I posted a want to buy add on the classified’s here several weeks ago for a 22 caliber HW 90. Fishing 43 responded that he had a HW 90 that would not hold air. He was very frustrated and just wanted to get rid of it. He tried everything he could to get it to hold air. The price was right, so I bought it thinking I’d give it a shot. Tried new o-rings, new Schrader valve courtesy of another kind member on this forum, scax, whom I will buy lunch one day. The dummy piston had a couple of flaws on it that I could feel with my fingernails, so I hand polished it to a shiny luster. To no avail, it still leaked very bad. It would leak down entirely in about 10 minutes you could hear the air rushing out of it. Finally, I took the ram out of the gun and placed in a bar clamp so I could get to the fill port, and pressurized it. A little soapy water revealed a very small hole in the main piston, in the slot were the cocking shoe runs. I have a buddy who is a genius with a TIG welder. He put a bead on the hole. I filed it down and smoothed up the cocking shoe slot. The weld also penetrated to the inside of the piston. I took a wooden dowel and some sandpaper and smoothed it up.
So far so good I pumped it up to about 24 bar. Shot it for about a half hour rechecked the pressure and it was the same. Very happy with this journey. Look forward to put ting the HW 90 through its paces.
So far so good I pumped it up to about 24 bar. Shot it for about a half hour rechecked the pressure and it was the same. Very happy with this journey. Look forward to put ting the HW 90 through its paces.
