Older AC Just Needs A Charge

[B Jake Moran]

Like most of us that monitor the Buy/Sell Not Mine section and also browse facebook marketplace, there seems to be 2 main issues associated with many of the older cars offered for sale. 

One is incorrect replacement upholstery.  It stands out as obvious to us.  #2 is an AC system on an older car that "just needs a charge".  Just last night 2 sellers informed me what I already knew.  

They follow up that statement with "well I never have used AC, I just drive it with the windows rolled down".  Sellers clearly are intimidated by AC, and they believe, correctly so, if they take it into a qualified mechanic (which alone is difficult) the bill will be so large because of all of the unknowns - that they don't bother and now there are literally millions of collector cars from approximately 1960 to 1982 without AC despite complete systems intact. 

No one would do without AC in their modern daily driver, so why do owners of old cars cringe at the thought of correcting an AC system?

This goes for me.  Some of you know I purchased a project to work on with a young man, a 1970 Mercury Marauder X-100 with AC, it's complete, but likely failed in the mid to late 70's and was not used since.  

I don't want to be one of those guys "it just needs a charge".  Do any of you experts have advice on good reference books on AC restoration?   Why do we think there are no restoration shops that want to see AC systems?  

Can replacement AC parts that conform to modern refrigerants be sourced?  Rock Auto?  Even though I am an ex mechanic, I still confuse evaporator with condensor.  Is the evaporator the radiator near the radiator?  Or is it the heat exchanger?   
 

I'm looking tonight for a good book on Amazon.    Thoughts on the subject matter?  Real world experiences?  

 

Edited June 4 by B Jake Moran (see edit history)

[bryankazmer]

They’re both heat exchangers.
In the evaporator the refrigeration fluid evaporates - boils. This requires energy, which comes from the hot air, cooling it. 

In the condenser, the refrigerant is condensed - liquified. Energy is released to the outside air

this is oversimplified, as there are pressure effects from the compressor, but should help remember what’s going on in each

[Reicholzheimer]

YouTube is a great source of information.  I just installed an ac unit in my car and works great.  I bought a vacuum pump off ebay for $140 and freon cans from an auto store.  Changing out a compressor or condenser is easy. I would also replace all the O-rings.  Freon also comes with a color which will show leaks. 

[Larry Schramm]

The condenser is in front of the radiator and the evaporator core is in the passenger compartment.

 

To fix an old A/C system the first thing to do is to see if it is still charged.  If it is still holding refrigerant then the problem is probably electrical or maybe mechanical.

If there is no pressure in the system, then you will need to find the leak.  This is usually done by putting in a small amount of refrigerant along with a florescent dye that can be seen using a ultra violet light.  Fix the leak and many times you will fix the system.  There are some other things that probably need to be replaced along with the defective part and that includes the receiver-dryer and the orifice if the system has one.  Always on old systems look at the hoses closely for any deterioration. Especially look in areas where the hoses might run close to exhaust manifolds, etc.. Replace as necessary.

[Matt Harwood]

We no longer service the A/C systems in old cars. They don't stay fixed, no matter what you do, and then I'm married to the car forever and have to try to fix it from 2000 miles away. It's the only part we won't touch simply because it's the source of 70% of the complaints. We price the cars accordingly if the A/C doesn't work and I'm not apologetic about it. I'm usually relieved to see a car without A/C these days. It's a major headache.

 

And I, too, am sick of sellers telling me they "never used the A/C and don't know if it works." Yes you did try it and yes, you do know it's broken. It's the first thing every new owner touches when the car gets dropped in his driveway.

[Bloo]

2 hours ago, B Jake Moran said:

Why do we think there are no restoration shops that want to see AC systems?  

Because it's a quagmire, and no one is going to be happy.

 

2 hours ago, B Jake Moran said:

I still confuse evaporator with condensor.

Evaporator = Cold

Condenser = Hot

 

2 hours ago, B Jake Moran said:

No one would do without AC in their modern daily driver, so why do owners of old cars cringe at the thought of correcting an AC system?

