don't know.  I think the compressor would be the challenge.  My understanding is that the two oils don't play well together.

Did the POA get "adjusted" for 134?  If so, adjust it back for 12.

New hoses?  New expansion valve (their inexpensive) and a new drier and let us know how it goes.

Where's Greg?

1970 Deville Convertible 
Dallas, Texas

bcroe

Thank goodness I never tried R134, have run some propane-butane
on a stock system.  Still have R12 on the shelf, but think it best to
change to the high density hoses before doing any more.  Bruce Roe

Dan LeBlanc

That's the nice thing about Ester oil - it's compatible with R12 or R134a  ;)
Dan LeBlanc
1977 Lincoln Continental Town Car

"Cadillac Kid" Greg Surfas 15364

Bruce,
I never thought I would say this but it seems you are thinking along conventional lines with your choice of refrigerants. The Hydrocarbons are main stream now. I have actually gotten licensed for R-290 and 600, Propane and IsoButane.
That aside, the most obvious item on the list of things to do when changing back to R-12refrigerant is to return all refrigeration and control system components back to their original R-12 configuration.
On the issue of system flushing and cleaning, that can get messy.  Initially when changed to R134a any residual Mineral oil that was not removed has by now been converted (by 134a) into a semi-gelatinous mass somewhere in the system. If ALL of that is not removed by scrupulous cleaning with a dedicated refrigerant solvent such as RX-11 all bets are off as to what will be formed when the new refrigerant/oil (R-12 and Mineral or POE) mix is installed.
Yes, the compressor would need a thorough internal cleaning as well which if done for cleaning purposes would essentially mean disassembly and re-sealing the casing.  If however the system was run for any time at all under high ambient temperatures you will probably find the excessive temperatures the compressor valves experienced have taken their toll and the reed valves will have lost some of their temper and the compressor itself lost a bit (varying amount dependent upon several things) of its efficiency and thus capacity. Soooooooo, changing the compressor would be a reasonable expectation.
That brings us back to the original issue.  Are you changing back to R-12 because the system has lost the 20% capacity R-134a results in or are you concerned about the availability of 134a?  R-134a production should not begin to decline until 2024 when new commercial refrigeration systems will no longer be produced that use it. That's six (+) years.
Why not consider going to HFO 1234yf?  That is the refrigerant being utilized in new car production.  It is "Today's" refrigerant of the future.  Retail price of $1770 for a 10 pound cylinder and its use requires a substantial (several thousand dollars) investment n equipment.
Hang on, the ride is not over.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

fishnjim

I wouldn't put this in writing if I was doing this for fear the environmental police were watching... 
R-12 is not "good for" the Earth either, so to speak..."worse than" 134a.   Funny, but other "protocol" countries can make and use R12, but not here?   
134a we were told was "good" for ozone, until they "worried" about warming potential.    What will they demand next?   
1234 is a "monopoly" and the price reflects it.   
If you read the history of all the refrigerant gyrations, you'll get whiplash.   And here we are back talking about 12???   Full circle.

Eric DeVirgilis CLC# 8621

A Cadillac Motorcar is a Possession for which there is no Acceptable Substitute

bcroe

#7
Quote from: "Cadillac Kid"  Greg Surfas 15364
Bruce,  I never thought I would say this but it seems you are thinking
along conventional lines with your choice of refrigerants.

Why not consider going to HFO 1234yf?  That is the refrigerant being utilized in new car production.  It is "Today's" refrigerant of the future.  Retail price of $1770 for a 10 pound cylinder and its use requires a substantial (several thousand dollars) investment n equipment.  Greg Surfas 

I see this as a part of the "New Deal" being offered in recent decades. 
Used to be a product was offered at the lowest price possible so many
could and would purchase it.  Lately the plan is to monopolize a market,
by patents, or buying out the competition, or legislation pushed by those
ever present lobbyists, then massively escalate the price and cancel
the established benefits.  Works well on stuff considered essential, like
food, or drugs, or banking, or refrigerant.  Profits pour in. 

The ND is in direct conflict with my lifelong process of avoiding gouging. 
There is a limit to how many hats one can wear in one lifetime, already
doing energy conservation, transmissions, fuel injection, dance, and
many phases of electronics here.  Not anxious to take on refrigeration
too, just want to put in basic parts and run basic systems.  R12 seems
to fit, will continue as long as I have it, the propane-butane is a tested
alternative.  Bruce Roe

2manycars

I'm tearing down the AC system in my 64 CdV right now. I'm planning on sticking with R12. a friend of mine with a body shop still has it. I'm pulling the entire system out and having it ALL rebuilt / cleaned / flushed as necessary. New heater core too. Totally inoperative system for lord knows how many years before I got the car 2 years ago. At least the control head, servo, and transducer are working.

