weird classic leak

[rawbutter]

I'm at my wits end here.

I've already replaced all the o-rings in the valve.

If I put this valve on another automag, it leaks. If I put a different valve on this automag, it's okay. So I know it's the valve.

I also know it's not the on/off. I put a brand new RT on/off in there, and it was still acting weird.

Any ideas?

[rawbutter]

Oh, before I forget, the valve back is one of those weird venturi backs with lots of extra holes, just like the one in this picture. Never had one of these before. Could that be part of the issue?

IMG_20150518_175340.jpg

[going_home]

[blackdeath1k]

This may sound really stupid. And I'm saying his because I ran in to this problem a year or so ago. Check the seals that could cause the leak for pet hair. Or very fine nicks or indentions. Both of these things have kicked my but in the past. Had to dismantle a pops asa due to it leaking in October. It had a cat hair somehow get in it and created a leak past the seal. Same thing with one of my RTs. The nicks or indentions in new seals ive seen off and on over the years. Sadly new does not always mean good.

[athomas]

That sounds like a powertube oring issue. If it didn't leak before you changed that oring, then your powertube spacer is probably ok, so try a different oring there. You can confirm if it is a powertube issue or an on-off issue by holding the trigger in. If it shoots and then sputters when the trigger is held, then the problem is the on-off. If it shoots and then there is no sputtering when you hold the trigger in, then the problem is in the powertube.

[Evil1]

That sounds like a powertube oring issue. If it didn't leak before you changed that oring, then your powertube spacer is probably ok, so try a different oring there. You can confirm if it is a powertube issue or an on-off issue by holding the trigger in. If it shoots and then sputters when the trigger is held, then the problem is the on-off. If it shoots and then there is no sputtering when you hold the trigger in, then the problem is in the powertube.

This is also an issue I had years ago and it was the trigger rod.

[rawbutter]

This may sound really stupid. And I'm saying his because I ran in to this problem a year or so ago. Check the seals that could cause the leak for pet hair. Or very fine nicks or indentions. Both of these things have kicked my but in the past. Had to dismantle a pops asa due to it leaking in October. It had a cat hair somehow get in it and created a leak past the seal. Same thing with one of my RTs. The nicks or indentions in new seals ive seen off and on over the years. Sadly new does not always mean good.

I went through the on/off and changed the o-rings a second time, and that seemed to do the trick. It's working better now.

Although now it's shooting on pull AND release sometimes. I haven't decided yet if that's good or bad.

[ghost flanker]

That's bad. That means the sear is failing to catch the bolt when the on/off valve opens. The culprit could be one of these:

- The RT on/off you're using has a pin that is too short. Switch back to an AM/MM on/off that is known to be good.
- The sear is worn. Replace with one known to be good.
- The bolt is worn. Replace with one known to be good.
- The trigger rod is improperly set. Adjust trigger rod so that it is 1mm from the trigger at full-travel-forward while the gun is pressurized.

[athomas]

Firing on the pull and release is a timing issue where the sear isn't catching the bolt before the on-off is opening. That could be a bolt or sear issue where either might be worn. It could also be an on-off pin length issue. The trigger rod length shouldn't cause that problem. Usually a trigger rod will cause short stroking and charge issues if too long, or won't fire if too short.

Generally, the shoot on pull and release is an on-off related issue due to leaking past the top oring. Try gently firing a shot and holding it. Note if there are any leaks out the front. Then, gently release the trigger. You should hear the bolt click against the sear when the on-off opens. If it doesn't and the gun fires, then the on-off is opening too soon. That would be caused either by the pin being too short, or by the sealing edge of the oring being in the wrong place.

Is your rail bushing in place? Make sure your rear field strip screw is not too long causing it to bottom out in the valve. A washer will fix that.

[rawbutter]

I hate to break it to you guys, but it was none of those things. Good try, though.

When I first got this marker, before even test firing, I was planning to install a Level 10, so I switched the reg piston from the old brass style to the newer stainless steel style, but then I never got around to it because I ran into all the other problems. I remembered this fact this afternoon and went to switch the reg piston back, only to discover that the spring pack was dirty. Like, really dirty. So I cleaned all that out, switched back to the old reg piston, and presto! everything works great.

Not sure yet if it was the Level 10 reg piston or the dirty spring pack. Might never know. I'm just glad to be done with it.

[Nobody]

It is far harder to diag a problem when the gun is not in your hands, even with vids. Lots of things that people will take for granted or already expect, but you can't see. The end result is that it is working and that is the only thing that matters. And you know more about your gun than going into it.