I cringe when I see AC vents and controls in an antique, probably because I was a mechanic. It is always in the way of whatever you want to work on, it's heavy, and it's always broken or "just needing a charge". When I see it I keep looking for a different car.

 

My daily driver is not AC equipped. I really don't understand the obsession with it for antiques these days. It is my understanding that the demographic in this forum skews old. You would think people would remember how troublesome and useless these systems were back in the 70s. Apparently not. I remember. You didn't dare use them on the hottest (100F+) days or when pulling long hills out in the desert. If you can't use it when it is really hot and uncomfortable out, what good is it? 

 

2 hours ago, B Jake Moran said:

likely failed in the mid to late 70's and was not used since.  

My dad bought a 70 Marauder with 49K miles on it back in 1985. The AC worked until 2000/200K miles without ever being charged, one of the most reliable old R12 systems I have ever seen. He didn't use it much. It seems people of that generation would leave it shut off to save gas. When it quit, I took the car to work to repair it, and found the whole system contaminated and clogged. I suspect dad may have had the neighbor shoot some r134 in there. Oil compatibility can be a problem leading to sludge. It was not practical to repair it and it still doesn't work.

 

Good on you for wanting to restore it and fix it right. It will be a significant undertaking in addition to restoring the car itself. Learning and doing it yourself is the right answer. If you want to not use a bunch of modern parts, you may need to stick with R12. Others may have better and more current advice, as I have not done much AC work since the R12 days. Nevertheless, here are some of the things I think you might be up against:

 

The refrigerant was R12. New production of it is banned, and all available refrigerant available is old stock or recycled. It is very expensive. Lots of r12 systems have been converted to R134a. It doesn't work as well as R12 did (not surprisingly) in a system designed for R12. A system like this Ford one on the original R12 will blow 42 degree air on a summer day if it is not crazy hot outside. It is unlikely to make close to that on R134a. Even systems designed for R134a don't blow that cold. They make up for it by moving more air. R152a (canned air) may be another option. It has been known to work well in some R12 systems, and may be a closer match(?) than R134a. I've not used it and don't know the details.

 

The Marauder's compressor is a York/Techumseh type. Noisy and coarse, but very long lived, at least on R12. I understand these don't live long at all on R134a. If you change the refrigerant type, you will probably need to change to an Asian compressor of some sort, maybe a Sanden, and probably make some adapter brackets.

 

The hoses for R12 will not hold in R134a, a smaller molecule. I understand sometimes it is sometimes ok if the system has been running recently and the pores in the rubber are still plugged with oil molecules. That doesn't apply to you (or me) if the system hasn't ran in decades. For R134a you need new hoses.

 

You always need a new receiver dryer if the system has gone to air or if you open it. Some of the fittings on the Marauder are flare, and they are generally regarded as not good enough to hold R134a in. The receiver dryer for the Marauder was long discontinued when I looked in 2000, though you can get something close, and if you are changing the fittings anyway when you get new hoses, the adaptation problem may solve itself.

 

The evaporator and condenser will need cleaning out. In my day that was done with a flush gun and special solvent. You need all that crud out of there. It was never easy, but the solvent was a form of Freon, and is probably banned. Some cars need a larger evaporator (cold) to run R134a. The Volvo 240 is an example. I think you will be fine with the original evaporator here, but can't be 100% sure. The condenser should be ok if there's no holes, although they can get holes from rocks, or from chemical reaction if the system has gone to air.

 

Leak detectors that actually work for R12 use a flame. A flame and R12 makes Phosgene gas. Google that if you don't know what it is. Flame detectors fell out of favor. We had electronic detectors when I was in tech school, but they were much less effective, and they missed leaks. Annoying, but no big deal at the time. R12 was cheap. With the cost of R12 today, you cannot afford to miss leaks. Get some Nitrogen. At least you can leave that in overnight and see if you have any big leaks. You'll still have to diagnose any small ones somehow.

