The hydraulic circuit, including pumps and bearings, has important application in automotive industry. The hydraulic circuits inside the engine block are often affected by the cavitation phenomenon. Cavitation can cause pressure fluctuation inside the fluid circuit and considerably affect the engine workability, durability, and efficiency. This proposal will address the cavitation by modeling the oil flow in vane pumps and bearings and analyze the cavitation using 3D CFD software PumpLinx? (by Simerics Inc.) and 1D GT Suite.