FX Crown CF Bottle O-Ring Leak

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mtnGhost

mtnGhost

Member
Dec 15, 2018
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Defected from the PNW, United States
The other day, I noticed my bottle was "popping" as I removed it from my Crown. It was the sound like an o-ring getting destroyed, something that I was all too familiar with the RAW.

Anyways, I looked inside of the bottle opening and I can see a fat o-ring that looks kind of shredded. I have no idea how or why this thing crapped out, but my question is are these seals replaceable? If so, does the entire valve need to come off of the bottle (I.e, with a C-spanner?)

It's not the metal dowty seal, I have no idea what the o-ring size would be - the schematic just shows the bottle as a single unit. I'd love to figure this out, including the o-ring spec (I read somewhere that there was a 9.3x2.4mm duro 90, but I'm not sure if that applies to this or not).
 
If the bottle leaks: Might be that, go 3 or 3.5 mm better (a caliper is much better to get o'ring measures without the need of search on manufacturer datasheet, if exists, sometimes there is no other option either way jaja), 70 harness is fine too (on the number 5)...but also might be the valve pin ... I had the same problem on one of my new 580cc valves, and was / is the valve pin seal (almost identical to the crown valve pin but smaller ... same principle) new valve cost US$60 btw
 
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https://fxairguns.com/wp-content/uploads/2019/02/Bottle-Drawing-and-Partlist.pdf

1565356419_19957103885d4d7183bb4717.61248779_5B06B646-59BA-49C7-B1F2-D3E00756FAE7.jpeg
1565356419_2350383335d4d7183e72ea1.88016843_4BBB4629-973A-455F-A841-4E4D1083FFAE.jpeg

 
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If the bottle leaks: Might be that, go 3 or 3.5 mm better (a caliper is much better to get o'ring measures without the need of search on manufacturer datasheet, if exists, sometimes there is no other option either way jaja), 70 harness is fine too (on the number 5)...but also might be the valve pin ... I had the same problem on one of my new 580cc valves, and was / is the valve pin seal (almost identical to the crown valve pin but smaller ... same principle) new valve cost US$60 btw
Click to expand...

I had this happen already twice! I suspect there's some fine particles that can get in through the hole where the valve pin faces the muzzle😬
 
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Me too, it was the vs oring, no leaks now!

That is the crown pin? The one on the bottle does not have that small oring (at least in mine)
Click to expand...

OHHHH I see now, that's the bottle valve pin you posted a photo of! No, the pins in the photo I posted was the Crown's actual valve pin in the action. The bottle pins will be the same I'm sure.

Also, my rifle leaked again overnight. I think it's the VS o-ring, but my bottle threads are f'd up now on my Continuum somehow! Almost like it wasn't double threaded. Those bottle threads must be stronger than the threads on the bottle adapter's threads, because not both my Crown's bottle adapter threads are f'd up since I swapped bottles to test for leaks 😬

  • Repairs now: replace bottle adapters on both rifles
  • Replace bottle threads on both bottles

Edosan - did you use a C-spanner to get the bottle apart?


 
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Edosan – did you use a C-spanner to get the bottle apart?

Man, this was a two part fail. First, the 9.3mm bottle o-ring was definitely leaking. Then, I saw that my Ti VS had a little nick in it.

This VS was 6.5mm, I swapped it with another VS (6.35mm) and one of the new UMHW sealing valve pins - and interestingly, my velocity increased by 30-40fps! 🤔
Click to expand...

Miss that, sorry, no, I use a common pipe wrench and something soft to avoid scratches (fail on that jaja) and butane , but a C spanner is a better tool for it.

weird about the speed increase with a lower size bore, I can think in 2 things (but I might be wrong), with the 6.5mm VS the seal is too small for the crown (have you measure it?) but enough to make a seal (or maybe not) so it get a bit, but just a bit stuck in the bore (so you need a bigger umhw or acetal seal, IME 0.4mm larger is too small, 0.5mm larger is almost exact, and 0.6mm larger is fine ), or you need more strike force to open the 6.5mm bore. Donno just ideas.

The 6.5mm VS is tapered 1 or 2 sides? pics?

Just read in another thread you say 6.57mm bore on the VS, if the seal is 7mm is too small 100% sure. It hapend to me before. (leak and stuk)
 
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I have 3 titanium valve seats total, 2 are 6.35mm and one is like 6.57mm. All 3 are tapered on just one side. I put the flat side facing the breech.

The leak is still there. If it's coming from any of the areas where I can test with bubbles, then it's not fast enough to cause the bubbles. I might have to try the bad trick to try an isolate the area where it's leaking, not fun.

RE: speed increase - it turned out to be 20fps. I trust my Caldwell for MV data over my LabRadar, but it was still a noticeable gain. I might just be from the pin 🤷‍♂️ 
 
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Pin is my bet on that gain.

Double tapered vs are more prone to get a rod seal stuck if is too tight fit

Have you touched the gauges? I remember I had one and was gauge that needed to be about 2mm tight, I had to submerged the impact in a 5g bucket to find out (I was pissed! And make a full oring change and still leaking) was like 1 bubble every 5 seconds..
 
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Pin is my bet on that gain.

Double tapered vs are more prone to get a rod seal stuck if is too tight fit

Have you touched the gauges? I remember I had one and was gauge that needed to be about 2mm tight, I had to submerged the impact in a 5g bucket to find out (I was pissed! And make a full oring change and still leaking) was like 1 bubble every 5 seconds..
Click to expand...

Yeah, unfortunately I took the gauges off Saturday (first time on this rifle) to put it in a vise to get the bottle adapter off. The rear gauge has a different orientation now, like not turned enough. I had put a fat o-ring under it to align the gauge, but I took it out after I lost 40 bars over night. I tightened both as tight as I could without damaging them, still have this leak!

I guess I need to strip it down to all but the valve, bottle and gauges and submerge it! 🤔
 
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