FX IMPACT barrel inlet leak

[tomhu0918]

Hi Guys,

I found my barrel inlet is leaking the air. And check the FX trouble shooting manual. It said that was main valve(7064)/valve seat(19202) problem.

I replace all the valve housing(B29 & B29.1) & valve seat oring and rod oring(2.2x1.0).



But it still is leaking. I even changed the new valve housing and valve seat. It doesn't work.



Please help.

 

[Airmanator]

The only way it is leaking from there is the valve seat o ring. When you install the valve seat your probably Nick bits of the o ring off when you push it into place. It's common. It's really hard not to Nick the o ring when installing it. I Nick a few o rings trying to get the valve seat in. Use a Dremel to round off the valve housing where it make contact with the valve seat o ring. It makes life much easier to install the valve seat.

 

[edosan]

It can be the VS oring as mentioned or can be the VS seal against the Delrin in the rod. Is the VS a stock one or did you replace it? If is not a stock VS might be a defect on the new VS. 

 

[tomhu0918]

Yes, I replace the stock 5.5mm VS to 6.0 VS.

And I found the leak. So I switch back to the stock VS. Then both were leak now.

 

[Airmanator]

I used 6.4mm valve seat with stock rod and first time I put everything back. I shot it work fine. But when I put the gun away, I could hear a hissing sound. I listen to both gauge, I finally found it was coming from the barrel. So I knew it was coming from the transfer port. I took everything off and check valve seat o ring. They had tiny pieces cut off from the o ring when I was installing it. I replaced the o ring with a new one. When I try to push the valve seat into place. It would catch in the corner crushing the edge of the o ring. There was no one to install the o ring back in without nicking parts of the o ring. So I had to grind the edge where the o ring meets. Round it off and had no problem installing the valve seat. I put everything back and no more leaks. So I can tell you 6mm valve seat will work fine. Max size for valve seat is 6.5mm. I think your problem is when you took it out and reinstalled it. You nick pieces of the o ring. And when you switch back to the stock valve seal. You also nick it too. That's why its leaking for both now. Find a new o ring right size and round off the edge of the valve housing to make installing valve seat easier. 

 

[edosan]

if you are positive that is not the VS o'ring, might be a leak in the delrin seal, did you try to dry fire a few times? to see if the seal get better

Also might be a problem with the 2 orings on the ValveHousing near to the transfer port (not sure but might be worth to check them or replace them)

 

[heavy-impact]

Be sure you install the valve seat with the o-ring closest to the rear. If you put it backwards it will leak.

 

[INSIX]

Good information to note. I love my Impact but thank goodness I have another airgun; as its always in maintenance mode. 

 

[heavy-impact]

I don't have any problems and it only takes one shot to get the job done.

 

[tomhu0918]

Hello Everyone,



After i made a lot of try & error. I found out it was not oring's problem.

Mr. Edison is correct. The valve plug did not seat on the valve seat. So it caused leak.

So I turned the valve knob to full close. That made the valve rod to push the valve seat. Then no more leak.



BUT, there are new problem. I found every time I removed the bottle to depressurize. The valve rod moves to the valve knob side and the valve can not touch the VS.

It's hard to explain. I make a vedio to show that:



1.This is bottle on and pressurize. Turn the valve knob to full close. And turn the valve knob open. No more leak.

https://youtu.be/v6lKW841qkQ



2.This is depressurize without the bottle. You can see even I turn the valve knob to close. The valve valve did not stay on the VS.

Even dry fire also.

https://youtu.be/EePp7Di6AkY

 

[heavy-impact]

Hold the cocking lever back to where you just feel tension as you screw the bottle on to keep the valve seated. No need to touch the valve stop.

 

[edosan]

are you using a C3 bumper delrin and a hammer weight? looks to me those might be the ones giving you problems, too thick both (c3 bumper and head of the hammer weight). Your valveRod is not seated ok (must be fully seated before adding air) and you need to force with the valveKnob to seal.

 

[tomhu0918]

Hello,



I guess I found out what's the reason cause this problem.

It's the plenum. When the plenum was installed. And you depressurize the the bottle. The plenum will create a vacuum space.

That suck the valve rod out of normal position.

When I removed the plenum and only installed the gauge. Everything went back to normal.

https://www.youtube.com/watch?v=tZGS-f9Bbss&feature=youtu.be



So it was vacuum to let the valve doesn't seat on the VS while out of pressure.



Thanks for everyone provide your valuable experience to share.

 

[Airgun-hobbyist]

Two ways to allow the valve to seat. You can do like Heavy-impact says with the cocking lever, or alternatively, you can turn the hammer spring adjustment wheel to 1 so it lets tension off the spring. I learned with my ImpactX to turn down the power wheel, but Heavy-impact's way will work well also if you have a lot of preload tension on the adjuster.

 

[edosan]

So it was vacuum to let the valve doesn't seat on the VS while out of pressure.

Could be plenum related but vacuum do not think so. There are hundreds of installs with external plenums and no one have issues like that. I have installed dozens and no problems, so I do not believe is Vacuum related

BTW is edosan not edison (I know, the corrector)

 

[heavy-impact]

So it was vacuum to let the valve doesn't seat on the VS while out of pressure.

Could be plenum related but vacuum do not think so. There are hundreds of installs with external plenums and no one have issues like that. I have installed dozens and no problems, so I do not believe is Vacuum related

BTW is edosan not edison (I know, the corrector)

I agree with Edison 

that it can not be vacuum. It's a poppet valve so there is nothing for vacuum to act on.

The hammer spring preload is overpowering the long valve rod spring that holds it shut.

 

[edosan]

Hello Everyone,



After i made a lot of try & error. I found out it was not oring's problem.

Mr. Edison is correct. The valve plug did not seat on the valve seat. So it caused leak.

So I turned the valve knob to full close. That made the valve rod to push the valve seat. Then no more leak.



BUT, there are new problem. I found every time I removed the bottle to depressurize. The valve rod moves to the valve knob side and the valve can not touch the VS.

It's hard to explain. I make a vedio to show that:



1.This is bottle on and pressurize. Turn the valve knob to full close. And turn the valve knob open. No more leak.





https://youtu.be/v6lKW841qkQ







2.This is depressurize without the bottle. You can see even I turn the valve knob to close. The valve valve did not stay on the VS.

Even dry fire also.





https://youtu.be/EePp7Di6AkY

good videos BTW!

 

[tomhu0918]

After thinking, I agree that it is not the vacuum.

I will try to find out what's the real reason.



Will update the result.

 

[bucketboy]

Is your hammer spring too strong or too long holding the valve open?