I have a 743 when I park it for a week the entire hydraulic reservoir empties itself out with no visible leaks under unit or anywhere inside. I suspect it's the drive motor carrier seals leaking into the chain case.. I just didn't think it would leak into the chain case from gravity? When I use the machine the level seems to stay up so I'm not exactly sure what is going on on here. Does anyone know if this unit has case drain filters? Anyone ever experienced this with the oil loss?