Starting over help. Fix and back to R-12

Discussion in 'The Big Chill' started by djonesutah, Feb 11, 2012.

  1. djonesutah

    djonesutah Well-Known Member

    65 skylark fact A/C

    I simply added 134A and oil to my system that had no pressure at all coming out of restoration, and replaced my expansion valve because of broken tubing. Turns out I had a significant leak in the system at the dryer connection. But, the A/C air wasn't very cold even at the first charge with 134. I know there is a lot more that should have been done. I ran it anyway through the summer. My compressor failed. It wasn't that the compressor itself seized up. Instead, the bearing on the front for the pulley was destroyed...actually locked up. It did have oil in the sump. The compressor seems fine with the clutch disengaged. I think the clutch mating surface is ruined. I expect seals are ruined because it got really hot.

    I want to fix the A/C system and go back to R-12 I've pulled the compressor and the dryer. I have blown acetone through the remaining system to get out any oils. I also did the same to the dryer.

    My questions are:

    What do I do for a replacement compressor? I want it to look like near original, though I don't really care if the A6 compressor is the exact P/N that came with the car. Woudl it be recommended that I go to a scrap yard and pull one from a car that seems to turn OK by hand? Any compressor froma GM that looks to be the right dimensions and fittings? I see other posts here recommend I don't buy a rebuilt one because of poor quality? I assume the same for trying to repair mine, or should I try and where would I get parts? Can I do it?

    What about the dryer. Again, go to a junk yard and pull any one with right the fittings from the R-12 age? Or, would mine be OK? Buy new one from YO?

    Maybe post in this forum in the WTB section for both?

    Thanks in advance.
  2. mrolds69

    mrolds69 "The Cure"

    You have many questions here! I am licensed for AC work, but I'm really not an expert. It's kind of late to figure out why your old system failed at this point. You did know that changing to R134A, you should have changed the O-rings right? If the compressor is toast, I would buy a rebuilt compressor. You will need a new dryer, that's what absorbs the moisture from the system. You will need to change all the O-rings, you will need a vacuum pump to pressurize the system when filling. You will need A set of manifold gauges and an AC thermometer. It's a big job. I would gather parts and start with the compressor. Look for a rebuilt A6 compressor WITH a clutch/pulley already on it. This will save you time and aggravation. I'm not sure if anybody sells new compressors anymore, and the last NOS ones I saw went for like 3 times what you can buy a rebuilt one for........and they didn't have the pulley clutch on them. You can get a package or assortment O-rings. Maybe put the compressor on W/O belt and just bring it someplace. It's a big job, the tools are expensive!
  3. Stampy

    Stampy Well-Known Member

    The A6 compressor was used on sooo many cars. They are at any parts store... and personally I would put a lot more faith in a rebuilt unit than one that has been sitting at the yard. The case will be pretty much the look you are going for... and then you can buy decals from TA or OPGI for your specific year, so it will look 100% correct.
  4. Stampy

    Stampy Well-Known Member

    Definitely need a new drier though. Nobody will honor warranties on compressors if you don't install a new drier... which says a lot to me about what happens to your new compressor if you don't change out the drier.
  5. SteeveeDee

    SteeveeDee Orange Acres

    If you put TC134A into an R-12 system without changing the oil, that alone can ruin it. The refrigerants require different oils. If you flushed the system components with acetone, make sure to clean it all out before you add oil or refrigerant. Don't use compressed air to blow it out, you will end up with water in the system if you don't have a REALLY good dehydration system on your air compressor. Your best bet is to find a shop with a vacuum pump. Be sure to tell them that you used acetone. AC machines are really expensive now. Mine was $1200 new, back in the '70s. If you ruin someone's machine, they're going to be a bit peeved.

    As has been mentioned, you will need a new receiver dryer compatible with your refrigerant of choice...and the media are different, so be sure of what you ask for, R-12 or TC134A.

    Don't even THINK about a used receiver dryer. It will be junk.

    Also, last I checked, R-12 was $40 a pound. Probably more now, but you can't beat it for cooling power. And you'll need almost 4 pounds.
  6. Briz

    Briz Platinum Level Contributor

  7. djonesutah

    djonesutah Well-Known Member

    Thanks guys. I wish I hadn't aken the easy and wrong route last year. With this help I'll get it. Yep R-12 is expensive. And the new compressor and dryer will be lots. Not a cheap hobby is it? Yesterday I spent over 2 grand getting my snowmobile fixed! Hi HO Hi Ho it's off to work I go.
  8. ceas350

    ceas350 "THE BURNER"

    You need an electric vaccum pump. You can get one from harbor freight for like $50. New compressor and accumilator. You really should use the ac flush stuff pepboys sells it only like $10. You can use compressed air and not have to worry about water in the system, because the vac pump will remove it from the system:) ac gauges are a must. Freeze 12 is a good substitute if one cannot find r12. And buy some automotive ac mineral oil. I like to use the oil the compressor was originally designed to work with. Last time I checked freez 12 was like $12 a can:)
  9. Briz

    Briz Platinum Level Contributor

    I believe you still need an EPA Cert to buy Freeze 12 ( R-414A)
  10. ceas350

    ceas350 "THE BURNER"

