Servo valves are unnecessary in electro-hydrostatic actuators (EHAs) because they are directly controlled by servo-motors. Owing to the above characteristics, the control frequency and power efficiency improve, and the size of a hydraulic system reduces. However, oil leakage and static friction tend to be significant in EHAs. In addition, the nonlinear characteristics of oil leakage make compensation difficult. In this study, we propose an EHA model that reflects oil leakage and static friction. To eliminate the necessity for complicated leak identification, oil leakage is estimated using two encoders. Then, the effect of static friction is suppressed using feedback modulators (FMs). Finally, disturbance observers (DOBs) are integrated into the model to eliminate disturbances in the EHAs and the validity of the proposed method is verified experimentally.