1990–1998 Hitachi EX220-2 / EX220LC-2 Excavator Service Manual (P/N T01-01–01)

This official technical publication (P/N: T01-01–01) details the 1990–1998 Hitachi EX220-2 and EX220LC-2 excavators, specifically covering the 15B-series build. With 616 pages of system schematics, hydraulic flow diagrams, and component overviews, the PDF manual delivers the precise engineering data required to understand the HINO H06CT-T engine and repair its associated hydraulic systems.

• Provides essential PDF repair data, advanced troubleshooting strategies, cross-section views, pilot piping schematics, hydraulic circuit diagrams, and input signal system charts.
• Explores critical assemblies including the swing dampener valves, travel reduction devices, shockless valves, wet multiple disc parking brakes, proportional solenoids, and nitrogen gas accumulators.

System Construction and Functional Walkthrough

Understanding core excavator subsystems directly speeds up diagnostics on the shop floor. This documentation breaks down the upperstructure layout, providing a clear look at the variable-displacement main pump (HPV091DW) and pilot gear pump assemblies. It explains the exact construction and operational logic of the main control valves, swing motor devices, and hydraulic pilot controls. Need to trace a fluid path? Detailed schematics map out the circuit flow for the arm regenerative valve, surge relief mechanisms, and the variable pressure compensated valve (VPCV) system used for load sensing.

Bypassing expensive dealer service calls becomes a reality with specific step-by-step procedures outlined in this guide, such as safely discharging the nitrogen gas accumulator, adjusting the auxiliary spool stroke speed, and verifying the DP-sensor differential pressure. A common diagnostic trap on the EX220-2 involves sluggish hydraulic performance being mistakenly diagnosed as a catastrophic main pump failure. In reality, the root cause is frequently a drifting DP-sensor output or a stuck shuttle valve failing to route the correct load-sensing signal to the pump valve controller (PVC). Furthermore, technicians often misinterpret a disabled swing dampener valve as a defect, not realizing it intentionally bypasses operation when hydraulic oil temperatures fall below 20°C (68°F).

Specification Highlights and Safety Data

Accurate capacities prevent costly errors during heavy shop maintenance. The text outlines critical volumes, including the 310-liter fuel tank and the 26-liter engine oil requirement for the HINO powerplant. Total hydraulic system capacity sits at 260 liters. You will also find reference values for system pressures, such as the 49 bar pilot pressure and specific swing dampener settings.

Working around high-pressure hydraulics requires absolute precision to avoid severe injury or equipment damage. Always verify the variable pressure settings for the DP-sensor and accumulator charging procedures directly against the specifications provided here before making any physical adjustments to the machine.

Beyond fluids and pressures, the documentation covers structural capabilities. For example, the maximum vertical wall digging depth for the 3.61 m arm configuration is accurately listed at 6,740 mm.