 

Other stuff: When you evacuate the system to recharge, leave the pump on it overnight. You will be rewarded with a couple extra degrees. Getting things like expansion valves and dash controls repaired is dicey. You read the RIviera forum don't you? There are plenty of threads. Check out davida1hiwaaynet on youtube (antique refrigerators). He uses a lot of R152a in systems that were once R12. I think he may have even had some car system clips, but long ago.

 

Edited June 4 by Bloo (see edit history)

[28 Chrysler]

I am one who has never tried the AC in my 1981 Jeep CJ7.

When I bought it in 2001 with 62,000 miles on it. Day one it did not have the belts on the compressor, I fingered it did not work and has been that way and will stay that way.

[West Peterson]

2 hours ago, B Jake Moran said:

No one would do without AC in their modern daily driver, so why do owners of old cars cringe at the thought of correcting an AC system?
 

 

As Matt said, they tend to not stay working very long. I have a 1940 Packard with a/c, and because the car is not used very often, I have never attempted to get the system working, even though ALL the components are there (usually the compressor is gone). The cost to get it working will involve an expert who will not screw up the "impossible-to-replace" compressor. Once working, it may get used once per year, and the following year, it may not work again. Why spend the money unless/until I start using the car regularly and on July/August tours???

[B Jake Moran]

West - all good points. Well, everyone has made good points.  I just can’t see hanging the AC parts back on the car for correct looks. AND I do occasionally see ads selling old cars that do state the AC blows cold.  
 

As to trying to make do with a mix of old and new parts I would think we need to replace every single part.  They all look well used.  

[Frank DuVal]

2 hours ago, Bloo said:

original R12 will blow 42 degree air on a summer day if it is not crazy hot outside. It is unlikely to make close to that on R134a. Even systems designed for R134a don't blow that cold.

Ha! 🤣  You can get 134a designed systems down to freezing the evaporator! That's 32°F or below.  I do agree most converted systems do not....😡  But my '84 F-150 does. Quite surprised at that, but maybe the small cubic feet of the cab helps. 

 

 

I like my AC to work. A heart issue will do that to you if you live where it gets to 90+°F and 90% humidity! 

 

 

 

2 hours ago, Bloo said:

R152a (canned air) may be another option. It has been known to work well in some R12 systems,

There is a Corvair owner in Arizona who uses the R152 canned air (not all canned air is, though) with great results. Of course it is a dry heat.🤣 I am going to try this some day.

 

2 hours ago, Bloo said:

The evaporator and condenser will need cleaning out. In my day that was done with a flush gun and special solvent. You need all that crud out of there. It was never easy, but the solvent was a form of Freon, and is probably banned.

Yes it is. There are new flush solvents on the market, so not an issue. Some newer condensers are impossible to flush, just replace. But the antique ones for R12 are usually single pass and flushable.

 

2 hours ago, Bloo said:

Leak detectors that actually work for R12 use a flame.

The newer electronic types are fine. I've been using them for 30 years.

 

I agree on using Nitrogen to test for leaks, it also helps flush moisture out. Moisture big enemy. I agree on leaving vacuum pump on overnight, or at least leaving the system under vacuum overnight (if you do not want to leave pump running unattended) and start the pump the next day for a few hours. And of course if the system looses vacuum overnight, go find the leak(s).

 

You can put a heat lamp on a receiver dryer while under vacuum to dry the desiccant. But, you cannot change the internal filter, which is probably clogged now.... so replacement is the option. Or, cut it open, figure out how to change the filter media, dry the desiccant and tig weld back together... The re-dry the desiccant. Replacement sounds easier.😉

 

 

 

[Dave39MD]

Does anyone have experience using R134A in a A-6 compressor equipped vehicle that started life with R-12? 

 

thanks

 

Dave

[Larry Schramm]

For finding leaks, use the dye that can be seen with an ultraviolet light.  Easy & high success rate.

 

Here pick one depending if the system is open (with a hose not connected) or all closed up and has been evacuated.

