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  1. #1
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    Sep 2008
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    Odd fuction of BluVac +Pro

    First, I do like this micron gauge. However, I find it to be suspect at times.

    Lately, when I pull a vacuum, it frequently gets stuck at 1300-1800 microns. Then I will repressurize system up to atmosheric with nitrogen, and it will immediately pull down to ~150 or so, and hold steady. Logic would tell me it's moisture, but I'm not so sure because it's been happing more frequently.

    Just yesterday I was pulling a vacuum on a brand new lineset and the reading went down to ~140ish, then I go out to check and it's now reading over 1500 and rising??? So, I repressurize the system to atmospheric, and reevacuate. The reading shoots down quickly and ends up below 100 microns. I valve off my Appion VCRT's and it holds for several minutes not rising above 150. So, I don't think it's the valve core tools.

    There has been occassions where I remove the BluVac only and lightly blow into the end to raise the reading to atmospheric, reconnect and find it drops past the sticking point of 1300-1800 microns.

    Anyone else have this issue?
    "The only true wisdom is in knowing you know nothing" Socrates

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  2. #2
    Join Date
    Dec 2007
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    I have had similar issues and have been blaming the vcrt or schrader.

    Have you tried a vacuum without cores in the vcrt and gauge?
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  3. #3
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    Thread Starter
    Quote Originally Posted by pacnw View Post

    Have you tried a vacuum without cores in the vcrt and gauge?
    I'm assuming you're talking about the core in the side port of the vcrt, and the core depressor of the BluVac extension?
    No, I haven't tried removing the core and depressor. Have you had any success with that?
    "The only true wisdom is in knowing you know nothing" Socrates

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  4. #4
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    Aug 2015
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    Sounds like you need to adjust the depressor in the blue vac extension or possibly the o ring in it. Been down that road a few times.


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  5. #5
    Join Date
    Nov 2011
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    you could also have air trapped in the ball of the appions. I always cycle the ball valve several times after I get down below 1000 microns. very frequently the valve has trapped air or nitrogen in them. appion has mentioned this in posts several times over the years.


    also, you could have bad hose seals, when you pull them off and reconnect, you could be sealing where they weren't before. if I see pulling down and jumping back quickly around that range, I always suspect a leak.


    are you using a vacuum tree, or pulling through your gauges?


    also, you should be checking your vacuum rig BEFORE the valve core tools every vacuum. if your pump and hoses can't pull below 500 BEFORE the core tools, it will never pull the system down AFTER the core tools. I always put the micron gauge on top of the tree, leave the core tools closed, do the test, then open to the system and start evacuation.

  6. #6
    Join Date
    Dec 2004
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    The other thing to watch out for is a small pocket of refrigerant. If you recover, or release the charge or add charge with the core tool connected, like I do, over time the o-ring of the core in the side port can absorb refrigerant and its oil, and refrigerant will give a false low reading, but not super low.

    1000 to 1500 territory is the false micron level that I have experienced. Try replacing the side port core, or removing altogether.

  7. #7
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    Sep 2008
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    Thread Starter
    I've tried removing the vcrt's side port schrader on the last mini-split install. New 1/4" & 3/8" lineset, one hose pull down. It pulled down to 65.6 microns and only rose to 110.7 after ~4 minutes in decay.
    The initial drop and curve seemed much more linear, much less ripple in the graphic display.
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