This manual covers the DOOSAN DAEWOO DX420LC HEAVY EXCAVATORS, specifically for serial numbers 5327 and up. These excavators are engineered for robust performance and reliability in demanding heavy-duty applications. Their design prioritizes durability and operational efficiency, making them a dependable choice for construction and industrial environments. The scope of this manual is comprehensive, providing essential technical service information, fitting instructions, and detailed repair procedures. It is designed to assist owners, technicians, and mechanics in maintaining the optimal condition and functionality of the DOOSAN DAEWOO DX420LC HEAVY EXCAVATORS. By following the guidelines within, users can ensure proper upkeep and address any necessary repairs effectively.