Hitachi EX135UR Excavator 1997 Service & Repair Manual

• Official OEM technical manual (Publication No. KM-191E, Vol. No. TO191-00) for the 1997 Hitachi EX135UR Cab Mounted excavator
• Covers operational principles, system logic, and component operation diagnostics across 949 pages
• Includes 36 detailed electrical system diagrams and 24 hydraulic circuit schematics documenting flow and control paths for complex troubleshooting and repair reference
• Documents 4BG1T Isuzu engine performance data alongside electrical sensor reference values
• Provides foundational logic for the electronic control and auto-MARCCINO systems
• Unit identification parameters covered: 2490 mm overall width and a 14000 kg operating weight

Operational Systems Documentation

This publication provides an in-depth look at core machine operating principles. It covers the electronic control system, breaking down engine management, Auto-Idle functionality, and Noise Reduction protocols. Hydraulics are mapped out extensively. The document details the circuit logic for main pump operation and control valve spool mapping. It also explains the integration of the blade circuit within the primary hydraulic system.

The front attachment control logic is fully documented. The auto-MARCCINO control unit manages movement restrictions, cabin collision prevention, and arm locus tracking. Every subsystem is described functionally. You see exactly how sensor inputs influence output signals for pumps and solenoid valve units, which is critical when analyzing systemic faults during a repair assessment. Always verify system pressure states and consult certified safety protocols before interacting with high-pressure hydraulics or live electrical systems.

Specification Highlights

Critical performance thresholds for the 62.5 kW Isuzu 4BG1T engine are thoroughly outlined. The manual provides exact baseline figures, such as the 18.1 MPa injection pressure and valve clearances set at 0.4 mm. Hydraulic data covers the HPV050FW-RH18D main pump, detailing a theoretical maximum flow of 95 L/min per pump section. System pressure limits are exact. The main relief pressure operates at 34.3 MPa, while overload relief settings reach up to 41.2 MPa for blade operations.