I lightly sanded the radomizer tube and piston and for a while it worked great, now it is reverse only and the radomizer ball is staying on one tube only and not floating free. i noticed the center chamber o-ring is worn down to the metal and i assume it's letting some pressure stay in the chamber,not letting the ball releae. does anyone know if this o-ring can be purchased for replacement. i hate to replace the whole center chamber just to replace one o-ring that's probably 5 bucks or less... if you know of any way,,,, guidance appreciated!! thanks