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Fx Crown leak?

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JonasW

Member
Aug 8, 2019
51
0
Sverige
I changed transfer port to a new one with dual ports, a valve seat that's 0.25mm larger and a hammer weight.

But after reinstalling everything I only got like 5m/s or about 15fps more with the same settings. Even if the regulator is set at the same pressure and the hammer weight is untouched, I think the TP and seat should are more.

The only thing I can notice when shooting is that a puff of air comes out of the hole where you can see the valve pin. Is that normal or maybe the source of my problem?

I think this hole is normaly hidden in the stock of the Crown, so I have no reference.

1575814098_3209158805ded03d289c129.35898839_20191208_125937.jpg

 
The leak could be one of a few things

1. The new valve seat’s o-ring.

2. Normal when people install a enlarged valve seat on the FX Crown for a power upgrade, they also get or install a aftermarket valvepin which has a larger delrin plastic spring seat and possibly also made to fit the larger valve seat better. For a good sealing surface.

See pics:

Factory valve pin

1575827779_6817897045ded3943548858.99499525_C1D996F3-E4F4-49BD-984B-0176245BE0D4.png



Aftermarket or Custom made

1575827923_7698396905ded39d38249a8.15158109_FDFF01B4-214D-4950-B8B4-71EA71C47BD7.jpeg



 
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Did you replace the tiny oring on the end of the valve pin? That’s probably where it’s leaking if the only time it leaks is when you shoot. If it holds pressure when not shooting it is not the valve seat or plastic valve disc.
Click to expand...

Well that's great info! Thanks!

No I didn't replace that one. I can't hear a leak, going to check the rifle if it have dropped any since last time.
 
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Yes. If it only leaks when shooting it’s not the valve seat oring, the valve/seat, or the oring at the fitting that the back of the valve pin slides into. (I’m talking Streamline or Bobcat) haven’t had my Crown apart but I assume they are similar from the drawings). If you gun shoots fine and doesn’t leak air overnight then that small oring (1x1.5mm I think) is all it could be. Ernest has a video on identifying leaks on FX airguns. 
Mike. 
 
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Yes. If it only leaks when shooting it’s not the valve seat oring, the valve/seat, or the oring at the fitting that the back of the valve pin slides into. (I’m talking Streamline or Bobcat) haven’t had my Crown apart but I assume they are similar from the drawings). If you gun shoots fine and doesn’t leak air overnight then that small oring (1x1.5mm I think) is all it could be. Ernest has a video on identifying leaks on FX airguns. 
Mike.
Click to expand...

I agree on second thought that could be the location of the leak. The tiny o-ring.
 
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Yup. More than likely the valve seat oring due to valve not inserted evenly or fully, or perhaps the valve pin to seat joint. Either could result in a lowering of pressure slowly. There is another small 90 duro oring that the rear of the valve pin slides in and out of, plus the oring that seals the fitting to the body of the action. Best to disassemble, clean everything very good with lint free cloth, then remove valve pin and valve seat, replace valve seat oring, and carefully reassemble the rest replacing all the orings. Lightly lube all orings with silicon grease or oil as you assemble the system. 
 
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I bought a new valve pin with delrin plastic instead. Installed it and not the gun leaks out of the barrel.... :(

I reinstalled the old valve seat with the new pin and it's the same problem.

I am SO regretting buying a pcp right now.

What could I have f*cked up? I happened to screw the regulator half a turn with the bottle on when trying to empty the block. But the new amp regulator should handle that right?
 
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Have you tried to reinstall the original parts back on to replicate the original issue?

Also inspect the vale seat and the delrin on the new pin to make sure there are no imperfections on the sealing surfaces. 

If you reinstall the original parts and everything goes back to the way it was then you know it's an issue with the new parts you received. Otherwise there may be lint or something on the seats sealing surface. 

Hope you got this fixed! 
 
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I had this problem and then I put a larger delrin onto my pin and for a time it stopped. Now it is back again and I have tried two different pins and two different valve seats, including the original pin and valve seat. I still get air coming out of the barrel as soon as I put the bottle back on. I have looked for any issues with valve seat and pin o-rings, and I know that the VS mating surface are good because I used them for ages without problem. Is there anything else that could cause air to leak out of the barrel? 
 
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Hi Everyone
With my FX Crown I cocked the gun and the magazine wasn't closed properly and I may have used excessive force to close the cocking lever and the gun is now leaking badly. I filled the bottle to 200 bar and it was all gone in a couple of minutes. I'm wondering what I may have damaged? and if I can fix it myself. Thank you in advance.
 
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That’s not going to cause leaks. What else did you work on on the gun?

So based on your description, I’m imagining a mag not inserted properly or a pellet advanced into the breech properly, and you muscled the cocking lever forward anyway? We’re you able to fire a shot?

Or did you accidentally pull the trigger with the cocking linkage wide open pulled back?

It’s all in the details
 
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