The aim of this paper is to document a better understanding of the performance of crankshaft mounted gerotor pump for IC engines lubrication. At different extents, the modeling, simulation and testing of a specific unit are all considered. BondGraph method is developed at the modeling and simulation phase to describe a mathematical approach of the geometry and kinematics flow ripple. However, more emphasis, at the testing phase and measurement techniques, is dedicated to obtain the flow ripple characteristic of this unit of gerotor pump through the secondary source method. Measurement techniques, at steady-state conditions, are required in order to enhance the BondGraph model and an improved comprehension of this type of volumetric pump.