I make the polyurethane seals for these on my lathe (only for local friends). The old type Benjamin needs a special stripping tool for the valve unit. One thing to try before checking the seals is to cock the pistol before installing the CO2 cartridge. The spring holding the valve seal against the brass sealing ridge may be weak and the hammer spring may be holding it open. Only had one really difficult one to work on belonging to gingernut on here, was blowing gas down through the grips, had to turn up new complete valve made from his brass poker set on the fireplace !
Baz
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