Trying to get in touch with Original Air Group about it...
1964 Coupe de Ville
My Current Projects:
1957 Ford Thunderbird
1967 Chevrolet Camaro RS Convertible
My Special One:
2001 Chevrolet Corvette Convertible (bought it new)

cadillacmike68

Yeah, the euros have been on R134's case for years. but what do you thing R12 got the boot in the first place.

Don't waste the money. Save that drum of R12 for your next project car or sell it!
Regards,
"Cadillac" Mike

Scot Minesinger

Thanks - all fantastic information:

2024 is when r134 will be more difficult to buy, OK there is some time.

My reasoning on going back to r12 was that if r134 was going to be as difficult as r12, then heck might as well enjoy the 20% extra capacity. 

So goes without saying put the car back to r12 components, clean it real well and expect a compressor failure, hopefully not but expect it.

I have all my licenses for refrigerant, as the parts stores will not sell me a 30lb drum of r134 without it.

There is no one in this area who works on r12 systems, so I could make a go of it and earn some extra cash??

Thanks for the input.

Scot
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

cadillacmike68

Scot,

Difficult as in Expensive. We won't be there for quite some time.
Regards,
"Cadillac" Mike

"Cadillac Kid" Greg Surfas 15364

Scott,
I think what will happen before 123a becomes scarce is the compressor rebuilders will get stricter on their warranties and they will determine ther abuse A-6 compressors get with 134a will either up the prices for the rebuilds or increase the costs and scrutiny of the cores.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

fishnjim

It's wild speculation at best to arrive at any conclusion in this field.  It's been evolving for decades now and will continue to be politicized.   I've followed it.   One of my side responsibilities, was to make and blend refrigerants for R&D, and we did the engineering for plants, and it was a journey.   I'm glad I'm retired and not bothered.   The '58 is non-A/C, so I don't have worry.
12 is OKed for a number of uses, and it's available in large quantity, but all made in china mostly, due to the protocol.   We used to keep a ton cylinder on hand. 
The small 20 lbers and under are where you get into EPA paperwork, training, and capture equipment requirements.   The auto AC only uses 1-2 lbs, so they pick on that instead of the large uses?   Probably the tail wagging the dog but something they can regulate and enforce and pass on the costs.   
I can't say for sure they know what the ozone hole does or doesn't do.   But it just so happens, it started to close after the bans.   It all sounded good, but not conclusive to my knowledge.  They proved the reduction mechanism, but no way to confirm on large scale experiment.   I'm sure the "E" people will dispute anything rational.   Recently, there's been an uptick in CFCs in the atmosphere and they're all bent out of shape about it.  So that may trigger something.   I'd bet money Trump or Pruett aren't interested.
The 1234yf was taken to US court and Honeywell/Dupont patents were recently upheld.   So the market is captive and I haven't kept up or seen anything to know if it'll be licensed.  For now there's one legit source, so they can charge what they can get.   The counter fitters will come, if it gets pricey at volume.   When that substitute first came up, Mercedes had issues with fires, and did not accept it, so it's not an end all by any means.  There was US legislation to mandate it,(protect Honeywell in state investment) but I haven't seen that outcome.   I sent a note to Senator to vote no.   Back in eng school, we were told r12 was one of the best refrigerants, based on thermo properties, and that hasn't changed, just how it's perceived.   I know in commercial units, when the shift to 134a came, the unit had to be upsized about 20% to provide the same output.   There's nothing wrong with 134a either, it's relatively inexpensive to make, lots of capacity, not an ozone issue but some GWP, but the market was so disjointed for so long, it got a bad wrap too.   There were lubrication issues early on, etc.   There are a few other blends, non-flammable, whose numbers escape me, that will work so don't throw the baby out with the bath water just yet.   
The smart play would be to use CO2 then there's no release/safety/environment issues.   I've never understood why the auto guys didn't switch to sealed hermetic systems like in refrigerators.  Just needs a magnetic drive under the clutch.   They're not going to leak - ever.   But they won't make money selling parts and service or have anything to regulate either...

Dan LeBlanc

From what I've been reading from several sources, R134a will continue to be produced, although demand will decrease.  There will be no retrofitting of R134a systems with HFO1234yf and R134a will continue to be produced for servicing those systems.  Manufacturers of new automobiles will not be allowed to install R134a systems beyond the 2020 model year.  There will be no mandatory reductions in production and imports of R134a like we saw with CFC refrigerants (R12 and R22).

I think it would be very likely that you'll see R134a being produced for many years to come.
Dan LeBlanc
1977 Lincoln Continental Town Car

"Cadillac Kid" Greg Surfas 15364

Dan
FWIW HFO-1234yf IS intended as a replacement for R-134a
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Dan LeBlanc

So it's probably the way of phasing out R134a without actually phasing it out - drying up the demand for it so that it's no longer economical to produce.  Given the cost of 1234YF, I can't see anyone in their right mind retrofitting an R134a system with it unless the price of the refrigerant is comparable to R134a.

It will be interesting to see how it plays out over the course of the next 10-20 years.
Dan LeBlanc
1977 Lincoln Continental Town Car