I have a big old splitter that I updated to a 28gpm haldex and atf. the piston has always leaked some but has gotten worse. Soooo I pulled the piston apart and the main components look o.k.,but I have a couple concerns. the original set-up was a single stage pump w/hydraulic fluid. the piston has chevron type seals. My question is can older pistons w/chevron type seals handle 2 stage pumps and atf ?? I would like to keep this set-up,but if piston design is outdated maybe I should punt.