Description

Fiat-hitachi EX300-2, EX300LC-2, EX300H-2, EX300LCH-2 Parts Catalog

If you’ve ever ordered a seal kit for a Fiat-hitachi EX300-2 and got the wrong size orion ring because some third-party website told you “this fits all”, you know the pain. That’s why this Parts Catalog exists – it’s the exact same reference the dealer’s parts counter uses. 89 pages of factory drawings, part numbers, and interchange codes. No guessing what goes where. The serial number range starts at 05001, so you can match your machine’s build date precisely. I’m Mike Callahan, and I’ve been wrenching on heavy equipment long enough to know that one wrong part number can cost you a full shift.

This isn’t a reprint of some generic aftermarket booklet. It’s the original Japanese/English bilingual catalog from Hitachi. The OCR excerpt on page 4 shows the foreword: it lists EX300-2, EX300LC-2, EX300H-2, and EX300LCH-2 hydraulic excavators. It covers the internal components of the hydraulic equipment – the PUMP, MOTOR, OIL sections, VALVE, CYLINDER, and a parts index at the back. Every part number ties back to an exploded diagram. You won’t find a “maybe fits” label here.

PUMP Section – What’s Broken Down

The PUMP chapter in the TOC is the first major group. It lists every gear, shaft, housing, and seal for the main hydraulic pump. Need the thrust plate or the regulator assembly? Page references are explicit. The catalog uses a symbol code system: W for field modification required, D for assembly-only replacement, K for service kit availability. This is the kind of detail that keeps a rebuild from turning into a scrap pile. I’ve seen guys order a pump cartridge based on machine model alone – only to find the spline count is different. This manual kills that risk.

MOTOR ; OIL – Understanding the Fluid Power Path

The MOTOR ; OIL section covers the travel and swing motors plus the oil cooler and filter circuit. The colon in “MOTOR ; OIL” means these are listed together because the motor group includes oil flow components. You get the part numbers for the swash plate, piston shoe, and valve plate. The catalog also shows service codes like S for service-only parts (not installed at factory) and OS/US for oversize/undersize components. If you’re refreshing a swing motor, you’ll appreciate knowing whether the piston ring set comes as a kit or individually. Page 5 explains the compatibility column – symbols I, P, T, Y tell you if a part is interchangeable. That’s factory data, not guesswork.

VALVE and CYLINDER – Where Hydraulic Force Meets Metal

The VALVE chapter lists every spool, spring, sleeve, and plug for the main control valve. The CYLINDER section covers boom, arm, and bucket cylinders – rod seals, piston rings, gland nuts. Each cylinder assembly is broken down to the individual O-ring. The part numbers are specific to the serial number range (05001 and up). The manual even tells you when a part was introduced – look for the “#” symbol on page 5, indicating a new addition. That’s critical if you’re trying to repair a machine that had a mid-year design change. Without this catalog, you might order a seal kit that was superseded three years ago.

3 Reasons to Choose OEM Documentation Over Aftermarket Copy

First, the compatibility codes. Aftermarket catalogs often skip the I, P, T, Y notations – meaning you can’t tell if parts are direct replacements or require a conversion kit. Second, the exploded diagrams are drawn to scale with reference numbers matching the parts list. Third, the OEM catalog includes the Japanese-English bilingual format, so if you ever have to cross-reference with a domestic supplier, you’ve got both names. That’s worth the price of admission alone. For a related manual, check the Hitachi EX300-2 EX300LC-2 EX300H-2 EX300LCH-2 Parts Catalog – same family, different model year.

I’ve also used the Fiat-hitachi 850-3, 850LC-3, 870H-3, 870LCH-3 Parts Catalog and the Fiat-hitachi ZX50U-2 Parts Catalog – 120 Pages of OEM Specs for smaller excavators. All genuine, all factory. If you want to understand how serious the automotive industry is about parts standardization, check Automotive Industry Overview.

Who Needs This 89-Page Catalog?

Home garage guys who rebuild their own excavator hydraulics. Shop owners who want to avoid tying up a bay waiting for the wrong part to arrive. Beginners who are scared of ordering the wrong seal kit and blowing $300. This catalog is for anyone who wants to match a part number to a physical component before they pull a credit card. The audience is DIY mechanics and equipment owners – you don’t need a degree, just the ability to read a parts list and turn a wrench safely.

Source Validity – Original OEM Print, Not a Scan of a Scan

The file name ends with “_Parts_Catalog_en-ja-27514003756.pdf”. That’s the internal Hitachi reference. The cover states “P15K-EI-2”. Everything from the serial number application to the “D” prefix for date changes (e.g., D93/01 meaning January 1993 onward) is preserved. Aftermarket documentation never includes that level of granularity. They reprint the illustration but omit the revision codes. That’s how you end up with a piston that is physically identical but has a different material coating. This manual tells you when the change happened.

FAQ

Does this cover both English and Japanese?

Yes.

How do I decode the compatibility symbols like I, P, T, Y shown on page 5 of the catalog?

Page 5 explains each symbol: I means you can use the alternative part in place of the original but not vice versa; P means the original is prohibited – you must use the alternative; T means a combination of parts from the alternative column is required for interchange; Y means unconditional interchange. The catalog also lists service codes like W (field work required), D (assembly-only), K (kit available). This is critical if you’re ordering parts for a machine with running changes. Ignoring the code can lead to buying a part that won’t physically fit because the mounting bracket was revised.

Access the Factory Manual – it’s the same reference we use in the shop to avoid wasting a customer’s money. You’ll get a searchable PDF with all 89 pages, every part number tied to an exploded view, and the confidence that you’re not stabbing in the dark. Automotive Industry Overview if you want background on why OEM data matters. Now stop ordering parts by eye and start using the real catalog.