This study involves the operation of the Common Rail Diesel Injection, atomization characteristics of fuel and reconditioning of diesel engine nozzles. The nozzles of the Common Rail system were repaired in order to give them optimum conditions of operation. For it be confirmed, the volume of Diesel injected was measured as a function of injection pressure, injection angle and the cone angle of the atomized fuel into new nozzles (control), used and reconditioned. In the evaluation of the volume, it was used a circuit consisting of a high pressure pump, a source of pulses and a reservoir of fuel oil. For the geometric characteristics of the fuel spray was used a high speed filming, 4000 frames per second, applying shadowgraphy techniques for measuring these angles. The experimental results allowed evaluating the types of changes in the nozzle after the reconditioning process. It was observed that the reconditioning process of nozzles does not modify the operation of the nozzle or diesel engine. There are no losses in the combustion of fuel and no change in performance, consumption of fuel, efficiency and emissions of the vehicle.