1990– Hitachi EX120-2 Hydraulic Excavator Parts Catalog (P/N P12N-1-7)

Hitachi parts catalog P/N P12N-1-7 covers the 1990-onwards EX120-2 hydraulic excavator, including standard and Northern Europe configurations. Illustrated assembly breakdowns connect component callouts with part numbers, quantities, service codes, and applicable serial numbers for replacement-parts ordering.

Bookmarked PDF and Illustration Detail

Section access and drawing detail: Embedded PDF bookmarks open the foreword, contents, major parts sections, and numerical index. PDF text search is not available. Enlarging the electrical parts illustrations helps with densely grouped callouts; these drawings show component arrangements rather than electrical circuit diagrams.

One printable PDF contains 465 pages, including the cover, introductory material, section dividers, numerical parts index, nine blank separator pages, and two closing pages.

Hydraulic Assemblies, Running Gear, and Attachment Parts

The following selected catalog sections outline the main coverage. Additional listings include window-washer components and Japanese, English, and Finnish nameplates.

• Upperstructure: Illustrated parts breakdowns for the frame, counterweight, engine mounting, radiator, fuel system, oil tank, and oil-cooler piping.

• Hydraulic components: Pump device and swing-device listings, with main piping, pilot piping, control levers, and associated valves and fittings.

• Undercarriage: Exploded views and parts tables for the travel device, swing bearing, front idler, track adjuster, rollers, and center joint.

• Front-end attachments: Boom, arm, bucket, linkage, lubrication piping, and attachment-specific front piping, including short-arm and long-arm configurations.

• Rubber crawler parts: Separate track-frame, idler, adjuster, lower-roller, and rubber-crawler listings, alongside optional track-link configurations.

• Optional equipment: Air conditioning, clamshell equipment, one-point ripper, slope-finishing blade, and breaker/crusher piping arrangements.

Suited to mechanics and parts staff familiar with excavator assemblies, this catalog uses illustrated callouts and applicability tables rather than teaching repair procedures.

Component Breakdown and Identification

Exploded views show how individual items relate to larger assemblies. The Swing Device drawings separate reduction-gear components, while Travel Device listings distinguish complete assemblies, hydraulic motors, carriers, planetary gears, and related hardware.

The Front Idler and Center Joint sections provide further assembly-level identification. Drawing references lead to the corresponding parts tables, while the numerical index supports lookup when an existing part number is available.

Engine and Hydraulic Coverage Limits

The engine section identifies the complete engine, mounting hardware, filters, and selected associated components. Internal engine parts require the separately issued Isuzu 4BD1T parts catalog, as stated in the foreword.

The pump device is listed as a complete unit. Component illustrations support parts identification, but this catalog does not provide step-by-step overhaul instructions or hydraulic troubleshooting procedures.

Electrical and Optional Equipment Differences

Electrical parts tables identify wiring harnesses, relays, fuses, EC and PVC units, and switches. Separate standard and Northern Europe entries distinguish regional harnesses, gauge panels, and other electrical equipment.

Air-conditioner listings distinguish earlier and later assemblies, units, and controllers by machine serial number. Optional hydraulic pages also distinguish NPK breaker/crusher piping from OKADA/FURUKAWA arrangements.

Serial Applicability and Replacement Codes

Parts selection depends on both the page-level serial range and any narrower applicability beside an individual item. The catalog distinguishes machine serial numbers from equipment numbers prefixed H and front-attachment numbers prefixed F.

Interchangeability codes also matter: I identifies a one-way replacement, T identifies replacement parts used together as an assembly, and Y identifies mutually interchangeable parts. Treating every listed replacement as reversible can lead to an incorrect parts choice.

The service-code notes identify precision components requiring specialist repair. Mechanical repair and heavy equipment maintenance should be performed by qualified professionals using appropriate safety procedures.

Arm-Length Options: A Parts-Selection Preview

The attachment listings distinguish the 2.52 m standard arm, 2.1 m short arm, and 3.01 m long arm, with corresponding assembly and piping entries. These are catalog configuration sizes for identifying the appropriate attachment parts, rather than workshop adjustment values.