Notos fill port leak

today after filling my notos, i heard a faint leak when i pulled out the fill probe. definately coming from the fill port. i left to go bowfishing and when i got home it seems to have stopped. at least to the point i cant hear the leak anyway. it is down about 500 psi. anyone know if it is very difficult to change the orings and what size they would be?.

thank you.
 
A drop, or two, of silicone oil, where the fill probe goes, may help loosen that sticky one-way valve. WM
Yes, or a couple drops down in the fill probe itself might make it more likely to get a reasonable amount of the silicone oil through the fill port. That’s another reason why a fill probe sucks. It’s much easier to get two drops of silicone oil in the standard foster fitting occasionally.
 
I haven't had a Notos apart but if it's like other Snowpeak PCPs, the fill port is a simple design consisting of a flat head screw with a flat ground on the shank, with an O-ring slipped over it. The factory O-ring is prone to extruding into the gap and begins leaking until the pressure falls enough that the O-ring material can seal again. Before long it worsens and needs to be replaced. My advice is to go back with a 90 durometer so it will resist extruding better. The factory size on my PP700S-A is an M1.5 x 5 but because of how it works, the exact size is not critical. I used a -008 to replace it...again, 90 durometer. That was 4 years and many fills ago.
 
71724219-F7A7-4EF3-9CA3-E17DFDA62DA9.png
 
I haven't had a Notos apart but if it's like other Snowpeak PCPs, the fill port is a simple design consisting of a flat head screw with a flat ground on the shank, with an O-ring slipped over it. The factory O-ring is prone to extruding into the gap and begins leaking until the pressure falls enough that the O-ring material can seal again. Before long it worsens and needs to be replaced. My advice is to go back with a 90 durometer so it will resist extruding better. The factory size on my PP700S-A is an M1.5 x 5 but because of how it works, the exact size is not critical. I used a -008 to replace it...again, 90 durometer. That was 4 years and many fills ago.

Yep. My PP750 developed this leak only after a couple of months. This was exactly the problem. Replaced the o-ring with a Buna 90, still working fine.
 
  • Like
Reactions: Long_Gun_Dallas
I tend to take apart mine a lot, just fidgeting with the reg and such and happen to have the tube off of mine so i took a couple pictures. Wow incredibly simple design.

If you have not torn this airgun down before remove the black sleeve that covers the fill port. A simple oring is what holds it on. The pictures show with tube off of gun but assume it is on the gun and under pressure.

20230709_152509.jpg


20230709_141800.jpg

Unscrew the gauge until air starts to leak out. Once that stops leaking unscrew more to let out any remaining pressure. If you let this o-ring sit for a day or two they tend to shrink back to original size, and can be reused.
20230709_150214.jpg

Find a clean round rod slightly smaller than 7mm, a Phillips screwdriver would work better than a hex key as that has corners on it and can damage the fill port, insert in fill hole, hold tube a turn counter clockwise to lossen, then loosen the rest by hand. Once removed you can see on the bottom side of this assembly the valve and seal. Very simple as nervoustrig mentioned previously.
20230709_141805.jpg

Use a small screwdriver and remove. Notice it is not tight and there is no need for this to be so tight.
20230709_142009.jpg


20230709_142117.jpg


I pulled mine off and can see that there is a good bit of wear on the o-ring seal.

I just flipped mine over for now and put a little lube on it. Hopefully it will still work.

When reassembling everything there is nothing that needs to be more than finger tight as everything is sealed by o-rings. You will not be able to remove anything as soon as air pressure is applied. GL.




Allen
 
Last edited: