Electrical fuel pumps play a key role in the automotive area, having the function to delivery fuel at proper pressure and flow rate to the injectors of internal combustion engines. In-tank centrifugal type of fuel pump, located submerged in the fuel tank, is currently the most widely used in the market. There is an increasing demand to control and minimize vibration levels experienced by fuel pump under operation that must comply with the requirements. Evaluation of the 8th harmonic order is critically important once its represents the vibration caused by the sliding contact among spring loaded carbon brushes and segments of commutator of electrical machine. In the present paper, a stochastic model in rotordynamics is developed considering uncertainties in the parameters that influence the dynamic responses of fuel pump system. The uncertainty analysis is conducted by applying Monte Carlo simulation method combined with the Latin Hypercube sampling. The obtained results show that the presented stochastic model is able to ascertain design parameters of fuel pumps reasonably. Ver menos