 

https://www.google.com/search?q=ac+refrigerant+with+uv+dye+kit&client=opera&hs=y0w&sca_esv=b061e2632347ae6b&sxsrf=ADLYWIIHFNh8T7QMbdOTCop0EbKRg0HrlA%3A1717521703225&ei=J01fZs-2DdamptQP9fmU2Qw&oq=a%2Fc+dye&gs_lp=Egxnd3Mtd2l6LXNlcnAiB2EvYyBkeWUqAggAMgoQABiwAxjWBBhHMgoQABiwAxjWBBhHMgoQABiwAxjWBBhHMgoQABiwAxjWBBhHMgoQABiwAxjWBBhHMgoQABiwAxjWBBhHMgoQABiwAxjWBBhHMgoQABiwAxjWBBhHSPEjUABYAHABeAGQAQCYAQCgAQCqAQC4AQHIAQCYAgGgAgWYAwCIBgGQBgiSBwExoAcA&sclient=gws-wiz-serp

 

https://www.google.com/search?client=opera&q=a%2Fc+dye&sourceid=opera&ie=UTF-8&oe=UTF-8

Edited June 4 by Larry Schramm (see edit history)

[ABear]

5 hours ago, B Jake Moran said:

No one would do without AC in their modern daily driver, so why do owners of old cars cringe at the thought of correcting an AC system?

Actually, I HAVE done this with a "modern vehicle" due to the extremely high cost to repair it..

 

Have a 2013 F250 with the dreaded evaporator leak, truck was just 5 yrs old when the compressor failed in spectacular fashion complete with a large cloud of smoke from the serpentine belt when the compressor locked up.. All out of warranty.. Spent $800 for a rebuilt compressor and a refrigerant refill.. The next summer, the AC refused to cool, mechanic came back with it was low on refrigerant, they added refrigerant plus dye but was not able to find the leak.. The next summer, no AC again.. Yep low on refrigerant and once again, leak was not found.. The fix? Yep, the leak is in the evaporator coil (a common issue with 2011-2015 yrs) which requires entire dash plus steering column to be removed just to get at it.. A $2K+ repair for a now 7 yr old vehicle with nearly 140K miles..

 

Reality is for collector cars, most collectors will not be driving enough to warrant the cost of having the AC system repaired and maintained by professional AC mechanics and even if they did repair it, it won't stay repaired.

[TAKerry]

Now that the heat of the summer is starting finally a relevant thread! Hopefully I will be finishing up the restoration of my 79 Trans Am before the summer is over. Everything is as near stock as possible. I have been on the fence with the A/C. One hand says 'fix it the way it should be and make it work properly'. On the other hand I figure, IF its THAT hot I just wont bother driving it! When the shop installed the motor in my 77 Trans Am they put all of the A/C components in but no belt and did not hook anything up. It was the same story as mentioned above. He didnt feel like fooling with it, didnt know what was going to be involved, not worth the effort. I was fine with that and for the last 6 years or so have lived without it. Besides the T tops are off all summer anyway. Hence why I am on the fence with the '79. The stock compressors are know for slinging oil, which Im not keen on but I can get a new compressor that is half the weight that bolts right in. The cost is the same as a rebuilt nos unit. Even with the rebuilts I have heard tales of the infamous oil sling. Still on the fence but will most likely go for a new compressor and try to get it right this time.

[Andy J]

I don't know anything about automotive AC systems.I wish I did because I could have saved a small fortune in repairs the last 50 years.I do know this from experience: if a car has been sitting up for a couple of years,the AC isn't going to work just by charging the system.Even if the car has been running and the AC doesn't work,it usually means there is a major problem.People who think,"it just needs to be charged up" are full of s--t. It ain't NEVER that easy.

[TexRiv_63]

35 minutes ago, Dave39MD said:

Does anyone have experience using R134A in a A-6 compressor equipped vehicle that started life with R-12? 

