The paper presents an analysis and validation method for a CAD model of a spur gear pumps series using FEM simulations. The analyzed pump is a new improved variant chosen among several constructive solutions created by parametric aided design in a range of gear pumps. Using mathematical computations and a calculus methodology there were identified the pressure values and forces generated in the pump assembly. The proposed study is especially applied to the gearing area and to the outlet chamber, where values and their variations are higher. FEM simulations are performed in these areas in order to identify and to present in a summary table the values of maximum stress, deformations and the percentages of calculation errors. The pump modelled and optimized by successive simulations led to the creation of an innovative gear pump series depending on the requirements imposed by the beneficiary.