Leaking very fast from air cylinder, Gen4 Vulcan.25
Hi all, this is my first post, although I have been lurking long time on this board. I am new to Vulcan but have been shooting other airguns like RWS springer and HW100 .22 PCP.
Bought a Vulcan .25 from Tony. It’s my first .25, went through about 2-3tins of JSBs, it has been great, until it start dumping air through a vent hole.
Couple weeks ago one afternoon after some plinking I was filling the gun, when the fill pressure reaches 200bars or higher, the air start to leak out quickly through a tiny vent hole about two inches from breech. There are two holes, the air is coming out from the one slightly further away from breech.The leak was so fast that I could see some grease/silicon was blasted out by the air. It was a hot day, perhaps the grease was thinner and start to flow a bit.
Filled to 200bars I can still shoot it, It is holding max 200 Bars overnight without problem, but if I fill it any more than that, air will leak out from the vent hole.
I wonder if any one else having same issues, I did see someone posting a similar problem but not exactly the same, his was leaking down to zero.
After searching the forum and watching some youtube vids, I ordered some O’ring,s will try to investigate inside of the gun. I am guessing mine is leaking around the outside of reg, since my leaks start at 200Bar, way pass the aprox~150bar of the reg setting.
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Thank you for the advice Greg!
I did talk to Tony and he is cool about I servicing the O’rings. I plan to change them all while have the system open.
This forum is great, full of resources and help, after reading some helpful posts, I also plan to drop reg pressure and reduce the MV to about 880fps with 25gr JSBs.
:8:
It could be the hi pressure side outside O-ring or the small one on the inside.
You could just change out the outer ones and see before having to deal with the inners of the reg.
If so, I’d change out ALL of them and be done with having to go in time after time is just second guessing.
A leak out of this second hole is the hardest to figure out and can be anyone of the O-rings of the reg that’s at fault.
It’s up to you but you could also opt to send it back to Tony, but it’s just a matter of time one needs to fix a leak.
But, just in case it gets compacted for yah ….. do ask Tony first before taking it to bits if it’s okay.
~ Greg
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Went through the process, took apart the air tube and replaced the O’rings. Although the O’rings look like still in good shape, I replaced them anyway.
There is something strange about the position of the regulator, when i took off the valve and look inside, saw the regulator was not sitting exactly straight in the middle of the tube, it is slightly cocked from the axis, almost like the regulator diameter is a bit too small which allows the assembly to rotate around the cross-section. Imagine if you cut the tube and reg vertically, it would look like this: |\\|
Instead of O’ring, the metal of the regulator is touching the inside wall of the air tube, it is a bit concerning because I can see some markings on the tube wall where regulator contacts the tube, I think that’s the leaking location. I assume the marking was made when assembled in factory. There are also contact mark on the reg body as well.
By the way there was a LOT of factory grease in the tube and on the Oring’s location. I cleaned the tube and re-lube everything, carefully put in the regulator, made sure it is straight and square. and re-assemble the whole thing. Filled to 240 bar, so far pressure is holding, will check tomorrow to see if there are any slow leaks.
Note to self, couple of things need caution:
After tighten the barrel/tube clamp, I could still feel the barrel moving when cocking, so I gave the clamping screw another twist, STRIPPED the aluminum nut! :sadn:
I took the opportunity to decreased regulator pressure by aprox.1/8 of a turn, used a needle nose plier as spanner wrench to open the regulator, it is hard to hold and easy to slip, and I made a scratch on the reg 😐 It does not affect the function but sure was a moment I wanted to kick myself. :cry:. Edit: As Kris pointed out, adjusting reg pressure does not need opening the reg body, I did so to replace the inner o’ring.