FX Impact leak….part 2. It's back…

Forums PCP Airguns FX Impact leak….part 2. It's back…

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    AirSupply
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    If it’s out the tp it is the valve seat. They can reseal seal even when the metal of the valve seat has cracked. Then you start shooting and eventually it will leak again 

    If the leak is pressure related and leaks more at lower bottle pressure then that could be the regulator.Regulator leaks in my experience tend to just let go and leak not reseal. 

     The only other place that shooting the gun may make it leak  because of the movement of the valve rod is the oring around the valve rod in the plenum. It is more reliable since it was upgraded from a small xring to a larger oring but will wear and go eventually. 

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    stoti
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    I checked the valve seat and valve housing three times over the last few days and today with a flashlight and magnifying glass. The metal looks pristine and I changed the o-ring, but it looked fine too. It seems to leak at higher pressure, not lower pressure. I inspected the valve rod and the O-rings inside the valve tube today very closely. The  larger o-ring you're speaking of looked fine too. It seems as if the leak coming out of the transfer port has to be related to the valve tube, valve housing or valve seat but everything looked in perfect condition. Like I said, I changed quite a few O-rings, maybe that's why I can't get it to leak? I'm not getting my hopes up though, I was at this exact same point yesterday and the day before, then I started slug testing and heard the dreaded leaking sound. I'm hoping for the best because I don't know what else to do. Thanks. Stoti

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    Scotaty
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    Probably like what some guys said it's the delrin in the valve rod doesn't always seal the valve seat. You can also check B23 it does the same thing. 

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    far_shot
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    That's a pretty healthy leak! Valve seat slightly cocked? Valve rod rotating with many hammer strikes till it sets in a spot where it will leak? Ernest has a heavy duty valve seat that cures cracks and breakage. Grease on the valve rod(reaching here). I'd go with that new  seat and a new valve rod.
    From there….beats me too :(

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    Airgun-hobbyist
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     To get the speed you shooting at, did you by chance preload the hammer spring? When I preloaded the hammer spring screw on the adjustment wheel and took off the bottle sometimes all my air would leak out at the valve stem seal.  I could only get it to seal and accept air within the system from a new bottle by first turning the wheel to it's lower settings to relieve the valve stem rod and hammer spring assembly of the preload before screwing on a bottle.  Sounds to me like something is not allowing the valve seal to do it's job, like too much spring pressure, or not enough return spring pressure.

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    stoti
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    I inspected B23 and B24 closely and the small black Delrin washer on the valve rod too. I spent a lot of time inspecting everything related to the valve tube, rod, housing and seat. I guess deep down I'm hoping one of the O-rings I changed or something not being perfectly in place was the issue and I'll be done with it. I'm not getting my hopes up although I have shot like 150 rounds testing it this evening and it won't dump air like it has been. I'm sure it will tomorrow when I go to test slugs! LOL

    Thank you! Stoti

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    Airgun-hobbyist
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    One way to test my above theory is if it starts doing it again, fire a shot off, and immediately turn the knob from Max (or wherever you have it set at) to its lowest settings, then take another shot to see if everything seals with no additional spring preload.

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    stoti
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    I'll definitely try that tomorrow! Today when it happened I fired 6-7 more shots and it wouldn't seal. Once it started, nothing I did could get it to stop. At this point, I'll try or do anything if it gets me any closer to finding out what's going on.

    You know, my gun never did this and I shoot it a lot. It started right after I started testing the slugs. I did turn up the hammer spring pre-load right before I started testing slugs because I knew I was going to need more power. Could be??? Thanks, Stoti

    p.s. I just backed off my hammer spring pre-load about 1/2 turn to where it was before all of this began.

    • This reply was modified 5 months ago by stoti.
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    heavy-impact
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    Airgun-hobbyist

     To get the speed you shooting at, did you by chance preload the hammer spring? When I preloaded the hammer spring screw on the adjustment wheel and took off the bottle sometimes all my air would leak out at the valve stem seal.  I could only get it to seal and accept air within the system from a new bottle by first turning the wheel to it's lower settings to relieve the valve stem rod and hammer spring assembly of the preload before screwing on a bottle.  Sounds to me like something is not allowing the valve seal to do it's job, like too much spring pressure, or not enough return spring pressure.

    You can get around all that by holding the cocking lever back just where you feel some tension while you screw the bottle on. Once the pressure hits the valve it stays sealed.

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    edosan
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    heavy-impact

    If it leaks out of the transfer port it can not be the regulator. As rc-air mentioned it could be the valve rod not being perfectly straight.

    Actually it can, when you degas the regulator the air goes that way through the barrel when the bottle is there. 

    Inspection need to be made. 

    • This reply was modified 5 months ago by edosan.
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    heavy-impact
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    edosan

     

    Actually it can, when you degas the regulator the air goes that way through the barrel when the bottle is there. 

    The valve/valve seat o-ring and second o-ring from the rear of the valve housing are the only avenues for pressurized air to enter the transfer port. The valve is held shut by regulated pressure and remains closed as long as pressure is present. I can't think of a way to depressurize the regulator with a charged bottle engaged. There are no other passages into the transfer port or barrel. Please explain.

