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Flushing AC lines

Discussion in 'Technical Discussion' started by Beau, Aug 17, 2019.

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  1. Beau

    Beau Senior Member

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    So I suspect this is a question that is not the brightest , but can I flush my A/C units after the racor, but before for the magnetic pumps, or do I need to gets to the out bound hose??
  2. Capt Ralph

    Capt Ralph Senior Member

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    A/C lines do not go thru the fuel filters...
    Try this again..
  3. Pascal

    Pascal Senior Member

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    Rabies?? Or do you mean strainer?

    The easiest way to descale is usually by disconnecting the hose on the outlet of the pump and returning the cleaning mix from the discharge hoses. This way you get the whole system incl the discharge lines.

    But it also depends on the layout of the system.

    I m not a fan of using the cleaning mix in the pump
  4. Capt J

    Capt J Senior Member

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    I'm not a fan of circulating the cleaning mix through the pump either.

    But I've seen some A/C outfits circulate the TRAC stuff through the strainer, pump, and everything for 8+ hours.
  5. Beau

    Beau Senior Member

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    Duh! Groco…. Is Barnacle Buster any good?
  6. bayoubud

    bayoubud Senior Member

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    What is safe? Our chiller mfg says Trac Barnacle Buster and 1" chlorine tablets will corrode cupronickel tubing.
  7. Capt J

    Capt J Senior Member

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    I use Bromine tablets, NOT chlorine tablets.

    Before Trac, lots of techs descaled chillers with muriatic acid which is way harsh. Trac claims that it is safe to use and is what I see a lot of A/C techs using nowadays. The Dometic chillers now have titanium sea water coils to fight erosion. But what else are you going to clean them with?
  8. Pascal

    Pascal Senior Member

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    BB is supposed to be less corrosive than muriatic acid

    I guess it should be ok in March pumps since there is only one o ring on the cover. I would not use it with metal impeller pumps
  9. bayoubud

    bayoubud Senior Member

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    I meant bromide tablets, most techs use Trac and they claim the same as Rydlyme. I don't know what else to use that would do the job and claim to not harm the metal.
  10. bayoubud

    bayoubud Senior Member

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    Says BB uses phosphoric acid which is fairly mild. Never ran BB though a pump, but why not use it on metal impellers?
  11. Pascal

    Pascal Senior Member

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    Metal impellers like in Cruisair branded pumps or Scott pumps are pretty thin and eventually corrode and erode away. I d be reluctant to expose them to any chemical
  12. Capt J

    Capt J Senior Member

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    I'm not so worried about the impellors as much as I am worried about the rubber or nitrile pump seals.
  13. Capt Ralph

    Capt Ralph Senior Member

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    The reason we spec nitrile is; it is chemical resistant.
    Last edited: Aug 18, 2019
  14. Capt Ralph

    Capt Ralph Senior Member

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    I purchase BB concentrate. Works for most of my needs. It's still greatly reduced and will not fry your hands (much) of kill the copper.


    When I really need a molten pile of couperious copper, I get the muriatic acid.
    Also called Hydrochloric acid.
    Last edited: Aug 18, 2019
  15. ranger42c

    ranger42c Senior member

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    FWIW, I've used both Rydlyme and Barnacle Buster. Both worked well, no visible sign of related corrosion. (Although if there has been some ill effect, it likely wouldn't be visible -- to me -- anyway.)

    I injected solution starting at a flush valve (just after the thru-hull), through the sea strainer, through the AC pump, through the ACs... and then overboard via the AC raw water discharge thru-hulls. Since it wasn't easy to capture and recirculate, I injected until the system was full, let it rest awhile, injected some more (flushing the previous load), repeated that a few times. Works better if the sea strainer is cleaned first and the circulation system has already been flushed with fresh water.

    -Chris
  16. CSkipR

    CSkipR Member

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  17. bayoubud

    bayoubud Senior Member

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    About 6 years ago while at Stuart, Fl bought a product from a locally, "Triton Marine engine descaler." Think they went out of business, sounds like the same product. Used it on my 3412's, cleaned the HE's while there at the dock. The tech said no acid and you could leave in place for a couple of days without metal damage. Thanks for the post, if no acid it will be my choice.
  18. Capt Ralph

    Capt Ralph Senior Member

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    The best thing, the 34XX HEs were rock solid and IMO; oversized, not penny pinched.
    Any air cooler and HE that Cat has put together since has had problems bringing their latest service statement; replacing Air Coolers per calendar time vs hours. IMO, this is BS.
  19. bayoubud

    bayoubud Senior Member

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    Ralph, our 3412's were great engines. The HE's had a lot of capacity, never had a temp issue. I'm with you on the aftercooler replacement change. They did not do their customers any favors cleaning every 2 years and replacing every 6 years, no hours mentioned. I was told they made the change because of extended warranty claims. Bought a pair for our 3406's last summer, but they needed replacing, the PO had neglected them for years. Oops, got off subject.
  20. Capt J

    Capt J Senior Member

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    I had to undergo a warranty rebuild on a 2-3 year old C32 because the aftercooler leaked. I know several 2008 +/- 1 year C18's that had to have a major because an aftercooler leaked. It is a known issue and a problem.

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