 

thanks

 

Dave

My 1963 Olds Starfire had the original factory a/c system. It had been converted to R-134a before I bought it and was still sealed but did not cool well. I had a shop evacuate it, check for leaks and fix a couple and recharge. It worked for 9 years with no additional work although it did not cool as well as R-12 since the stock condenser was still in place.

[JACK M]

I have commented in the past.

No AC is a plus for most of these old cars.

As noted, if one goes to the trouble and expense to get it working, you will most likely be making that an annual thing.

[TexRiv_63]

I live in Texas so if you have a car equipped with a/c you really want it to work. I have owned one car (63 Starfire) which still had the stock system converted to R134 and it worked for 9 years. I had one (63 Riviera) that I converted the factory a/c to Vintage Air, and one that came with VA installed (67 GTX) My 66 Dodge wagon had factory DUAL a/c, I converted the underhood stuff to new R134 but reused the two evaporators and controls. My 60 Buick does not have a/c and that means I can't use it much all summer so I am trying to figure out a conversion.

 

On your Mercury the main question you have to answer is how important factory appearance is versus actual useability. If the stock system has been open to the elements or the controls do not work it will be a real pain to fix back to original.

[Reicholzheimer]

Go to Classic Auto Air website and read    R134a CONVERSION KITS   They also supply Compressor, expansion valves, hoses, condenser and advise.  You can do all the work yourself.   

[76 Caddy]

I like driving with the window(s) down.  The Silverado's a/c quit in '15 due to a bad shaft seal.  The Brougham hasn't worked since I've owned it and since it only gets 10-12 mpg, I hate to see what it would get with a/c.  The Seville was already converted to R134 when I bought it, however it leaks down over the winter but will last all summer when charged, but I haven't charged it in the last couple of years.  The Impala has been converted but I haven't started it yet, so it's still a mystery.

 

Tim

 

     

[ABear]

2 hours ago, Dave39MD said:

Does anyone have experience using R134A in a A-6 compressor equipped vehicle that started life with R-12? 

 

thanks

 

Dave

R134A has less heat capacity, so using R134A in a system originally designed for R12 is a compromise at best and may not have as much cooling capability it had with R12.

 

From HERE

 

"Equipment built for R-12 will be sized a bit too small compared to equipment built for R-134a. In order to do the same job, an R-134a system will need a larger compressor and larger heat exchangers. As a result, a system that is retrofitted from R-12 to R-134a will have lower capacity (run longer) and will probably develop higher head pressures (not enough condenser area)."

 

Not saying it can't be done, but in most cases it will not work as well as originally designed..

 

This may not affect all vehicles the same, some may have had slightly oversized OEM systems and some may have marginally sized OEM systems so you toss the quarter and see what you get for results.

 

By the way R12 while it is no longer being manufactured, it is still out there in new unused 30 lb cans, they pop up for sale regularly on craigslist for sale. Not saying it is legal to buy/sell it but folks are doing that.

[Pfeil]

2 hours ago, TAKerry said:

Now that the heat of the summer is starting finally a relevant thread! Hopefully I will be finishing up the restoration of my 79 Trans Am before the summer is over. Everything is as near stock as possible. I have been on the fence with the A/C. One hand says 'fix it the way it should be and make it work properly'. On the other hand I figure, IF its THAT hot I just wont bother driving it! When the shop installed the motor in my 77 Trans Am they put all of the A/C components in but no belt and did not hook anything up. It was the same story as mentioned above. He didnt feel like fooling with it, didnt know what was going to be involved, not worth the effort. I was fine with that and for the last 6 years or so have lived without it. Besides the T tops are off all summer anyway. Hence why I am on the fence with the '79. The stock compressors are know for slinging oil, which Im not keen on but I can get a new compressor that is half the weight that bolts right in. The cost is the same as a rebuilt nos unit. Even with the rebuilts I have heard tales of the infamous oil sling. Still on the fence but will most likely go for a new compressor and try to get it right this time.

Live with a little weeping, the factory service manual says this is normal. Buick/Chevrolet Corvette and some other GM products provide a shield to keep the oil off the engine, underside of hood etc.

