Description

Fiat-hitachi EX300 Parts Catalog

You are rebuilding the swing drive on an EX300 and the old seal has no number stamped on it. You order three “universal” seals from different suppliers, none match the groove, and the machine sits another week. I have seen that exact situation burn a week of billable time and a thousand dollars in freight. Stop guessing. The only way to get the right part is the factory parts catalog – not a scanned copy someone ran through OCR and slapped a watermark on. This is the original Fiat-hitachi print, 465 pages, OEM source.

UPPERSTRUCTURE: Where the Hydraulics Live

The upperstructure section covers the cab, counterweight, swing machinery, hydraulic pumps, control valves, and everything mounted on the turntable. Each component is illustrated with an exploded diagram. The part number, description, quantity per machine, and service codes are listed in a table next to the drawing. On page 4, the manual explains the model code system – EX300-3C, EX300LC-3C, EX310H-3C, EX310LCH-3C – so you know exactly which machine your parts apply to. No cross-referencing random websites.

UNDERCARRIAGE: Track Frames and Final Drives

Undercarriage parts – track chains, sprockets, idlers, rollers, final drive assemblies – are the ones that wear out fastest on a job site. This catalog gives you the factory part numbers for standard and LC models. You will find the track adjuster seal, the sprocket segments, and even the bolts that hold the final drive to the frame. Service codes like “W” (field modification required) and “H” (precision part – do not disassemble) are listed next to each item. Those codes are defined on page 5. Read them before you order anything.

FRONT-END ATTACHMENTS: Boom, Arm, Bucket Linkages

The front-end attachments section covers boom, arm, bucket linkage pins, bushings, and hydraulic cylinders. If you need the pin for the bucket linkage or the seal kit for the arm cylinder, you will find it here. The manual lists each part with its own item number on the diagram. Pay attention to the “Applicable Machine No.” column – there are serial number breaks. Order the wrong one and the bushing will be a few millimeters off. I have seen that happen.

BREAKER & CRUSHER PARTS: Adding Hydraulic Hammer Parts

This catalog includes a dedicated section for breaker and crusher parts – the mount brackets, hoses, and control valves needed to run a hydraulic hammer or a crusher attachment. If your EX300 has a secondary attachment, you need the factory brackets to avoid cracking the boom. The section lists OEM part numbers for the entire system. Do not trust aftermarket weld-on plates unless you want a cracked boom within a year.

465 Pages of Part Numbers – How to Use This Catalog

The catalog contains 465 pages of part listings, diagrams, and a full parts index at the back. The index lists every part number in numerical order with the page number where it appears. Use that index to find a part quickly. The manual also includes service codes: “D” means replace the assembly, not the single part; “K” means the part is available in the service market; “OP” means optional – not standard. You need the machine serial number handy because every part has a serial range. The manual even shows design change dates (e.g., D96/03 for March 1996). Do not guess.

Does This Catalog Cover Engine Parts?

No. The engine – Isuzu A-6SD1TQA – is in a separate parts catalog. This manual references it on page 4. If you need pistons, rings, or engine gaskets, get the engine-specific catalog.

Source Validity: OEM vs. Aftermarket

I have been burned by aftermarket parts catalogs that claimed “compatible” but had the wrong bracket hole spacing. This is the original Hitachi factory publication printed for Fiat-hitachi joint models. It is not a third-party compilation. The part numbers are verified against Hitachi’s own database. The diagrams are scanned from the original printing. If you want to keep your machine running without chasing ghost part numbers, this is the only source you should trust. For a companion repair manual, see HITACHI EX300 Series Excavator Parts Catalog and HITACHI EX300 Series Parts Catalog. For the step-by-step service procedures, get the Hitachi EX300 Series Technical Manual Introduction. If you are new to heavy equipment documentation, the Automotive Industry Overview may help you understand the terminology. Also check Automotive Industry Overview for context on standards.

FAQ

Does this parts catalog include engine components?

No, the engine parts are in a separate Isuzu diesel engine catalog.

How do I find the part number for a specific component?

Use the Parts Index at the back. Each part number is listed numerically with page references. The manual uses a structured system: the item number on the diagram, the factory part number, the description, the quantity per machine, and service codes. Make sure you have the machine serial number handy because some parts have serial number breaks. The ‘Applicable Machine No.’ column tells you which serial range uses that part. If you see a ‘D’ code with a date (e.g., D96/03), that indicates a design change after March 1996. Always verify the serial number on your machine.

Do not waste time hunting for parts that might fit. Get the factory catalog and order the exact piece the first time. Access the Factory Manual and keep it on your tablet in the cab – it will save you more in wrong parts than the cost of the PDF.