This paper investigates the stability of the Electro-Hydraulic Pressure Control System (EHPCS) by developing a more accurate model. A nonlinear mathematical model of the EHPCS is derived using impedance analysis. The coupling relationships between the pilot solenoid valve and the main valve are examined through linearization techniques. To assess the accuracy of the system model more precisely, the model of the pilot solenoid valve was independently validated through experiments. The pilot solenoid valve model demonstrated high accuracy and reduced errors in the system model. Comparison between simulation results and experimental data reveals a strong agreement, indicating that the system model effectively represents the system’s behavior and is suitable for stability analysis.