1994 Hitachi EX20UR-2 / EX30UR-2 / EX40UR-2 Excavator Workshop Manual (P/N KM-584E-00 / W584E-00)

This Hitachi workshop manual, publication KM-584E-00 / W584E-00, covers EX20UR-2, EX30UR-2 and EX40UR-2 excavators. The original publication carries a 1994 copyright.

The 388-page PDF is an image-based scan without a searchable text layer. Embedded bookmarks provide navigation through the manual.

• Hydraulic repair: Pump device and control valve disassembly and reassembly, including mechanical and pilot-operated spools, flow combiner valves and model-specific component layouts.

• Swing and travel drives: Swing motor and reduction gear overhaul, travel motor and brake valve service, bearing preload adjustment and component inspection limits.

• Undercarriage: Swing bearing and center joint removal and installation, center joint resealing, track adjuster and roller replacement, rubber track installation and track wear standards.

• Front attachment and cylinders: Front attachment removal, boom, arm, bucket and offset cylinder service, internal cylinder disassembly, seal replacement and reassembly checks.

• Engine repair: Cylinder head, valve, camshaft, piston, connecting rod and crankshaft inspection, with timing gear and chain assembly procedures and compression testing.

• Fuel system: Injection timing adjustment, nozzle spray and pressure testing, fuel bleeding, nozzle holder service and governor assembly references.

• Cooling and lubrication: Water pump disassembly and reassembly, thermostat inspection, oil pump clearance checks, and coolant and lubricating oil flow diagrams.

This manual is suited to mechanics experienced in hydraulic component overhaul and diesel engine repair, with access to lifting equipment, a press and the specified measuring tools.

Pump, Valve and Drive Repair

Model differences: Separate pump procedures distinguish the EX20UR-2 gear pump from the EX30UR-2 and EX40UR-2 plunger pumps with swash plates. Offset control is mechanical on the EX20UR-2 and pilot-operated on the other two models. These distinctions help match the repair procedure and component layout to the machine before disassembly.

Pilot and auxiliary valves: Front and offset pilot valve procedures explain spring identification, shim placement and cam clearance. Dedicated sections cover the EX40UR-2 shockless valve and the travel speed change solenoid valve.

Drive assemblies: Exploded and sectional views identify valve plates, needle bearings and planetary gear sets. EX30UR-2 travel device instructions include bearing preload adjustment using tool ST 3146.

Undercarriage and Front Attachment

Canopy and counterweight removal procedures cover access to the upperstructure. Swing bearing installation includes soft-zone orientation, while center joint repair distinguishes the EX20UR-2 sealing arrangement from the EX30UR-2/EX40UR-2 design.

Wear tables cover sprockets, front idlers, rollers, track link shoes, pins and bushings. Front attachment references extend to pivot joints, bucket points and side cutters.

Cylinder repair includes separate-type cylinder heads, cushion bearings, piston rods and model-specific tightening data. The assembly notes warn that an incorrectly seated cylinder head bushing can damage the U-ring.

Isuzu Engine Overhaul and Diagnosis

The engine section covers the 3KC1 for EX20UR-2/EX30UR-2 and 3KR2 for EX40UR-2. The 3KR2 specification table distinguishes swirl-chamber and direct-injection versions.

Internal repair covers cylinder bore and head inspection, valve-seat work, crankshaft bearing clearances and head-gasket selection. Timing references explain gear and chain alignment, including the 3KC1 tensioner ratchet reset.

Troubleshooting: Engine symptom charts address starting problems, unstable speed, low output, overheating, smoke, excessive oil or fuel consumption, and battery discharge. The diagnostic coverage centers on the engine and its supporting systems; excavator electrical wiring diagrams are not included.

Fuel service limits: Injection pump and starter faults can lead to specialist-shop referral. Governor adjustment requires an engine performance test, and the manual restricts governor disassembly when that test cannot be performed afterward.

The “Lubricating Oil Flow Diagram,” “Coolant Flow Diagram” and “Fuel Flow Diagram” support the component service sections. Listed test equipment includes compression gauge 5-8840-2008-0 and nozzle tester 5-8840-9016-0.

Fasteners and Hydraulic Connections

Model-specific torque tables, fluid data and wear limits accompany the repair procedures. Piping-joint connection views, O-ring seal drawings, split-flange illustrations and low-pressure-hose clamp views explain connection and sealing details.

Consult a qualified heavy equipment technician and review the manual's safety precautions before work on pressurized hydraulics or heavy structural assemblies.

File Format and Readability

Page count: The 388-page total comprises 355 pages of technical material, six contents pages, one index/copyright page, 23 blank separator pages, front and back covers totaling two pages, and a one-page Service Manual Revision Request Form.

Navigation and illustrations: There are 105 embedded PDF bookmarks covering sections, component groups and procedures. Small labels in the landscape control valve drawings and dense troubleshooting charts benefit from zooming.