My 65 Mercury has factory air and since the system works with heat its time for it to blow cold air,going to convert to modern refrigerant so would it be best to use the original compressor or replace with a modern version. Not worried about originality but want it to work its best.
Many R12 to 134a conversations have been done. I’ve never heard of anyone changing a compressor. Other components, yes.
When I did my 60 T-Bird I updated to a modern rotary compressor and mounted it to the stock plate with an adapter, got the adapter from one of the Thunderbird parts vendors but don't remember which one. I replaced the hoses, dryer and converted it to 134A. The rotary compressor is more efficient and uses less power than the old piston compressors.
Adapter is available from multiple sources. This one is from a good vendor (I have used their products) and is about 1/2 the price of some of the other venders. https://www.oldairproducts.com/product/40-608c-compressor-bracket-york-to-sanden-adapter-plate. Lots of issues to consider in going from R-12 to R-134A. The R-134A molecules are smaller and sometimes leaks out of the the old R-12 hoses. Compressor oil is different. The 56 year old AC parts "might" be worn out. Different expansion valve is needed. A 3 pass condenser is recommended. - Way too many years since I last looked into it, so I can not provide specific web links. I have chosen to go with all new aftermarket in the 4 AC installations (Old Air, Arizona Mobile Air, Vintage Air and Speedway) that I completed. 1971 IH (factory AC was junk), 1975 IH (no factory AC), 1986 Ford (factory AC was junk) and 1962 Volvo (never, ever had AC). Russ
R134A operates at a higher pressure than R12, but I too made the change with an R12 compressor and had no issues in an OT pickup. I believe I had to change the valve that controls flow in the lines (sorry-forgotwhat that’s called), but you can look it up. John
My suggestion is that since you have R12, find the problem, if it is a leak fix it and stay cool. Make sure you have correct oil for old system and add accordingly.
A/C clutch did not kick on but need to see if I am getting power to it first but if the clutch is bad then it might be easier to adapt a newer compressor so are they made to still use R12.
The clutch makes a big difference on any compressor. A few years back,,,my sons OT Mopar truck started giving trouble . After the first cycle,,,,the clutch would not re engage ,,,,,like it was low Freon . The clutch would heat up,,,,,and dead after a few minutes . Replaced with a used clutch,,,,,but checked it good first . Those things are metal to metal inside,,,,,,after years of use,,,,,there is a lot of wear . Anyway,,,,,,we cleaned the wear pattern up some ,,,,,shimmed it to correct clearance. After that,,,,it was so cold,,,,your glasses would fog when getting out of the truck . Man,,,,those old systems work pretty good,,,,if they are right . Fix the problem,,,,,and it will probably work just fine with the old compressor. Tommy
This is true. The R12 will cool more efficiently and much better than the 134A. I've done this twice, and like above, just add the oil, add freon and go. IF you can't find the leak or too hard to get to, try the leak stop-i know there's a lot of haters out there but it does work for small leaks, i'm running 2 with it now and have been for years.
Clutch on a York compressor is easy to change. Take off the nut, screw a bolt in, it pops right off, don’t even need a special tool. I think the bolt is a 7/16, but it’s been a while since I did one.
I do not know what I done wrong last night but I got power going to the clutch and it does work and the compressor felt good while turning so time to find the correct 3 groove crank pulley and put a vacumn on it and charge it up,only the compressor was disconnected to remove the engine for a rebuild and from what I could tell there is no O rings and only a metal to metal seal so I should be good. It was missing the crank pulley when I bought it and only could find a two groove to at least run the p/s pump so time to start looking and maybe I can get cold air by the end of summer and where can I get compressor oil for R12.
You are probably right. I remember I had an odd one in the bolt box and used it the last time I did one. As to compressor oil, they make one that is compatible with both R12 and R134a. I've seen it at the parts house before. Posted this last night, but for some reason it didn't show up.
