Tuning Air Venturi Avenger Leaking at fill nipple when filling with hand pump

[dr.matthew]

I recently purchased an Avenger and it has been great but developed a leak around the fill nipple when I tried to refill it with the hand pump. At first I thought it was my handpump quick connect fitting, but after purchasing the specific one for the Avenger it still leaked. I recently bought a nicer pump from Air Venturi but it still leaks at around 3000psi. Does anyone have an idea of what might be the issue and how to solve it?



Thanks.

 

[Odoyle]

Is it leaking through the center hole in the nipple or the threads? Soapy water check?

 

[FuzzyGrub]

I think you are saying that the gun is not leaking down. It is leaking at the male foster when you get to 3K psi, from the pump strokes. correct?



Looking at the Avenger schematic, it looks like even though NV changed to the male foster from the probe of the Liberty, they retained the spring and ball style check valve. I had problems with those. At higher pressures, I'd have 500psi more on the fill, than on the gun. I've heard of the ball getting stuck in the O-ring, too. I'd degass the gun and take that apart, clean, and check the condition of the related O-rings.

 

[dr.matthew]

Correct It holds full pressure when filled, but when I am in the process of filling the gun with the pump it leaks at 3k. I will degass and clean the valve and see how that works. 

Thank you for your helpful and speedy response.

 

[dr.matthew]

Odoyle

Is it leaking through the center hole in the nipple or the threads? Soapy water check?

It leaks at the threads of the fill nipple.

 

[Batman2]

Teflon tape on the threads.

 

[FuzzyGrub]

The fill nipple has straight threads, either M10 or 1/8 BSPP. It has a seal at the bottom that the base of the nipple compresses.

Update: Typically, the check valve is incorporated in the foster fill. This one it is down stream of it. I would replace the seal first, or sand out rough surfaces. It is typically a white plastic like seal. Worse case, you can try sealing it with tape on the male threads. I think there would be low risk of failure. It only has pressure while you are pumping. I also know that many have fixed the chinese hand pumps the same way. Good luck. 

 

[dr.matthew]

Alright sounds like a plan I'll work on that later today and report back what happens.

 

[lennyk]

oops

 

[Odoyle]

Teflon tape on the threads.

☝

 

[OTmachine]

 
If you have access to a lathe, this style seal works.

 

[dr.matthew]

I think I might contact Air Venturi and see what their policy is because it's a new gun and I don't have access to a lathe or a machine capable of fine enough tolerances

 

[FuzzyGrub]

Depending on the nipple and the surfaces, a Dowty Seal might work, and not require machining. But yes, contact AV first.



PS: If the schematic picture is correct and the fill nipple has threads (for cap?) vs wrench flats, you might need some metric jam nuts to get it out.