How to fix Seac Sub Asso 50 pneumatic leaking air

[mphelps]

I have a Seac Sub that just lost all pressure. When I try to pump it up I get a few pumps in and then you hear it leak out the front. I unscrewed the front piece, looked at everything and replaced the o-ring in the piece that moves up and down the cylinder, no change. Love the gun but living in South Dakota I don't have any places that work on it, so hoping its something simple I can fix myself. Spearing season is short here so hoping to get it going asap.
Thanks,

[popgun pete]

https://forums.deeperblue.com/thread...-inside.90024/

You need to read all of it if you take the rear handle off. To trace the source of the leak put the pressurised gun in a tub of water and watch where the bubbles stream out from. Then look for a damaged "O" ring and replace it.

The 50 cm is a short gun, so should be easy to work on. It will probably not have a power regulator as short guns don't need one.

[popgun pete]

There is also a new model of the Asso called the Asso UP, the guns are much the same in layout.

[popgun pete]

"O" ring kit here https://www.spearfishingworld.com/pr...un-o-ring-kit/

[popgun pete]

If air bubbles emerge from the muzzle area and you have replaced the piston "O" ring properly and that is not leaking then the next candidate is the muzzle "O" ring that sits on the inner barrel tube. It sits against a friction fit plastic collar so that it presses into the back of the nose cone, however if it gets pushed back slightly it may not seal. Air pressure then gets past the "O" ring and can come out of the join where the muzzle emerges from the nose cone or it can go along the screw threads in the muzzle and emerge from the inner barrel.

These air leak paths are shown on this sketch.

[popgun pete]

Let us know how you get on with fixing it. Work in a clean place, pneumatic guns opened up don't like dust or dirt getting inside them.