Filling pcp

[toku58]

Here is the pics I was able to get

do I need different o rings like a different size

You think you can get pictures a bit more blurry? That would help. LMAO!!
You can try a bit larger O-rings. They do look a bit small? But with those pictures, who can really tell? 

 

[LTU-013]

Nothing wrong with your Hatsan, it does that if it's completely empty.

I had exactly the same problem, but only if tank is completely empty.

You have to put at least a bit of silicon on those o-rings or pump really fast or ask someone to press probe slightly, while you are pumping, or hold finger on the opposite side to seal

as soon as pressure will build up a bit it will seal and you'll have no problems to pump that up. It only happens when tank is completely empty.

Another way is to find anyone in your area, who has SCUBA tank, you just need that for the first time, I don't know exactly why it happens but in the future when tank has at least 50-100bar it will be no problem to refill. Somehow you just need to build a bit of pressure to seal probe for the first time, after that, it will work without any issues