    May be true, but last time I went back home to charleston, SC I found it at parts auto parts over the counter with no epa. :)
  11. djonesutah

    djonesutah Well-Known Member

    Bought 12 lbs r12 second hand today for $100. Looks like oldairproducts will have a compressor for around $200 and a dryer for $29ish. Need to call to order to make sure I get the right ones. Will get gauges, vacuum pump, dryer, oil, and flush as been suggested.
  12. ceas350

    ceas350 "THE BURNER"

    Man your on a roll:)
  13. ceas350

    ceas350 "THE BURNER"

    make sure the compressor has the port for the superheat switch if you plan to stay all original. Otherwise it may have a high low port on the back. My suggestion put maybe 50 psi in the system before yo vac it down and let it sit for a while to check for any leaks. Nothin like going through all the work and it all leak out. Ask me how I know
  14. djonesutah

    djonesutah Well-Known Member

    What is a superheat switch?
  15. ceas350

    ceas350 "THE BURNER"

    Attached Files:

  16. lsrx101

    lsrx101 Well-Known Member

    Boy, ain't that the truth!:Dou: That's the big ?? when it comes to an AC system, especially now that any refrigerants are pricy.
    You didn't say what you would use to put 50psi in the system for leak testing.
    -Compressed air is a big No-no (way too wet), and you have no good way to actually find the leaks with it anyway.
    - Dye and a black light works really well, but is only useful after the system is charged and leaks out to some extent.
    - Dry nitrogen and a bit of refrigerant, along with a good ($$$) leak detector and/or a soap bubble mixture is a big part of the "preferred" method before charging. Not everybody has access to comp. nitrogen and an expensive sniffer, though.

    Here's my .02, for what it's worth. Not exactly EPA friendly, but just fine for DIY. I now have charging and recovery equipment for R12, R134a and R22 along with a nitrogen source, so pressurizing and emptying a system is easy for me. I was and still am a DIYer for much more of my life before that, though. It works regardless of the refrigerant that you finally charge the system with.

    -A 12oz can of R134a can be used to pressurize the system.
    -Everybody has quick access to a really good, cheap soap bubble mixture ideal for leak testing AC systems. I would bet money that kids bubbles from Toys R' Us by the quart is nearly the same as commercially available "liquid AC leak detectors". I've used both and can tell very little difference.
    -Auto Zone stores in my area will rent a "pretty decent" refrigerant sniffer for a refundable deposit.

    1. Pull a vacuum on the system. It doesn't need to be a "hard vacuum" . Just get most of the air out.
    2. Pressurize the system with R134a. DON"T RUN THE SYSTEM if you will be using anything other than R134a. (Even if you're using R134a, there's no need to run the system). The equalization pressure between the can and the system is roughly equivalent to the ambient temp. (at 80 degrees, the can and system will equalize at about 80psi).
    3. VERY SLOWLY go over the system with the sniffer at all of the connections, hose crimps and anywhere else you can get the wand on the sniffer. Small leaks will show up as a slight change in the volume or frequency of the "beeps". Did I mention "GO VERY SLOW"? Look for variations in the rhythmic "beep, beep, beep" of the sniffer.
    Large leaks will cause the sniffer to freak out. Tiny leaks cause very small changes in the pattern.

    4. Once you do that and can't detect any leaks, hose the entire system down with soap solution from TR'U. A spray bottle set to "Stream" works ok, but get close and don't squeeze the trigger hard. If you "spritz" it on, you'll get all kinds of bubbles right from the start. On easily accessable joints, crimps, etc. just dribble it on. Keep everything "wet" with the solution and watch for small bubbles piling up.

    5, Once you find the leaks, or lack there of, recover (cough, cough..vent...) that few ounces of refrigerant. Pull a good, hard vacuum and charge with the refrigerant of your choice.

    I'm pretty sure the Superheat Switch only came about in 1970-72 to protect it from being run low on refrigerant. The "high/low" switch followed later, IIRC"
    Prior to 1970 I don't think there was any "protection" for the compressor. The A6 didn't really need "protection" because it had an internal sump full of oil. It could run all day long with no load.
    I cant say for certain, but I think that the superheat switch and later devices were more politically motivated than mechanically motivated,.
  17. ceas350

    ceas350 "THE BURNER"

    Reason I bring up the pressure switch is because its possible to get a compressor with the port on the back for one. We all know the vendors we have out there are not always the most accurate. The superheat and pressure switch ports are two diff sizes, so that does matter when you go to put your switch in your new compressor. When you have a leak not only does the refrigerant leak out but oil does too. Thus the reason for some sort of shut off protection. Ask me how I know... the compressor uses both refrigerant and oil when it operates. Oil to lubricate and refrigerant to keep cool while the clutch is engaged. So let's say you have a leak. First the freon goes to low to even cool off the compressor, at the same time oil leaks out. You end up either messing up the internal rotating assembley or the front seal if you continue to run the ac like most do because they don't know what's really going on. Too much pressure will cause the compressor to lock up or what everyone knows as my compressor clutch locked up:( BTW I'm not tryin to turn this into a big debate on who is right...
  18. lsrx101

    lsrx101 Well-Known Member

    Absolutely not, sir. I couldn't disagree with any of what you wrote. I was mainly just pointing out that the 65 didn't have the switch. I sure didn't intend to sound confrontational.
  19. ceas350

    ceas350 "THE BURNER"

    Cool deal:)

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