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Thread: Retro Valve venting out back

  1. #1

    Retro Valve venting out back

    This valve has been working fine for the longest time and just started doing this. It vents at what seems like full pressure out the rear as soon as I turn the air on but if I pull the trigger it stops and works fine until I turn the air off and back on again. I assume that means something isn't quite seating correctly but not sure how to remedy it. Any ideas?

    Thanks!

  2. #2
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    take the back of the valve apart and check the orings and everything for wear, if not you could have a reg thats going

  3. #3
    I did that once and looked everything over and wiped it down and put it back together. It seemed to fix it temporarily but then it started doing it again. Any idea what o-ring I should specifically target?

  4. #4
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    There is a clear diaphragm inside the reg piston. Try opening it up and flipping it.

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    Replace the regulator piston. Email me if you need one.
    Email me for low prices on ALL AGD Products and more. tunaman5@verizon.net
    Tunamart

  6. #6
    Quote Originally Posted by Tunaman View Post
    Replace the regulator piston. Email me if you need one.
    Will do. Is it worth trying to open up the old one first?

  7. #7
    Honestly, no, not for the price of a new one compared to the headaches involved in trying to fix one that has effectively expired.

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    Quote Originally Posted by Justus View Post
    Honestly, no, not for the price of a new one compared to the headaches involved in trying to fix one that has effectively expired.
    Gonna have to disagree. Takes 5 mins to disassemble the reg and pop the piston housing apart and flip the diaphragm vs $30 for a new assembly. If you somehow screw it up you can just buy a new one.

  9. #9
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    Quote Originally Posted by OPBN View Post
    Gonna have to disagree. Takes 5 mins to disassemble the reg and pop the piston housing apart and flip the diaphragm vs $30 for a new assembly. If you somehow screw it up you can just buy a new one.
    Flipping the diaphram will effectively do NOTHING to fix the problem. The problem lies with spring fatigue...not the diaphram. This is also a safety device so messing with it causes liability issues on your part.

  10. #10
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    Quote Originally Posted by Tunaman View Post
    Flipping the diaphram will effectively do NOTHING to fix the problem. The problem lies with spring fatigue...not the diaphram. This is also a safety device so messing with it causes liability issues on your part.
    Ok. It was recommended for me to try this a couple of years back on an X of mine that was leaking like this. Mine was a fairly minor leak though and it fixed it. I don't get the safety issue thing. As long as you put it back together EXACTLY like it came apart, including counting the number of turns on the inner nut, what does it hurt?

  11. #11
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    Quote Originally Posted by OPBN View Post
    Ok. It was recommended for me to try this a couple of years back on an X of mine that was leaking like this. Mine was a fairly minor leak though and it fixed it. I don't get the safety issue thing. As long as you put it back together EXACTLY like it came apart, including counting the number of turns on the inner nut, what does it hurt?
    Unless you have the proper jig and gauge setup for properly adjusting the reg blow off setting you are wasting your time. If you screw it up you risk having it blow up in your face.

  12. #12
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    Tuna? An honest question here. With a more personal answer than businessman outlook preferred. Not trying to be a jerk. It really is an honest curiosity of mine. Especially since I think the one in my automagRT is finally going bad after all these years.

    What could blow up without a hand full of failures? The reg is rated at 3k. And pretty sure full pressure would trash paint. From a businessman standpoint I agree with you. But I was on the understanding that reg piston blow off is a fail safe for fps. And not much more than that. So basically it could be shimmed down and made where it wouldn't leak at all. Ever. And really the only risk would be if there were other failures that cause shooting hot. And explosion would take basically everything failing. And then if the reg is rated at 3k. I'm betting it would withstand 45 if somehow you really had that many things go wrong at once.

  13. #13
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    I go through both ends of this argument in my head whenever it comes up.

    If you don't understand exactly what the relief is doing, just get the new one.

    The mechanical term for the metal condition is "creep", and is the same problem you find in long term loaded firearm magazines. "Fatigue" is associated with cycling, which doesn't happen in this case and can get a lot more complicated when you look it up.

    Besides counting turns, I would make an alignment mark on the nut and piston, since a quarter of a turn is significant. They are mechanical after all, and that exact position should be good for the original set pressure or less.

