Description

Fiat-hitachi EX120-3 Parts Catalog – 132 Pages of Factory Part Numbers

If you’re trying to rebuild a hydraulic pump on an EX120-3 without the factory parts breakdown, you’re wasting time and money. I’ve seen guys order five different part numbers because they used a third-party list that had the wrong supersession. This Fiat-hitachi EX120-3 Parts Catalog is the original Hitachi factory publication – 132 pages of exact part numbers, exploded views, and service codes. No guessing, no cross-referencing bad data. Get the right part the first time.

This catalog comes from Hitachi’s own engineering department. Every exploded diagram matches the production line. Every part number has been verified against the machine’s serial number range. Aftermarket reprints often skip the service codes – the little letters that tell you if a part must be replaced as an assembly (D) or comes in a kit (K). That detail saves you from ordering pieces that cannot be swapped individually. Page 1 shows the machine model and serial number prefix. Page 3 gives you the exact engine and machine manufacturing numbers to confirm compatibility.

Why You Need the Factory Parts Catalog

Working on construction equipment without a factory parts catalog is like rebuilding a transmission using only a hammer. The EX120-3 has multiple pump configurations – SINGLE, UNIT, and GEAR pumps, plus an ANGLE sensor. Each uses different part numbers. The OEM catalog breaks down every subassembly so you can order exactly what you need. No need to buy a whole pump when only the gear section is worn. That’s the difference between a $50 seal and a $2,000 assembly.

Fiat-hitachi EX120-3 Parts Catalog: Pump, Motor, Valve, and Cylinder Sections

The contents are organized logically. Start with the PUMP section – it covers the main hydraulic pump, including the SINGLE and UNIT versions, the ANGLE sensor, and the GEAR pump. Then the MOTOR;OIL section lists the TRAVEL motor, the SWING motor, and critically, the VALVE; BRAKE and VALVE; RELIEF on those motors. The rotary group, shaft, and cover parts are detailed with individual part numbers. Next, the massive VALVE section – eight subsections for the CONTROL valve alone (1/8 through 8/8), plus PILOT valves, SOLENOID valve, FC valve, multiple SHUTTLE valves, LOCK valve, four HOLDING valves, a ROTARY valve, and a general VALVE category. CYLINDER covers BOOM (right and left), ARM, BUCKET, and CLAMSHELL. ETC. includes the DP sensor. Finally, the PARTS INDEX lists every part number in numeric order. For larger machines, see the Fiat-hitachi ZX500LC, ZX500LCH Parts Catalog – 464 Pages.

4 Service Codes That Save You from Ordering Wrong Parts

Each part in this catalog has a service code column. Pay attention to these: W means field modification required – contact Hitachi before ordering. D means the part cannot be replaced separately; you must buy the whole assembly. K indicates the part is included in a service kit. R shows quantity varies per machine. S parts are service-only, not factory installed. OP is optional equipment. OS and US denote oversize and undersize components. A # symbol marks new entries. Memorize these codes. They are printed on every page of the parts list. Ignoring them is how you end up with a box of wrong parts.

Brake Valve and Relief Valve: Common Failure Points

Travel motors take a beating. The VALVE; BRAKE subsection within MOTOR;OIL (TRAVEL) lists every seal, spring, and spool for the parking brake valve. If your machine creeps on a slope, that valve is the first place to look. The RELIEF valve sections – both in the travel motor and swing motor – protect the hydraulic system from overpressure. Ordering the wrong relief valve can cause either sluggish operation or blown seals. This catalog gives you the exact Hitachi part number, not a generic replacement. Cross-check with the Fiat-hitachi 850-3, 850LC-3, 870H-3, 870LCH-3 Parts Catalog if you work on larger models.

Order Parts Using the Parts Index – Step by Step

Write down your machine serial number – it’s on the main frame plate. Find the section that matches the assembly you need. Identify the symbol number from the exploded diagram. Look up that symbol in the parts list on the same page. Note the part number and service code. Then verify it in the PARTS INDEX at the back. Call your Hitachi dealer with the part number, machine model, and serial number. That’s it. No guessing, no returns. Page 1 confirms your machine series; page 3 has the engine and serial number table. Use them.

Who Needs This Manual?

If you own or maintain a Fiat-hitachi EX120-3 excavator, you need this. Whether you’re a one-machine owner doing your own repairs or a shop that services a fleet, having the correct part numbers eliminates the back-and-forth with parts counter guys. Beginners should use it alongside a service manual – this catalog does not show torque specs or disassembly steps. But for ordering parts, it’s the only source that guarantees accuracy. The Automotive Industry Overview may give you background, but this catalog gives you results.

Why Trust Hitachi’s Own Documentation?

Hitachi Construction Machinery produces these catalogs for their dealers. The content comes from the same database that builds the machines. Every part number, every subassembly, every service code – it’s all verified against production records. Third-party editors copying the data inevitably introduce typos, shifted columns, and missing supersessions. I’ve compared aftermarket reprints against this original PDF. They miss the “D” code on critical brake valves, leading to orders that fail. This is the real deal, direct from Hitachi. For reference on industry standards, see Automotive Industry Overview. Also check the Fiat-hitachi ZX50U-2 Parts Catalog – 120 Pages of OEM Specs for smaller excavators.

Frequently Asked Questions

Does this catalog include torque specifications for assembly?

No, this is a parts catalog, not a service manual.

How do I find the correct part number for a control valve spool?

Use the VALVE section which is split into eight sub-sections (1/8 through 8/8). Each sub-section covers a specific part of the control valve assembly. Find the exploded view that matches your machine’s configuration, note the symbol number, then cross-reference with the parts list on the same page. The parts index at the end of the manual lists all part numbers in numerical order, so you can verify. Pay attention to service codes like D (assembly-only replacement) or K (kit) to ensure you order the right component. This catalog is the only reliable source for genuine Hitachi part numbers.

Access the Factory Manual and start ordering parts like you’ve done it a thousand times. No more returns, no more downtime waiting for the wrong seal. This is the part book that keeps your EX120-3 running.