If you are replacing the OE compressor beware of the new type because you will also need a high pressure and low-pressure switch to be installed in the A/C lines. This is because the new lookalike compressor has NO oil sump so if you lose freon and don't have a low-pressure switch to turn the compressor off you will burn up the compressor. On the old R12 A6 you could lose freon and run the compressor for as long as you wanted and never hurt the unit.  

[Pfeil]

3 hours ago, Dave39MD said:

Does anyone have experience using R134A in a A-6 compressor equipped vehicle that started life with R-12? 

 

thanks

 

Dave

Yes! I bought my 63 Pontiac Catalina about ten years ago and it had been converted. The first thing I did was to go through the system and return it to R12. It was designed for R12 and that's the way it shall be.

 No problem for ten years now. All you have to do is run the system once a week to get the freon/lubricant to get to the seals and all is good. That goes for your home's A/C, once a week for 20min. even in winter.

FYI, I've only charged my 69 Pontiacs A/C once (1992) because of an oil drain issue with the evaporator I had to remove and repair. I've owned the car since new and coming up on 56 years.

[B Jake Moran]

6 hours ago, ABear said:

Actually, I HAVE done this with a "modern vehicle" due to the extremely high cost to repair it..

 

Have a 2013 F250 with the dreaded evaporator leak, truck was just 5 yrs old when the compressor failed in spectacular fashion complete with a large cloud of smoke from the serpentine belt when the compressor locked up.. All out of warranty.. Spent $800 for a rebuilt compressor and a refrigerant refill.. The next summer, the AC refused to cool, mechanic came back with it was low on refrigerant, they added refrigerant plus dye but was not able to find the leak.. The next summer, no AC again.. Yep low on refrigerant and once again, leak was not found.. The fix? Yep, the leak is in the evaporator coil (a common issue with 2011-2015 yrs) which requires entire dash plus steering column to be removed just to get at it.. A $2K+ repair for a now 7 yr old vehicle with nearly 140K miles..

 

Reality is for collector cars, most collectors will not be driving enough to warrant the cost of having the AC system repaired and maintained by professional AC mechanics and even if they did repair it, it won't stay repaired.

This is the poster child story for AC problems.  Plus, you note that most collector cars, with or without AC, are driven in spring, fall, not so much in intense heat and humidity.  If I had a pre AC car, I would drive it from April to early November, because driving it in all seasons was part of the appeal and authenticity of the car.  BUT, I remember AC in the 70's with R12 kicking butt and being very cold.  

[B Jake Moran]

5 hours ago, Reicholzheimer said:

Go to Classic Auto Air website and read    R134a CONVERSION KITS   They also supply Compressor, expansion valves, hoses, condenser and advise.  You can do all the work yourself.   

Thanks for the tip!

[CChinn]

I drive my 2 pre-war cars all yearlong - spring, summer, fall and winter. No AC or heat from the factory. Windows down and cowl vent in the summer and windows up, layered clothing and lap robe in the winter if necessary. 

Edited June 5 by CChinn (see edit history)

[BobinVirginia]

10 minutes ago, CChinn said:

I drive my 2 pre-war cars all yearlong - spring, summer, fall and winter. No AC or heat from the factory. Windows down and cowl vent in the summer and windows up, layered clothing and lap robe in the winter if necessary. 

Nice!! They were meant to be driven. Enjoy them when you feel like it despite weather!! We only live once 

[TTR]

50 minutes ago, CChinn said:

I drive my 2 pre-war cars all yearlong - spring, summer, fall and winter. No AC or heat from the factory. Windows down and cowl vent in the summer and windows up, layered clothing and lap robe in the winter if necessary. 

Same here, except one of my "vintage" cars doesn't even have windows and one, in spite of being a convertible, has almost 70 y.o. factory A/C (fully rebuilt/restored by me over 25 years ago and still working).

 

I'm also currently rebuilding/restoring a factory A/C system in a 64 y.o. client car and have two 50+ y.o. Italian GT cars on the waiting list for same (likely to be done sometime next winter).

