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  1. #1
    Join Date
    Mar 2002
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    Concord, CA
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    2,635

    Question Quickest way to extract *some* oil from a compressor that's not being replaced?

    My thought is to cut the suction line and use an automotive style extractor.

    Thoughts on that idea? Better ideas?

    I think it might work well on a recip. I'm not as certain about scrolls.

  2. #2
    Join Date
    Mar 2009
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    Mid-Mo
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    3,596
    Why are you thinking you need to get an oil sample?

  3. #3
    Join Date
    Mar 2002
    Location
    Concord, CA
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    2,635
    It's not to sample. It's to convert to from R-22 to R-407C.

    I don't know if this is widely accepted, but it's what I'm going with: The gentleman that put this class on states that we need only a 20% POE charge to get adequate oil return in a typical (non-lengthy non-crazy piping) high temp application. (That specific point isn't in the slide show.) The many experienced medium and low temp dudes in attendance did not object. One manufacturer's experiments showed 10% as being sufficient. 20% will be my minimum, generally more.

    That being the case, there's no need to cut both lines and tip the compressor to get all the mineral oil out. When possible I'll leave the compressor in place, cut the suction line only and suck some oil out before putting the POE in.

    I just wanted to know if anyone has done that or something else. I don't know how easily a plastic tube will fit down inside and if it will catch on something. I may have to yank the compressor.

  4. #4
    Join Date
    Aug 2012
    Posts
    2,675
    It sounds as though r407c is the way to go on residential retrofits would you concur??
    As far as your tube idea I guess it wouldn't hurt to try.
    My name is TooCoolforschool and I am a chronic over charger.

  5. #5
    Join Date
    Mar 2002
    Location
    Concord, CA
    Posts
    2,635
    I've performed a lot of searches on this forum and on the net in general. It appears that, for high temp at least, R-438A is the best no oil change choice and R-407C is the best "some oil change choice".

  6. #6
    Join Date
    Apr 2012
    Location
    Louisiana
    Posts
    715
    Cut out the compressor turn upside down and measure drained oil. Replace measured amount with Poe and sweat compressor back in.
    Just don't quote me on it.
    : )

  7. #7
    Join Date
    Mar 2002
    Location
    Concord, CA
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    2,635
    Thank you Sic! The point of this thread is to, if possible, avoid compressor removal. Maybe it's a crazy thought, but I won't know till I try.

  8. #8
    Join Date
    Sep 2003
    Location
    Western PA
    Posts
    1,359
    A great old timer once showed me how to "burp" and evaporator to remove oil. Maybe it would would on a compressor?
    Local 449?

  9. #9
    Join Date
    Apr 2012
    Location
    Louisiana
    Posts
    715
    Quote Originally Posted by Irascible View Post
    Thank you Sic! The point of this thread is to, if possible, avoid compressor removal. Maybe it's a crazy thought, but I won't know till I try.
    I have and use a small engine oil remover like the ones linked to do oil changes on 12.5 ton and larger scrolls in tandem setups that do not have an oil drain. But I have only ever used the oil equalization/site glass port. I'm just not sure if pulling out the suction will allow access to most of the oil.

  10. #10
    Join Date
    Feb 2009
    Location
    Tallahassee, FL
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    6,051
    If you are cutting the suction line anyway how much harder would it be to just remove it? not much.

  11. #11
    Join Date
    May 2010
    Location
    Oxford, UK
    Posts
    338
    I have done this once on a L'unite/Tecumseh R22 comp, it was a rotalock model so no pipe to feed tube along. You will need something super flexible, i used silicone fuel tube for radio controlled cars.
    The compressor was a replacement for a failed model that had pumped its oil out on failure, it was in a roof space with limited room to remove it and tip it up which would have been a better option. (ended up taking out three times the correct oil)

    Personally if there is room i would remove the compressor and carefully measure out all the oil and replace with poe. Mixes of different oils can go frothy and lead to lubrication failures, depends on what additives etc there is in the oil. Not worth the risk imho.
    When i did a lot of work with Castrol when they were developing their Icematic poe oils they recommended the residual mineral content be below 3% which generally took 3 to 4 complete changes and some run time.

    You will not be able to feed a pipe down inside a copeland scroll as the stator is quite tight to the shell. Some of the bigger ones have strainers in the inlet anyway.

  12. #12
    Join Date
    Mar 2002
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    Concord, CA
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    2,635
    Thank you for the feedback gents.

  13. #13
    Join Date
    Sep 2009
    Location
    Kennesaw, GA
    Posts
    584
    Quote Originally Posted by monkeyspanners View Post
    I have done this once on a L'unite/Tecumseh R22 comp, it was a rotalock model so no pipe to feed tube along. You will need something super flexible, i used silicone fuel tube for radio controlled cars.
    The compressor was a replacement for a failed model that had pumped its oil out on failure, it was in a roof space with limited room to remove it and tip it up which would have been a better option. (ended up taking out three times the correct oil)

    Personally if there is room i would remove the compressor and carefully measure out all the oil and replace with poe. Mixes of different oils can go frothy and lead to lubrication failures, depends on what additives etc there is in the oil. Not worth the risk imho.
    When i did a lot of work with Castrol when they were developing their Icematic poe oils they recommended the residual mineral content be below 3% which generally took 3 to 4 complete changes and some run time.

    You will not be able to feed a pipe down inside a copeland scroll as the stator is quite tight to the shell. Some of the bigger ones have strainers in the inlet anyway.
    when you say '3-4 change's , you mean you dumped and refilled 3 times the poe oil? I maybe posting here soon of experiment with r-407c. We plan to pick one unit in class and retrofit 407 on it and see how it performs.
    wHen I diE I hOpe gOd haS mErcy oN my SiNful LifE

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