Which brand of second-hand excavator should I buy?

First look at what project you are working on, and then see if your personal funds allow it. Komatsu Carter's first-line brand is recognized by every major project and has good value preservation. Carter is strong, can do all kinds of projects, and the price is on the high side. Komatsu has stable performance and good preservation. Hitachi is fuel-efficient but likes oil leakage, which is called daily oil leakage on excavators. The speed of Kobelco is fast, and the earthwork is ok, but the river is not, and the walking strength can't keep up. Doosan is relatively cheaper. Every excavator has advantages. It's up to you. I am a second-hand excavator.