Leak down the barrel

[XEMON]

Hello MCB,


Dug up a project I lost interest in ...
I've had a few bumps which forced changes on this one, but I dug it up this we ... And decided to air it up for the first time since I put it away.

it's a half block midget pump with air through frame.

The cocker leak down the barrel when put 100 psi in the asa when the marker is cocked. Could it be anything else than the valve seat?

Also, if it is not cocked, it leak pretty bad with 100 psi. But that may just be there is not enough pressure holding the valve closed when the hammer is resting on it ...

Looking at it, I get motivated to finish it again ... It would be a cool open class ... Very small and light for a cocker ...

Thanks MCB,
X

[OpusX]

... it leak pretty bad with 100 psi. But that may just be there is not enough pressure holding the valve closed when the hammer is resting on it ...

I guess it isn't enough pressure in any case, the valve spring is too light, or as you stated the valve seat/cupseal is no good. If you can crank up the pressure a bit and see what happens, then you can play the springing game.

[XEMON]

I may pop a 12g in it and see what happens ...
thanks

[Jordan]

What valve do you have in it?

Some cupseal materials lose their "memory" and need to be left under air pressure for a while to seat properly, too.

[XEMON]

What valve do you have in it?

Some cupseal materials lose their "memory" and need to be left under air pressure for a while to seat properly, too.

No idea ... I'm not a cocker guy 😅
might make a delrin seal if this one doesn't work ...

[OpusX]

ewwww looks greasy. clean that up and use oil.

[XEMON]

I threw oil inside the valve in the hope of sealing it before opening it ...
I'll clean it up before closing it and throwing a 12g in.
It's a pump build so it shouldn't hurt too bad.

[Jordan]

No idea ... I'm not a cocker guy 😅
might make a delrin seal if this one doesn't work ...

Looks like stock 2k+. They're good valves but don't seal up at 100psi.

Like the others have suggested, try a higher input pressure if possible. Start at 300psi, maybe.

[Grendel]

Yup, clean it up, replace the valve body o-ring, lightly oil (Synthetic Pneumatic tool oil) and reassemble. Stock WGP valves work great down to about 250 psi below that you have to get creative with the springs to keep them sealed. There should never be grease in a Cocker valve train and that is either grease or old congealed oil.

[Alexndl]

it's a half block midget pump with air through frame.

Am I the only one that want to see a picture of that custom cocker?

[Chuck E Ducky]

To low pressure 100psi won’t do it you need enough pressure on the back of that valve to hold it close. Should just need to rase input pressure.

[XEMON]

Yup, clean it up, replace the valve body o-ring, lightly oil (Synthetic Pneumatic tool oil) and reassemble. Stock WGP valves work great down to about 250 psi below that you have to get creative with the springs to keep them sealed. There should never be grease in a Cocker valve train and that is either grease or old congealed oil.

Definitely grease ... if oil doesnt work, use grease

Am I the only one that want to see a picture of that custom cocker?

Ill save that for when i get it shooting ... but i could get persuaded

[XEMON]

Little update:

Cleaned the grease off, put it back together and BAM! It shoot!

Found 2 other small leak, but got them fixed up really fast and now it seal nice and good.

Thanks for everyone's help for my first cocker build. I put it on the scale and it comes up to 1.245Kg
light and compact, it may even take me away from my sheridans.

[XEMON]

That weight is with a stainless barrel ...

[Alexndl]

So.... we have been waiting enough?
pictures?

[XEMON]

So.... we have been waiting enough?
pictures?

Ok ... Here it is (with a 13Ci) ...
I can make a build thread with before and after if people want to ...

(PS: yes, the gauge is shot, I need to replace it ...)

[Cdn_Cuda]

It’s so tiny!

[OpusX]

Chopped hingy with a gas through mod inspired by a tippy pro-lite?! Such MCB!

[XEMON]

😋

Always wanted an air through frame (nearly bought a pre-made one) then came across the midget and saw this ...

Just bought a stainless tube to replace the flexible line ... The flop is terrible ...

Originally played with the pump assist kit, but it doesn't stop leaking ... No matter what I do ...
So got this pump kit and it matches the barrel length perfectly ...