Fluid Transfer unit suitable for filling, recirculation - via onboard 80l reservoir - and emptying of filtered hydraulic fluids and lubrication tanks. The FTU can be utilised either as additional filtration to a system with a high incidence of contamination, or can be used as a standalone recirculating filtration circuit to clean fluid to a predetermined contamination level - monitored by the onboard ICM - prior to transfer of fluid to the system.