Seneca Dragonfly (or her sister) : need some help

[Ultramarine]

Ped,

As you may have guessed reading me, I'm sometimes fighting for an acceptable english, but I also miss a big part of technical vocabulary, though being a GTA fan, not only member.

So, refering to the Seneca Dragonfly exploded view above mentionned, could you tell me what's the "stem" and its seal ? Is it what they call "exhaust valve pin". If so, as soon as I have time, I'll try Tkerrigan's trick, as the exhaust valve core (it's how they call it) doesn't seem to have any seal.

Regards,
Yves

[ped]

part no 46 Yves the white Teflon taper is what seals in the valve and will be the part that is leaking

[Ultramarine]

Thanks Ped, I had guessed it right (phew!) and I tried the solution Tom suggested.
It took me some time.  Not the solution, but disassembling and reassembling. And two "nicked" screws now, one on the pump axis cover cap and the other one  in the small metal piece which helps to place the shoulder stock properly...
Well, my first test drove me quite optimistic : pumping was normally hard and I could hear no "hiss" when dry firing. Then I pumped  6 times and let the rifle for half and hour. Alas, poor Yago Yves, the only sound I could here, once again, was the hammer hitting the valve!
May be I just didn't polish that teflon taper enough. Or could it be the other taper, the one of the intake valve?   I'll do that later on.
Regards,
Yves

[xtred1]

Your drawing was very good! I kept it as one day I might need it.

[Ultramarine]

Thanks Paulus but you'd better refer to the pic I attached to the post I sent on December 2nd, 'cause I didn't locate the exhaust port properly. I attach it to this post again.
BTW, I'm going to put that rifle in a locker for a while : tried to shoot this morning, it hissed like an angry snake and wouldn't keep pressure . I'm fed up, and I'm not going to spend more hours looking for what causes that *?%>>**^!lof a leaking.

[TerryM]

  The first air gun I ever worked on was a Crosman 180.  A CO2 gun, but the same type valve as a pneumatic.  Soon after my reseal job, it began to leak.  After disassembling again, I closely examined the seating surface of the valve stem and found a tiny crumb of metal stuck in it.  This is a hard delrin or nylon type plastic.  The offending bit was invisible without magnification.  After I picked it out, there was a tiny pit where it had been pressed into the plastic.  Chucked the stem in a drill and carefully spun the seat against fine sandpaper till it was smooth again.  The gun has been fine ever since, it is one of my favorite shooters.

[Ultramarine]

Thanks Terry,

I'll keep this in mind until I unburry this Snow Peak rifle from its locker. Your advice is close to Tom's one and I can be but heedful to it.
But where's the hissing sound coming from ? Could it be the improperly cured intake poppet ? Or a big leak  at the exhaust port  ? Though the valve unit position looks perfect, "35 Shooter's" observation about it troubled me.
I have to admit I'm going to let things rest till I can read an actual intervention report on this valve unit. Don't wan't (for the moment) wrap the rifle on a tree trunk, according to the consecrated formula (I wouldn't be able to do that, anyway. Still expecting a video showing such a performance ).

Regards,
Yves

[Relentless Holiday]

Yves, Sorry to learn of this struggle.  Thankfully I have not needed to address any valve issues, so I can't help.  Just letting you know I feel your frustration. Hope it comes together for you when you go in again.  I'll probably need help on it someday also.

[Ultramarine]

Should have mentionned that these last days the intake valve stopped leaking and the rifle almost stopped hissing. More important, I went back to a real decent accuracy. I conclude the combined advises of TKerrigan and TerryM brought this rifle back to life. Thanks a big bunch !
Now the bolt is still jumping at every shot which, if I'm not wrong, means that I should check the bolt seal. b*ù&#ùt!!! I'll wait till next year to play with this.