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.

[mphelps]

Originally Posted by 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.

Thank you for all the info. How does the back handle come off? Just unscrew it somehow?

[mphelps]

My gun has a yellow handle but it does have a power regulator on it. If I get some air to stay in the gun, I assume I need to release all of it before taking it apart?
Are there any video's out there somewhere on how to take this thing apart? I find it easier if I can watch someone do it instead of trying to just read how to do it.

[popgun pete]

Originally Posted by mphelps

My gun has a yellow handle but it does have a power regulator on it. If I get some air to stay in the gun, I assume I need to release all of it before taking it apart?
Are there any video's out there somewhere on how to take this thing apart? I find it easier if I can watch someone do it instead of trying to just read how to do it.

Don't take it all apart if you don’t really need to. All the instructions are in that thread I referenced at the start, you just need to keep reading beyond where other people chimed in.
https://forums.deeperblue.com/thread...-inside.90024/ post #8 and onwards from there.

A lot of guns get damaged when they don't need to through people overdoing it. If you know your way around a pneumatic it is relatively simple, but bust some parts and they will be hard to replace unless you buy an entire assembly.

[popgun pete]

If your gun has a yellow grip then it must be an Asso Up, the original guns have black handles which are one single moulding. The Asso Up is basically a styling revamp. A copy of the Asso original is the Hang Fung Industrial pneumatic made in China, these have appeared as colored grip guns and the grip color has changed depending on the batch they made and who the guns were sold through using different brand names. I recall seeing a yellow grip on a Hang Fung gun being reviewed, poorly as it turned out.

Aqua Gear is the Hang Fung brand name, but if a retailer wants to place a big order then they will change the mould plates to reflect the company name provided the quantity justifies making the change.

[mphelps]

I had a Balco speargun many years ago I tried to fix and ended up screwing that one up to I'm hesitant to tear into this one. I've had it for 10 years, but living in South Dakota it doesn't get a lot of use - a few dives a year. I was able to get it to hold some air yesterday and took it diving and shot a walleye so maybe I might get a little life out of it yet and can find someone to overhaul it this winter.

[popgun pete]

I could have fixed your gun in the time it took me to write the first post. Let all air out, push piston back, use Philips head screwdriver blade inserted through opposing muzzle relief ports, hold gun between knees, screw muzzle off using screwdriver as wrench. Twist nose cone and pull out of tank, remove muzzle “O” ring from inner barrel, grease screw threads, put new “O” ring on, and replace parts in reverse order. On a small gun it is very simple.

[mphelps]

Pete, thanks for the replies.
I was incorrect, my gun has a black handle like you pictured earlier.
For the o-ring you are talking about replacing, is that #35 from the parts diagram you posted or one of the other ones?

[popgun pete]

It is part number 6, the nose barrel "O" ring.