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Oil Residue in Manifold Set

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  • Oil Residue in Manifold Set


    Anybody know of a good method / solvent for thoroughly cleaning out a manifold gauge set and charging hoses?

    I ask this because I recently used my old Yellow Jacket manifold gauge set to top off my wife's car with R-134a. As is typical, when I disconnected the high-side hose, I got a nice little spray of PAG oil. I didn't think much of this until I realized that this is the same manifold set that I use for periodic maintenance on my central air system with R-22/mineral oil. I definitely don't want to end up cross-contaminating my home air conditioner with residual PAG oil from my hoses.

    Last edited by RJSalucci; 06-12-2023, 05:35 PM.

  • #2
    Welcome - Sorry I'm so late to see this very valid question. It spurs another such as does this set self seal hose ends or just open all the time? I've dealt with now 3 sets one failed kept for hoses and parts.

    OK, I'd blow lots of shop air thru If locking/blocked ends use blank retrofit adaptors and have unions and connectors for R-12, R-22 most the same threads and have at them with air every which way.

    AYOR if you use a flush I'd hold off as last if hoses and guts to manifold reacted or were destroyed by one kind or another?

    You can replace hose end seals are not an "O" ring rather a longer tube appears differently until out with dental picks!

    Unique to your use of course don't mix up gases or oils I do all but 1234yf not going there.

    Gauges always put it state of vacuum left that way and redone for each use.

    I'm with you for the assorted use 95% done/retired from it was portable as I could be to be able if only diagnose homes, cars, vehicles and a decade of yachts that used R-22 and service ports. So does my current home A/C untouched for years now replaced caps with brass ages ago too - plain caps, ports of any frequently the fault of low charges!

    Good luck. Think it out and think hardware stores if handy for you web shopping for some stuff has really failed me just wrong packaging or cloned junk is disappointing too much,

    MetroWest, Boston


    • RJSalucci
      RJSalucci commented
      Editing a comment
      Thanks for the reply Tom. That’s a lot of good information. And to answer your question; no, mine are not the self-sealing hoses. They can flow all the time. I usually connect them to the dummy ports on the front of the manifold when not in use though so that they aren’t open to the atmosphere to collect dust and other airborne junk.
      Last edited by RJSalucci; 06-14-2023, 12:09 PM.

  • #3
    You should be good then. The EPA ends I don't care for at all. I like to bleed out line(s) if hooked up to refrigerant just a spit and quick attach every particle of plain air is ruining characteristics of refrigerant.
    IDK how old now still have 1st set "Robinaire"= Snap-On are tops but lasted still. Just those tube "O" rings in ends. Once if not now adaptor ends from old threads to Acme have turn ball valves. I understand them moves shut off knobs to the ball valves knobs to read pressures and allow refrigerant to pass through. Know your own stuff it's not all the same,
    MetroWest, Boston