Air Venturi AV Avenger “under charging”

I have an Air Venturi Avenger 22, bought refurb from Pyramid Air a couple of years ago. I’ve been very happy with it so far. Took it out of the gun safe a few days ago for some target shooting and my compressor won’t charge it past 3000 psi. Put a plug in the end of the charge hose and it goes right up to 4,000 psi no problem, so the problem is in the gun and not the compressor. The gun still shoots fine at 3000 psi, and holds a charge no problem too.

When charging, the pressure gauges on both the compressor and gun agree on 3,000, but it never gets higher. I guess I’m looking at a small leak somewhere on the gun. Any clues where to look?
 
I have an Air Venturi Avenger 22, bought refurb from Pyramid Air a couple of years ago. I’ve been very happy with it so far. Took it out of the gun safe a few days ago for some target shooting and my compressor won’t charge it past 3000 psi. Put a plug in the end of the charge hose and it goes right up to 4,000 psi no problem, so the problem is in the gun and not the compressor. The gun still shoots fine at 3000 psi, and holds a charge no problem too.

When charging, the pressure gauges on both the compressor and gun agree on 3,000, but it never gets higher. I guess I’m looking at a small leak somewhere on the gun. Any clues where to look?
Yet it doesn't slowly fizzle down when you charge to 3000? First id assume one of the gauges is screwed. Then id assume maybe a regulator issue. Maybe it's inappropriately venting when there's 200 bar on the reservoir side? My first worthless thoughts
 
Could be leaking right where the compressor connects to the gun. Just because the dead head plug isn’t leaking doesn’t mean it isn’t leaking when on the avenger fill nipple. Way to check that is (be very careful!!) when it stops filling shut the compressor off completely and check for leaks at that junction. JUST REMEMBER TO BLEED THE LINE BEFORE RESTARTING ThE COMPRESSOR. This will narrow it down for sure if it’s in the gun.
 
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Yes, the gun holds the 3000 psi charge for multiple days, no problem. The check valve appears to be working normally: pressure builds relatively rapidly on the compressor gauge until it exceeds what’s in the gun, then a slight dip when the check valve opens, and pressure continues to build a bit slower, until about 3000 psi on both compressor and gun gauges, where it stalls

I’ll try some of the leak snooping checks mentioned. I’ve seen mention on here of charging the gun with it in a “cocked” state, so the regulator is at pressure. Is that a standard procedure that I was unaware of? I’ve always charged it in a de-cocked state in the past.

Also saw someone that mentioned that they couldn’t get the gun fully charged until they raised the regulator pressure. Not sure why that would be. I have not messed with my regulator pressure since I initially set it.
 
Yes, the gun holds the 3000 psi charge for multiple days, no problem. The check valve appears to be working normally: pressure builds relatively rapidly on the compressor gauge until it exceeds what’s in the gun, then a slight dip when the check valve opens, and pressure continues to build a bit slower, until about 3000 psi on both compressor and gun gauges, where it stalls

I’ll try some of the leak snooping checks mentioned. I’ve seen mention on here of charging the gun with it in a “cocked” state, so the regulator is at pressure. Is that a standard procedure that I was unaware of? I’ve always charged it in a de-cocked state in the past.

Also saw someone that mentioned that they couldn’t get the gun fully charged until they raised the regulator pressure. Not sure why that would be. I have not messed with my regulator pressure since I initially set it.
The gun only needs to be cocked to fill from a completely empty state.
 
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Why is that? Can you expound on that?
When there is no pressure in the reservoir, the poppet valve has no pressure keeping it closed other than the return spring, the hammer will be pressing on the poppet valve pin holding it open because the hammer spring is much stronger than the valve spring. Once there is a couple BAR in the tank the poppet will be able to counter act the resting pressure of the hammer spring.
That's the best I can explain it.
 
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just a weird question , are you looking at the right gauge there are two opposite sides. My averger came with the reg set at 2900 psi
Yes. I’ve owned the gun for a couple of years now, and it has run fine up until now. I lowered my regulated pressure down to about 1600 psi back when I got the gun, for extended number of shots (indoor target range). During troubleshooting this pressure loss problem I did raise the regulated pressure to 2000 psi to see if it would make a difference, but it didn’t.
 
When there is no pressure in the reservoir, the poppet valve has no pressure keeping it closed other than the return spring, the hammer will be pressing on the poppet valve pin holding it open because the hammer spring is much stronger than the valve spring. Once there is a couple BAR in the tank the poppet will be able to counter act the resting pressure of the hammer spring.
That's the best I can explain it.
Thanks. That does make sense.
 
Tried a few things yesterday.
Tried charging with the gun cocked. No difference.
Tried raising the regulated pressure. No difference.
Tried degassing the gun and recharging. That did make a difference for the worse. After degassing, it would only charge up to 2000 psi and then stalled there, so I made it worse.

Spoke to tech support at Air Venturi about it and he made some suggestions. The first was to try putting a couple of drops of silicone air gun oil (which I already had) in the end of the charge port. The idea was to get the oil dispersed inside to wherever the leak is, as it might help seal it up. I did that and was back to being able to charge it up to 3000, so whatever leak I caused by degassing sealed up, but the original leak rate is still there.

I’ll remove the stock and fore stock today and do the full snoop test while the compressor is running (and leaking) at 3000 psi to see if I can localize the leak.
 
Tried a few things yesterday.
Tried charging with the gun cocked. No difference.
Tried raising the regulated pressure. No difference.
Tried degassing the gun and recharging. That did make a difference for the worse. After degassing, it would only charge up to 2000 psi and then stalled there, so I made it worse.

Spoke to tech support at Air Venturi about it and he made some suggestions. The first was to try putting a couple of drops of silicone air gun oil (which I already had) in the end of the charge port. The idea was to get the oil dispersed inside to wherever the leak is, as it might help seal it up. I did that and was back to being able to charge it up to 3000, so whatever leak I caused by degassing sealed up, but the original leak rate is still there.

I’ll remove the stock and fore stock today and do the full snoop test while the compressor is running (and leaking) at 3000 psi to see if I can localize the leak.
Did you by chance lower the pressure when the gun was full?
 
Alrighty then… mystery solved. I’ve got leaks from both air tanks. The main tank is only leaking at the receiver end (fill end is fine) but the little expansion tank underneath it is leaking from both ends. Took things apart and only managed to make the leaks worse. I guess I’ll be looking for a reseal kit.

All of these seals are pretty firm and plasticky, not rubbery, and are flattened / squared off, not shaped like typical o-rings. Is that how they come, or part of the problem? Anyone know of a tutorial on doing all of the seals? The ones inside of the tubes look like they might be tricky getting off and on.

edit- just dropped in to Captain o-ring and it looks like all the o-rings have normal round cross sections. I guess the rings getting hard and square is part of the problem.
 
Alrighty then… mystery solved. I’ve got leaks from both air tanks. The main tank is only leaking at the receiver end (fill end is fine) but the little expansion tank underneath it is leaking from both ends. Took things apart and only managed to make the leaks worse. I guess I’ll be looking for a reseal kit.

All of these seals are pretty firm and plasticky, not rubbery, and are flattened / squared off, not shaped like typical o-rings. Is that how they come, or part of the problem? Anyone know of a tutorial on doing all of the seals? The ones inside of the tubes look like they might be tricky getting off and on.
Sounds like delrin seals. Are they about 3.5 mm thick, white, with a small hole in the middle, like this?
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