FX M3 leak issue I can't find

[JJZatgun]

I have an FX M3 I bought last May 2022 and I have been dealing with a recent persistant leak issue. The gun is losing about 100 - 125 psi everyday, I've used leak detector spray all the known areas that could ne leaking, and I could not detect any bubbling or fizzing sounds. The one possible clue is when I remove the air bottle, after a half hour to hour, the plenum will suddenly discharge its air in about 10 seconds back out the bottle adapter/first reg.
Does this mean there is a leak in the valve inside the plenum? and what are the solutions.

I'm prepared to take the plenum assembly apart if necessary and to examine all the o-rings and valves.

 

[xyon]

I have an FX M3 I bought last May 2022 and I have been dealing with a recent persistant leak issue. The gun is losing about 100 - 125 psi everyday, I've used leak detector spray all the known areas that could ne leaking, and I could not detect any bubbling or fizzing sounds. The one possible clue is when I remove the air bottle, after a half hour to hour, the plenum will suddenly discharge its air in about 10 seconds back out the bottle adapter/first reg.
Does this mean there is a leak in the valve inside the plenum? and what are the solutions.

I'm prepared to take the plenum assembly apart if necessary and to examine all the o-rings and valves.

No it does not mean the leak is anywhere in particular. The plenum will discharge once the pressure has dropped enough to open the reg. Have you checked the valve for a leak. You won't see that with the spray. With the probe closed the air would come out the muzzle.

 

[Thach2264]

Send it in and let FX deal with it.

 

[Quagmire]

My early M3 was leaking from one of the four trigger guard screws due to an internal manufacturing defect. Like you described, I had a very hard time finding my leak as it wasn't in a common area.

 

[Airgunmann]

Put a balloon over the muzzle see if it fills up can also be leaking at a gauge out the hole in the back of the gauge