 

 

Edited June 5 by TTR (see edit history)

[Larry Schramm]

I may jinx myself, but our '76 Corvette still has working AC.  The only thing that has gone wrong with it was a rubber hose went bad.  Fixed the hose and all is well.

[TexRiv_63]

21 hours ago, ABear said:

R134A has less heat capacity, so using R134A in a system originally designed for R12 is a compromise at best and may not have as much cooling capability it had with R12.

 

 

This is true but the situation can be improved by switching to a new condenser designed for R134 even if the other components are retained.

[ABear]

1 minute ago, TexRiv_63 said:

This is true but the situation can be improved by switching to a new condenser designed for R134 even if the other components are retained.

 

Never said it couldn't be done even with all OEM parts, just said it is a compromise, as is adding a larger condenser will be without changing out the evaporator and compressor to the proper sizes..

 

Can it be made to work with changing the condenser to a larger size?

 

Sure, but it is still a compromise at best since the OEM evaporator will still be undersized and may not be as efficient with R134A.. In other words, perhaps a slight improvement but not as good as it would be with R12.

 

I have owned early 70's vehicles that were designed for R12, even with R12 they barely were able to cool the car. The systems in those cars most definitely would not "improve" with a simple change of a larger condenser, nope, those NEED a total system redo to make them work well even with R12. I have also had a vehicle built in 1997 which was designed for R12, it would freeze you out in 10 minutes even on a 100F+ Summer day with it's original charge of R12 8yrs later when I traded it in.

[Ben Bruce aka First Born]

1 hour ago, ABear said:

Never said it couldn't be done even with all OEM parts, just said it is a compromise, as is adding a larger condenser will be without changing out the evaporator and compressor to the proper sizes..

 

Can it be made to work with changing the condenser to a larger size?

 

Sure, but it is still a compromise at best since the OEM evaporator will still be undersized and may not be as efficient with R134A.. In other words, perhaps a slight improvement but not as good as it would be with R12.

 

I have owned early 70's vehicles that were designed for R12, even with R12 they barely were able to cool the car. The systems in those cars most definitely would not "improve" with a simple change of a larger condenser, nope, those NEED a total system redo to make them work well even with R12. I have also had a vehicle built in 1997 which was designed for R12, it would freeze you out in 10 minutes even on a 100F+ Summer day with it's original charge of R12 8yrs later when I traded it in.

 

 1997??   I thought R12 was banned in new cars in 1994.

 

  Ben

[TTR]

1 hour ago, TexRiv_63 said:

This is true but the situation can be improved by switching to a new condenser designed for R134 even if the other components are retained.

AFAIK (& have experienced firsthand), just switching the condenser to a aftermarket/modern R134A design style while retaining all other R12 intended OEM components is negligible at best to provide any efficiency improvements.

There are other, more beneficial improvements one can introduce, but some will require more work and in some cases may require deviations from authenticity/originality (just like shown in TexRiv_63 images).

 

[ABear]

8 minutes ago, Ben Bruce aka First Born said:

1997??   I thought R12 was banned in new cars in 1994.

R12 was "phased out", meaning remaining new stock could be used until gone, once gone could not buy any more..

 

96 was official for auto manufacturers to use up what they had, but you need to understand that vehicle manufacturers start building new models in the yr before..

 

So, technically my 97 was actually built at the END of 96 but it was MODEL YEAR 97..

 

Basically Model yr 97 was at the end of R12 use in new autos.

 

One could however still buy brand new 30 lb R12 cylinders for a few yrs after 96 without a license, I did and still have it. If you have a license you could still buy new old stock for many yrs after.

[MarkV]

My 82 Imperial has the original system and compressor and sat for 20 years. Replaced the orings and converted to 134 a few years ago and it still runs great! 

[Reicholzheimer]

18 hours ago, MarkV said:

My 82 Imperial has the original system and compressor and sat for 20 years. Replaced the orings and converted to 134 a few years ago and it still runs great! 

You made it sound too simple!