At one time I saw a filter kit to install on return side of rear wheel assist. Filters return oil in case of motor failure to prevent contamination of the rest of the hydraulic system. Does anyone know who is/was making it? I have searched with no success. Only thing I found is this. Suction Filtration Kit 60 & 70 Series – Herrs Machine Hydrostatics (herrshydro.com)  Not sure if this is it or not. Anyone put this filter system on? Thanks