The Caterpillar 320c is a legendary medium-sized excavator, and its price is heavily dictated by its mechanical health. You must verify the Cat 3066 T engine performance, ensuring there are no signs of excessive blow-by or black smoke. Check the hydraulic pump pressure (standard is approximately 34.3 MPa) and look for leaks in the main control valve. The undercarriage condition (track links, rollers, and idlers) accounts for nearly 20% of the machine's value, so ensure the wear life remaining is clearly documented.