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    edosan
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    Try this, take the bottle out, depressurize the reg and put a finger sealing the bottle plug/insert and see where the air goes

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    heavy-impact
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    edosan

    Try this, take the bottle out, depressurize the reg and put a finger sealing the bottle plug/insert and see where the air goes

    I'd like to try but my Huma reg doesn't depressurize like the FX one did. When turned up without a bottle it does nothing. It's a moot point though because stoti has a pressurized bottle engaged when his problem occurs. I'm just like him in wanting to know why it leaked even if the leak stops.

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    edosan
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    Your idea or a stethoscope with a small hose is a pretty good one.! 

    Not saying is an oring on the reg, but it might. When I do what I mention with the fx reg, the air goes out all the way through the barrel, and if the pellet probe is back, goes out where stotis video shows. We are all just trying to help 😉✌️ 

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    stoti
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    This morning I got up, ready to go shoot and the gun was completely empty of any air. I went to bed with it showing about 240BAR. This morning 0.

    I filled it with air…tried anyway and as soon as air went into the tank, it poured out the transfer port. I tried cocking the gun or holding the cocking lever back, made no difference.

    I also turned the power wheel to minimum, cocked and fired the gun a few times, made no difference. The air just kept rushing out of the TP. 

    I'm so frustrated that I really don't feel like messing with it right now but at some point today I'll have another go at it. I'll have a look at the regulator.

    Thanks for all of the help guys!

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    OrdnasNS
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    Sorry to read that your gun is empty again. If there is bad regulator it will leak on breath hole or it will transfer bottle pressure in the plenum chamber so I think reg is ok. You have problem with valve seat, valve seat o-ring or valve rod delrin and maybe with valve housing.

    Is it possible that when you were maintaining the gun you accidentally scratched surface where VS seats in valve housing so o-ring is ok for some time than starts to leak?

    Are you sure that delrin on valve rod is undamaged and perfectly seated in VS, is it flush at the back of the block in the beginning and after few shots when leaking starts?

    Is a valve rod undamaged and straight?

    Is valve housing all god in area around VS, not broken or damaged?

    And finally, do not get me wrong on this, is valve seat set in valve housing in the correct way? 

     

    BR

    Sandro

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    stoti
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    Everything you've mentioned has been inspected under a bright light and magnifying glass. I initially and still kind of think it has to be in the valve system somewhere. Everything is undamaged and installed correctly with great care. I appreciate your imput, everything you mentioned has been inspected including the valve rod, although I didn't roll it on a table to check straightness. Today I'm going to take out the regulator and inspect it for any areas that look like they could be causing the problem.

    This is interesting though…

    I filled the gun yesterday after putting it back together, I shot it probably 100 times trying to get it to leak for me. I shot fine, no leak.  I re-filled the  gun to 250BAR and shot a few more times before bed, no leak. I put the gun away last night before bed and this morning it was at 0BAR. I tried to fill it up, but as air went into the tank, it rushed straight out the transfer port. It gained a little pressure over time so I disconnected it and tried a few shots to get it to seal, it would not.

    So, when I put the gun away last night, it was sealed at about 240BAR and not leaking, at some point, without shooting it, it started leaking again and dumped all the air down to 0BAR. I mentioned it earlier, when the gun empties, it doesn't just empty to 40BAR or so, it empties to 0, all the air in the valve tube is drained too. Not only that, something caused the seal to start leaking in the middle of the night even though it was under pressure, sealed and I hadn't shot it. Doesn't that seem a little strange? The fact that it leaked all of the air, including the air in the valve tube which should be a closed and sealed area. Also, isn't it strange that it started leaking in the middle of the night without me shooting it? It was sealed and holding air when I put it away, what would cause it to start leaking while it was just sitting?

    I'm just trying to put any information I have out there so I can find this leak by Monday. If not, I'm going to have to send it in and let someone more knowledgeable than me figure it out, Thank you for your help. Stoti

    • This reply was modified 5 months ago by stoti.
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    OrdnasNS
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    The only thing beside valve seat and valve rod delrin that pops to my mind is B29 o-rings 10,5×2 nbr70 on the outer surface of the valve house. If second from the back side (there is four of them) is not perfect or the grove in which he sits or the surface of the rear block is scratched it could cause leak thru transfer port into the barrel. That one and the next to the front side of the gun seals the part of the block where pressure gauge get air to measure the regulator pressure. Do you by any chance have spare valve seat and valve rod to put in the gun?

    Excuse me for my writing, English is not my native language.

    BR

    Sandro

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    Airgun-hobbyist
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    Ok, so lowered hammer spring tension didn't work.  The next common leak through this area is for the older valve seat's to crack and leak.  Remove the valve housing and then remove the valve seat, and o-ring.  The valve seat probably has a small crack somewhere around the o-ring's groove.  Until  the back of the valve seat breaks completely off, the leak can be intermittent.

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    stoti
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    I did that yesterday… I took out the valve seat and inspected it under a bright light and magnifying glass. No cracks and I replaced the O-ring.  I also replaced all of the O-rings on the outside of the valve housing. It still leaked last night. Starting to see why I'm so perplexed?

    Thanks again, Stoti

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