1998–2003 Hitachi EX75UR-5 / EX75US-5 Hydraulic Excavator Technical & Workshop Manual Set (P/N TO197E-00)

This manual set covers the 1998–2003 Hitachi EX75UR-5 and EX75US-5 hydraulic excavators. It combines the Technical Manual (Operational Principle), TO197E-00; Technical Manual (Troubleshooting), TT197E-00; and Workshop Manual, W197E-00, including the Isuzu engine repair section.

• Hydraulic repair: Main-pump and pilot-pump disassembly, control-valve overhaul, relief-pressure testing, pump-flow measurement, and actuator drift checks.

• Electronic diagnosis: Dr.EX fault-code diagnosis and monitoring, symptom-based troubleshooting, electrical circuit testing, wiring diagrams, and connector views.

• Front controls: EX75UR-5 auto-MARCCINO diagnosis, angle-sensor initialization, depth-limit setup, and optional front-attachment and bucket configuration.

• Swing and travel: Motor and reduction-gear disassembly, parking-brake service, swing-bearing work, and center-joint repair.

• Engine and accessories: A-4JG1 engine teardown, internal inspection and reassembly, injection-nozzle service, and starter and alternator repair.

• Undercarriage and cylinders: Track-adjuster, idler, and roller overhaul, front-attachment removal, and hydraulic cylinder disassembly, seal replacement, and inspection limits.

Hitachi wrote these publications for experienced technicians maintaining and repairing the machine.

System Operation Walkthrough

This reference breaks down how the main controller (MC) regulates engine and hydraulic functions. It explains engine speed control, E-mode, auto-idle logic, travel-mode switching, and pump swash-angle regulation. Engine-learning procedures address work on the engine, engine control cable, EC motor, and MC.

For the EX75UR-5, the manual maps out the auto-MARCCINO front-control unit, boom/arm/offset angle sensors, and 9-unit solenoid valve. It distinguishes depth-limit control, cab-collision prevention, and arm oil-flow combining. Dr.EX service-mode coverage includes front-attachment codes and optional bucket dimensions used in collision-prevention setup.

Fault Tracing and Hydraulic Testing

The troubleshooting volume separates MC fault codes, operating symptoms without fault codes, monitor faults, and auto-MARCCINO faults. Its symptom-to-component charts help narrow a slow or inoperative function to electrical controls or hydraulic components before disassembly.

The Main Pump P-Q Diagram supports pump-flow evaluation. Component tests cover pilot and relief pressures, swing/travel motor drainage, and cylinder drift; specifications also identify pilot-pump flow and battery capacity.

The EX75UR-5 Hydraulic Circuit Diagram and EX75US-5 Electrical Circuit Diagram accompany cab/engine harness drawings and model-specific Connectors sheets. Electrical inspection covers continuity, voltage, current, and simulated-signal tests, with circuits for the monitor, relays, work lights, and heater. The EC motor test harness is identified as ST 7125, P/N 4274589.

Hydraulic Assemblies and Undercarriage Repair

Workshop procedures cover pump plunger/shoe and valve-plate inspection, swing-gear bearing preload, travel brake valves, and center-joint seals. Track service extends to adjusters, idlers, rollers, and master-pin removal, with component wear limits.

Swing-drive reassembly can deform the oil seal if the housing plug remains fitted during shaft installation. Cylinder assembly notes warn that a misaligned piston rod can damage the piston rings.

Before opening hydraulic components, mechanics must release residual pressure to prevent fluid-injection injuries.

Engine Repair and Fuel-System Limits

Internal engine procedures cover cylinder liners, valve guides, crankshaft bearing selection, timing gears, and reassembly. Lubricating Oil Flow and Coolant Flow diagrams accompany oil-pump, oil-cooler, and thermostat sections. Repair standards distinguish assembly dimensions from wear limits.

The injection-pump calibration sheets are examples; the manual assigns pump adjustment and repair to authorized Bosch/Zexel service outlets. The engine chapter includes several starter and alternator versions, with application-dependent timing and accessory specifications.

A Sample of Engine Settings and Pump Inspection Limits

These engine settings and pump inspection data are a small selection of the specifications in the set.

For the installed engine, the excavator troubleshooting volume specifies injection timing at 13° BTDC and cold intake and exhaust valve clearances of 0.4 mm. The thermostat specification gives an initial opening temperature of 82 °C at atmospheric pressure.

The main-pump maintenance standard limits clearance between the plunger outside diameter and cylinder-block bore to 0.060 mm, providing an inspection reference during pump repair.

Searchable Sections, Bookmarks, and PDF Contents

Search, navigation, and drawing detail: Most technical and workshop text is searchable; the final engine chapter and some hydraulic-diagram labels have no searchable text layer. Embedded bookmarks cover all three publications and the engine sections, although some links lead to incorrect pages. Small wiring, connector, and hydraulic-diagram labels require zooming.

The set is supplied as one printable, 987-page PDF, divided as follows:

These totals already include three publication title pages, ten diagram/harness/connector sheets in the troubleshooting volume, and 73 blank or note pages. The 220-page engine section is included in the workshop total.