04894600 – TANK, HYDRO OVERFLOW 700 ML (OEM Ariens / Gravely)04894600 TANK, HYDRO OVERFLOW 700 ML (OEM Ariens Gravely) The 04894600 Hydro Overflow Tank (700 mL) is a genuine OEM Ariens Gravely reservoir used in the hydrostatic drive system on many Gravely commercial and residential units. This tank serves as the overflow expansion reservoir for the hydraulic (hydro) systemhelping manage fluid expansion, capture overflow, and support clean, consistent hydro operation. If your current tank is cracked, leaking,