To use R-134a you do not want the R-12 oil (mineral oil). You need what is called either Ester oil or PAG oil. Most conversion use ester oil. Mineral oil is not miscible in R-134a. Your old York compressor, if still using that doesn't require oil in the refrigerant. It is the only compressor that does not circulate oil with the refrigerant. York has separate oil sump for the compressor. kinda like a small Briggs and Stratton engine. So there is also the condenser question and hoses. R-134a needs a better new style serpentine condenser vs the old R-12 tube and fin type - for maximum cooling results. Tube and fin will still work, just may not be as cold as possible. Hoses leaking is negligible and I would not change hoses if your current hoses are good. The R-12 thermal expansion valve (TXV) will work with R-134a as well, just not at maximum performance. TXV tuning for R-134a is just not that critical. I have used 2 old 60s underdash evap units, running R-134a with tube and fin condenser in one case even, and had real nice cool air. If you change to a sanden compressor you do need to add oil to the refrigerant loop system. Not necessary for York compressor.
jyj; You will be happier w/the R12 compared to the R134a. Easier colder. Only issue is R12 availability, which = price. If you have it( lots? ), or access to more @ very reasonable prices, that'd be my choice. It's still available in 30lb containers, last I heard, probably from Mexico where I think there is at least 1 mfgrg plant. EPA rules are part of the Idiocracy we're forced to live in, but since they - well, no, I'm not going there. There is, of course, always Propane as a refrigerant, but you might want to know what you're doing prior to utilizing it. FWIW, spend the time/energy/$$$ to make sure you don't have leaks, or moisture in the system. & you should know, that the oil that gets spread around & pumped thru the system is ~ 50% of the seal to prevent the freon from leaking thru things. Pay attention to the a/c comp crank seal, as they are a PIA & leak quickly if not run very often(set a/c to run when you have the defrost on, like the newer cars do. If you can, get & install bronze seals w/bellows instead of the cheap carbon seal. Expensive, but worth it many times over. This isn't hard, nor rocket science, but does require attention to detail.). I'm a big fan of using nitrogen to dry out the system & also for leak checking w/a touch of freon + a sniffer, then vac it properly, & I mean Properly before you charge it. EPA rules not-withstanding, my concern is leaks = lost $$$, also frustration(s) when the systems don't work well & have to be fixed, ad nuseum. I hate doing things more than once, iffen it's preventable. Marcus...
Hello, When we bought our next hot rod project, it was fairly complete, but just needed a ton of work to get it to our standards. Drivability, safety and stopping were the most important things we needed to take care of in the rebuilding process. There were too many things wrong, but the initial purchase gave us a good starting point. My wife and I never had a car or hot rod that had A/C. So, this 1940 sedan delivery had a complete A/C unit on the 327. It was a York upright compressor. At the time, the rotary or axial compressors were not available for hot rod A/C conversions or installations. So, something is better than nothing. It worked, made the inside cave cold enough that people wanted to just get in the back to roll around on hot days. But, the upright York Compressor had problems and several A/C experts had a heck of a time figuring it out. The cost of a new, York Compressor was not in the cards, so a fix was in the works. Once it was sorted out, it worked fine and I had to recharge it when necessary. The York compressor had problems, but it was the one we had and we worked with A/C experts to keep it running correctly. My wife thanked me many times over as it was a mandatory thing for her to have when going places in the 40 sedan delivery, either with me or by herself. Jnaki All of the A/C problems were finished when we sold the sedan delivery. But, our next car had a new rotary or axial compressor for better efficiency, with less problems. Boy, was it ever more efficient and super cold. Not one problem for the next 6 years. These days, there are plenty of companies that have the complete changeover systems that have the smaller, but more efficient axial compressors. Plus, they do not take up much space in any compartment. They work well, too. If you are planning on keeping your old car, it might be cost efficient to make the changeover to a new axial compressor system with new hoses and accessories. As old as the original system is concerned, it might not be worth it to continue hassling with it in the long run. Plus, a new axial compressor system is much more efficient. YRMV
The Jalopy Journal
