Air Conditioning Advice

Discussion in 'Tips 'n' Tricks Topic' started by bcc7771, Oct 26, 2016.

  1. bcc7771

    bcc7771 Veteran Member Lifetime Gold Member

    104
    3
    Oct 10, 2013
    houma,la
    Have a 1978Z and it has all the original AC parts/equipment. Has been sitting for sometime and pretty much assume it does not cool down. Is there anything I can do before bringing it to a AC shop. Shop says could get quite expensive to convert over. I know they sell some type of convert kit for some cars. is there one for ours? Really would like to try something first before dropping allot of money on AC. Any suggestions?
     
  2. harbone66

    harbone66 Veteran Member Lifetime Gold Member

    2,909
    42
    Feb 15, 2011
    Central Illinois
    Do you know for sure the compressor was working before? Conversion is a lot easier than you think and you can get kits about everywhere. Evac the system, remove all the ac lines, receiver drier and compressor. Flush the evaporator and condensor with ac flush along with the ac lines. Drain as much oil as possible out of the compresssor by setting up on its end. Install all new o rings thru the whole system, add the appropriate pag oil in the compressor, get a new receiver drier. Install all new parts and vacuum down for a couple of hours. Recharge system.
    I have done this on my last 2 cars but had to replace the compressors. Total investment in a compressor, rec/drier, orings and pag oil was just a bit over $500 and both the systems worked great when finished. The compressor was the most expensive part, runnng about $375 with a clutch.
     
  3. ssupercoolss

    ssupercoolss Member

    78
    0
    Nov 3, 2015
    PA
    does anything exciting happen when you turn on the AC? like specifically does the compressor turn on? If yes, then it may be worthwhile to just have someone top it off with R12. I havent seen what that stuff has been going for lately, but its not cheap.

    If the compressor doesnt spin, push in on one of the shrader valves just enough to see if there is pressure in the system at all. If there is pressure there, again, maybe just top it off with R12.

    If there is no pressure, without putting a vacuum on the system, you cant add any refrigerant. or, at least you shouldn't. it wont work well if you do.

    Putting some off the shelf refrigerant, the kind with a little hose attached from the big auto parts store is ill advised. it may actually make it cool, but probably not for long, and now you have some type of mixed refrigerent/oil cocktail sludge that no one wants to deal with.

    The advice above is probably the way to go, although if i had to do this all over again, i would really look at replacing the compressor, and i would replace the condenser. R12 condensers are tube fin, R134 condensers are parallel flow. i recently figured out that who ever put my hacked up AC system together, didnt bother to change the condensor. Changing out my condenser was a big improvement with a noticeable temp drop at the vents.

    unfortunately AC = $$, unless you have access to a machine, or have a buddy who has one.
     
  4. NeoNeuro

    NeoNeuro Member

    94
    0
    Aug 4, 2014
    Panama City, FL
    I also have a 78Z and my AC was in much the same situation as yours. It had sit for over 10 years and didn't have an ounce of refrigerant left in it. I did some research on what it was going to cost to get it working again. It wasn't pretty. I also had issues with the vacuum controls and found that rodents had dined on my underhood wiring, pretty much eating the entire AC harness. Since I live in FL doing without AC really isn't an option. I realized it was going to be cheaper and a whole, WHOLE lot less grief to just replace the whole thing with a Vintage Air system. As ssupercoolss said, AC = $$, but now I have an entirely new and more modern system that I don't have to worry about. Unless you have a buddy that can fix the original system on the cheap (relatively), I'd recommend saving up for some Vintage Air goodness. There are several install threads that will help you out if you decide to go that route.
     
  5. bcc7771

    bcc7771 Veteran Member Lifetime Gold Member

    104
    3
    Oct 10, 2013
    houma,la
    need another question answered....I have searched and talked to a few people on this. I have pulled comp. and drained oil. installed new dryer and flushed everything else out with AC flush. got a can of ester oil and my question is...do you put all in comp. or half in comp. and half in dryer? and it appears it takes 8oz?
     
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  6. ssupercoolss

    ssupercoolss Member

    78
    0
    Nov 3, 2015
    PA
    split it up. 8 oz seems a little high to me. too much oil will impact performance, but i always did go on the high side if i was unsure. put some oil in the compressor, and rotate the clutch slowly to lube things up a little. be careful not to spin it too fast or you could burp it back out.
     
  7. 70 Proof

    70 Proof Veteran Member

    165
    1
    Sep 28, 2014
    Southern Utah
    If you decide to try using your original R12 AC system you can purchase 14oz cans of freon for approx $30 (and up) on Ebay or a number of suppliers on the internet. Avoid R12 substitutes that contain propane.
     
  8. bcc7771

    bcc7771 Veteran Member Lifetime Gold Member

    104
    3
    Oct 10, 2013
    houma,la
    swapping over to 134A. going to give that a try and see what happens.
     
  9. bcc7771

    bcc7771 Veteran Member Lifetime Gold Member

    104
    3
    Oct 10, 2013
    houma,la
    Found this on another site. it is from AC Delco.


    1. These components require oil addition prior to assembly:

    Evaporator core - add 1.5 oz.
    Condenser core - add 1 oz.
    Hose/Muffler assembly - 1 oz.
    Accumulator - Drain & measure oil from removed accumulator: then add same amount plus 2 oz. of new refrigerant oil to new accumulator
    Receiver/Dryer - Drain & measure oil from removed receiver/dryer then add same amount plus 1 oz. of new refrigerant oil to new receiver/dryer

    2. If System/Component Flushed - refill system to its total capacity. If one component(s) flushed, add oil amount equal to replacement amount detailed in item#1 above.
     
  10. twozs

    twozs Veteran Member

    7,941
    11
    Aug 5, 1999
    hopewell jct ny
    I can't understand why you would want oil in any part of the system but the compressor ?? The compressor is the only component with moving parts that need to be lubricated . The refrigerant gets impregnated with oil as it runs . If the oil migrates to different components, it can impede their performance. Use oil on threaded fitting when assembling, but other than that ...
     
    Last edited: Nov 12, 2016

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