On/Off leak, is the pin too short?

[automikey]

I built myself a custom mag with a RPG shadow rail (I think) which had a sear installed, ULE body and an older single trigger composite frame. Then I took the X-valve out of my Tac-One and installed it. I'm pretty sure I have the ULT in there also. I put a full 13/3000 HPA tank on and if I remember it shot fine when full, but before long I noticed that there was a leak around the trigger area. If I tap the trigger a few times very lightly the leak will stop (tap too hard and it fires..).

I thought I heard once that the sear and on/off pin should stay together when switching valves.

Do I need a longer pin?

[Coralis]

typically a leak like that is an oring/oil problem too short of a pin will cause the gun to be overly reactive/auto fire

[athomas]

If it is physically leaking into the rail-frame area, then the pin length is not the issue. You have a leaking oring. It is either the small black one inside the on-off assembly or the larger white one around the base of the on-off assemby. If tapping the gun causes it to fire, then you probably need to remove a ULT shim. This will allow the on-off pin to push the sear farther up on the bolt and help prevent misfires.

[automikey]

If it is physically leaking into the rail-frame area, then the pin length is not the issue. You have a leaking oring. It is either the small black one inside the on-off assembly or the larger white one around the base of the on-off assemby. If tapping the gun causes it to fire, then you probably need to remove a ULT shim. This will allow the on-off pin to push the sear farther up on the bolt and help prevent misfires.

Thanks, it sounds like an o-ring leak. Tapping the trigger makes the leak stop a little more each time you tap it (for 3-4 taps), until you tap it to the point where it fires.

I just don't remember this problem with the Tac-One that I took the X-valve from.

[Tunaman]

Does it leak with it gassed up and the trigger held back? Is the trigger rod touching the back of the trigger when gassed up?

[automikey]

Does it leak with it gassed up and the trigger held back? Is the trigger rod touching the back of the trigger when gassed up?

Tunaman- The X-valve has about 2 cases of paint through it; it happens to be from the Tac-One I got from you probably 2 years ago. I still have it, I’m just using the valve for this other project. I’d like to get a price on another x-valve…

Regarding the current problem in this new setup:

I just tested it and this is what I found:

Leaks down the barrel when aired up (I had recently replaced the o-ring carrier(?) but perhaps I need to go 1 more size up?). The amount of leak varies after each shot, and it gets less when the tank goes below 2000psi, but it’s usually there.

Pull and hold the trigger, it slowly leaks, sounds like it’s coming from the trigger area, not the barrel and not from the rear of the valve. It actually sounds like it is slowly de-gassing, like “Pssssssss” for a few seconds then it’s empty.

The rod does not touch the back of the trigger when aired up. Lots of slop in the trigger. It does have the ULT with all the little shims.

[athomas]

Leaks down the barrel when aired up (I had recently replaced the o-ring carrier(?) but perhaps I need to go 1 more size up?). The amount of leak varies after each shot, and it gets less when the tank goes below 2000psi, but it’s usually there.

Pull and hold the trigger, it slowly leaks, sounds like it’s coming from the trigger area, not the barrel and not from the rear of the valve. It actually sounds like it is slowly de-gassing, like “Pssssssss” for a few seconds then it’s empty.



The slight degassing sound when you hold the trigger is normal for a level 10 bolt. Leaking down the barrel is a symptom of a carrier that is too loose or too many shims in the powertube. Remove the shims first. Then if it still leaks, try a tighter carrier. Use the tightest one that doesn't leak.

[automikey]

The slight degassing sound when you hold the trigger is normal for a level 10 bolt. Leaking down the barrel is a symptom of a carrier that is too loose or too many shims in the powertube. Remove the shims first. Then if it still leaks, try a tighter carrier. Use the tightest one that doesn't leak.


Ahhh.. thank you very much. I'll test it out later today.