I use Bar Leak jack oil on all my hydraulic jacks. I bleed them from day one then I install Bar Leak. It keeps the seals in good shape and less prone to leaking

1200CC BIG BORE, W/WISECO PISTONS,.250 STROKED CRANK, PORTED/POLISHED HEADS AND LARGER VALVES, CUSTOM WELDED EXHUAST, DUAL 42MM MIKUNI CARBS.