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Thread: Kral Puncher Hammer / valve failure

  1. #1
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    Default Kral Puncher Hammer / valve failure

    HI all.

    I need some assistance with fixing my Kral.

    Was shooting perfectly and then just the next shot, nothing, it just clicked, but no pressure release from the valve...

    upon disassembly, I found this little shaft in there falling about, and on further googling it seems like that is the tip of the valve, that gets struck by the hammer in order to release the puff into the barrel.
    It also looks like from the couple of trigger pulls I did after the fail, it caused quite a bit of damage to the surroundings in there...

    My question how do one release the pressure in the tube, in order to disassemble the unit, So I can re-fabricate the valve.

    any help would be much appreciated..









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  2. #2
    REP: Outdoor Pitstop
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    On the cylinder it has like a brass(on the one i seen) grub screw. Its called a burst disc or safety valve. Loosen it ever so slightly. You will hear the air escaping. Similar to a bleeder on your fill station
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  3. #3
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    Ah... thanks a lot, yes that did the trick...

    have it all apart now... is was the pin that seem to screw into the valve's plunger that completely disintegrated. Snapped in two places...





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  4. #4
    REP: Outdoor Pitstop
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    Quote Originally Posted by 3Rotor View Post
    Ah... thanks a lot, yes that did the trick...

    have it all apart now... is was the pin that seem to screw into the valve's plunger that completely disintegrated. Snapped in two places...






    Dry firing is 1 contributor to that. Or as others mentioned before, its not hardened steel.
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  5. #5
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    Possible yes, Though I can't say that I have miss-treated it in such a way, If I had to hesitate a guess probably about 10 to 15 dry shots since I got it, 7 months ago.

    lets hope the little pin is not too expensive, else I will have to look at re-fabricating it, that M4 thread is the only bit of a problem as I don't have a die-nut in that size...
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  6. #6
    REP: Xhariep Jagters Colesberg

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    M4 will be in your standard Midas sets, the cheap ones.... Only need to cut the thread once or twice....
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  7. #7
    Sharp Shooter
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    the valve stems are too brittle...seems to be a common issue...tempering them fixes the problem...
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  8. #8
    Sharp Shooter

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    Or you can just use EN19. It's a tough steel, not brittle either and does not need hardening. It will probably outlast the barrel!!!
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  9. #9
    REP: VariTurn Air Rifle Inc.
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    Cost of that valve is R280 Inc VAT. As Dallas says; they are too brittle. Mine snapped at the o-ring. I have since had others made from hardened steel for the pin.
    Watch out for the cocking lever. Similar problem as it is made out of cast aluminium.
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  10. #10
    Protea Benchrest (Air) Team '13/'15/'17

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    Quote Originally Posted by madness View Post
    Or you can just use EN19. It's a tough steel, not brittle either and does not need hardening. It will probably outlast the barrel!!!
    EN19 needs heat treatment, EN19T does not.
    Regardless, heat treatment is easy, heat till it glows red, swirl it in either used motor oil or a very strong sugar water mixture.
    The smoke/gas from the burning motor oil is very poisonous, sugar water on the other hand just makes you crave candy floss.
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  11. #11
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    Thanks Every one, for all the help.. I opted for the re-fabrication... and is busy refilling the tube now... with a hand-pump... damn that's hard work...

    was able to get a piece of 403 Stainless, that I used for the pin, I did not include the o-ring in that though, as that was the weak-spot in the original one, just made sure the tolerance between it and the housing is nice and tight.

    the other weak-spot was the thread, so there I opted to fabricate a new plunger and went for a press-fit between it and the pin.

    will be testing it out as soon as I get it all filled up again...



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  12. #12
    Cadet

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    Hi 3Rotor!

    I had the same problem with my main valve! The little grub screw on the hammer has taken a beating as well...the thread has been damaged and now it falls out. The Breaker seems to function 100% without the grub screw though... Would you recommend getting the hammer threaded and new screw fitted?

    Regards,

    Matthys
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