Abstract: Transportable system for the diagnosis, evaluation and prediction of leakages in hydraulic circuits of low pressure between 0 to 7 bar and of high pressure from 0 to 170 bar, quickly and safely for the operator is provided having a first independent circuit of high pressure and low flow and a second independent circuit of low pressure and high flow wherein the first independent circuit comprises: a first pressure subsystem, which delivers pressure to a first 4/3 valve with ports A, B, P and T, which is actuated by first solenoids, to deliver pressure to a first coupling A or to a first coupling B, in fluid communication with the ports A and B of the first 4/3 valve respectively a computer arranged to control the pressure of each pressure subsystem and associated method.