Product Features -Fleck 2510 Softener Rebuild Kit. Rebuild kit for the Fleck 2510 softener valve. Kit includes piston assembly, seal & spacer kit, and the brine valve (Fleck part# 61670-00 and 60011). Piston part number is 60090 and seals and spacers are 60121. These are genuine Fleck parts, not generic replacements.