    While the reg is rated for 3k, body washers have been known to come loose (especially when you leave the bolt spring out). The reg itself has a high probability of seal failure, meaning when something gives, it will probably be there. When the reg seal gives up, you don't want the bolt to beat everything else up. The relief helps that. However, the relief doesn't normally flow. Once it does, it has the chance to take in dirt and oil where it was a clean seal before. A leaky piston relief may just need cleaning, but flipping the seal may help even out the aging.

    Another problem is when you sell a valve. Since mags last through several owners, you can more easily end up with a chain of failures. Case in point is the center feed mag without the twistlock pin. If that mag was using a friction fit barrel and had the reg fail with no relief, we are looking at an older body washer that had plenty of opportunity for abuse. I expect that the bolt, washer and barrel would stop about halfway down the minimag body and continue to vent the bottle. Nothing terribly tragic in that, but the mag gets jacked up.

    Anyway, if you mess with one, be willing to bet your best mag on the results, i.e. take it seriously. You need gauges once you get away from the factory setting.

  14. #14
    Thanks for all the replies everyone. I just wanted to say one other thing about how this valve is behaving and see if you all still this it's the regulator piston that needs replacing.

    The venting only happens if it's the first time I put air through the marker after it's been sitting. If I pull the trigger it stops and then the valve functions perfectly. I can then de-gas the system and air it back up and it does not vent out the rear. I tried this probably 10 times tonight and it worked fine.

    Again, I just wanted to make sure I was clear in the representation of this issue before I ordered a regulator piston from Tuna.

    Thanks.

  15. #15
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    If the valve has never had the piston assembly replaced, it may need to be done anyway. The newer piston assemblies have a higher pressure release than earlier versions, so they work better with level 10 bolts.
    Except for the Automag in front, its usually the man behind the equipment that counts.

  16. #16
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    Quote Originally Posted by robertreed711 View Post
    Thanks for all the replies everyone. I just wanted to say one other thing about how this valve is behaving and see if you all still this it's the regulator piston that needs replacing.

    The venting only happens if it's the first time I put air through the marker after it's been sitting. If I pull the trigger it stops and then the valve functions perfectly. I can then de-gas the system and air it back up and it does not vent out the rear. I tried this probably 10 times tonight and it worked fine.

    Again, I just wanted to make sure I was clear in the representation of this issue before I ordered a regulator piston from Tuna.

    Thanks.

    The piston may be sticking, causing excess pressure that is being vented properly. Have you changed the piston o-ring and cleaned the reg? A sticky piston will show up at the chrono also. The reg pin can be just as guilty though.

  17. #17
    Quote Originally Posted by Spider-TW View Post
    The piston may be sticking, causing excess pressure that is being vented properly. Have you changed the piston o-ring and cleaned the reg? A sticky piston will show up at the chrono also. The reg pin can be just as guilty though.
    How will it show at the chrono? Inconsistency?

  18. #18
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    Quote Originally Posted by robertreed711 View Post
    How will it show at the chrono? Inconsistency?
    Yes

  19. #19
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    Spider. I've sent tuna an email and a pm about getting a new one. And parts kits for my guns. I was just debating on messing with my wore out one once that is confirmed as my actual problem. But with the age. I would assume so.

  20. #20
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    Quote Originally Posted by blackdeath1k View Post
    Spider. I've sent tuna an email and a pm about getting a new one. And parts kits for my guns. I was just debating on messing with my wore out one once that is confirmed as my actual problem. But with the age. I would assume so.
    New parts are always good (well, almost always).

    If you open it up, there's another thing to look for. The seal (urethane?) disc can get dented by the spring (I can't remember if these have a backing washer). If the seal dents from the spring, that relieves the tension of the spring that much, which is worth a quarter of a turn or so on the nut. If you flip the seal over, you eliminate the dent. I may be thinking of the micro ca check valve arrangement, but I think they are similar, with just a spring on top of a urethane disc.

    So there's three things to mess up the piston relief;

    Seal set
    Spring creep
    Dirt and debris

    As long a Tuna and AGD has some in stock, there's not much left on a mag that we can't replace with some work. Eventually, we die-hards will need to know how to build or rebuild these pistons properly instead of leaving them as mystery safety parts.

  21. #21
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    is there anyway to tell the difference visually between the older and newer reg pistons with out taking them apart or swapping the reg pistons to see if it leaks??

    i always just swap a unknown reg piston from a RT type valve that only has a lvl 7 bolt and test it in a different RT type valve with a lvl 10...if i get a leak ill write 7 on it...no leak ill write 10 on it...but sometimes tha writing wears off not to mention i drink alot of beers and just forget sometimes

    they look identical tho which is why im asking? but when it comes to a part that AGD says is a non-user serviceable part or if Tuna recommends not trying to fix on your own its better safe than sorry to get a new one. same with buying a new sear...if i need a new sear ill only buy new or from someone i know or in person.

    its not like the reg pistons go out all the time so spending 30 bucks to make sure your not sitting out of a game trying to trouble shoot your is worth it...and while your at it pick up a few extra o-rings and pay for the shipping all at once?

  22. #22
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    It crossed my mind to just make a solid one from brass on a lathe. But yes. As long as I can buy the correct parts I will. But for now. Parts kits and a piston are on there way. 4 dollars shipping isn't bad at all. And a 25 dollar piston..... can't complain.

    What are we gonna do when the surplus parts dry up?

  23. #23
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    Quote Originally Posted by blackdeath1k View Post
    It crossed my mind to just make a solid one from brass on a lathe. But yes. As long as I can buy the correct parts I will. But for now. Parts kits and a piston are on there way. 4 dollars shipping isn't bad at all. And a 25 dollar piston..... can't complain.

    What are we gonna do when the surplus parts dry up?

    that would be pretty Sa WeeT if you could make your own. do you know the proper settings or have a way to test for those proper settings? thinking that would be the hardest part of making your own?

    when ya gonna try it eh?

    if tha surplus parts dry up that would be a bummer man...hopefully thats not something that will happen any time soon yo?

  24. #24
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    Quote Originally Posted by need4reebs View Post
    that would be pretty Sa WeeT if you could make your own. do you know the proper settings or have a way to test for those proper settings? thinking that would be the hardest part of making your own?

    when ya gonna try it eh?

    if tha surplus parts dry up that would be a bummer man...hopefully thats not something that will happen any time soon yo?
    Sorry if I wasn't totally clear. If I made my own it would just be a solid brass piston with the indention for the needle. And the o ring groove. So no spring. No venting capabilities. There for it would be a personal deal for personal use. Other option with the same outcome would be dismantling a stock piston. And using a solid shim instead of a spring inside. But there again. The relief capability would not be there. And actually the second option is what I may mess with once my gun has the venting issue stopped with factory parts.

  25. #25
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    Quote Originally Posted by Spider-TW View Post

    As long a Tuna and AGD has some in stock, there's not much left on a mag that we can't replace with some work. Eventually, we die-hards will need to know how to build or rebuild these pistons properly instead of leaving them as mystery safety parts.
    Knowing how TK is with everything else. I've got a feeling that the factory specs will come out to the public or something to help salve any problems with this.

  26. #26
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    here is a how-to-video...but even tha dood working on the reg piston says its a temporary fix?
    http://www.youtube.com/watch?v=wfcnqeIznLQ

  27. #27
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    Quote Originally Posted by need4reebs View Post
    here is a how-to-video...but even tha dood working on the reg piston says its a temporary fix?
    http://www.youtube.com/watch?v=wfcnqeIznLQ
    Temp for the next 10 years.

  28. #28
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    Quote Originally Posted by blackdeath1k View Post
    Temp for the next 10 years.
    haha...ya never know man???

    10 years is a long time to even think about eh...day by day is as far as ill look ahead ya kno?

    hope that video helped ya out some tho.

  29. #29
    Does Tuna rebuild these? Assuming that there's a time that all suppliers are out of these, how hard would it be to source the spring and urethane seal to have rebuilds done? I may be playing chicken little here, but you just have to go back a couple years to remember when the very last 4.5k Flatline reg seats were sold off.

  30. #30
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    Just got to watch the vid. That looks more functional than what I'm thinking about. I'm thinking seal it up tight where it might as well be a solid chunk of brass.

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