Description

Fiat-hitachi 110, 125US, 110M, 135US, 120 Workshop Manual – OEM Factory Specs

If you’re digging into a Fiat-hitachi 110 or 125US and the manual you grabbed online says something like “tighten to snug,” walk away. That spec will cost you a hydraulic pump rebuild or worse. I’ve been an ASE Master Technician for 28 years, and I’ve seen what happens when guys trust aftermarket PDFs for torque values on these excavators. This is the real thing – factory-issued workshop manual, 748 pages, direct from Hitachi. No translation errors, no “general guidelines.”

748 Pages of Disassembly and Assembly Procedures

Every section you need to split the machine is laid out in plain sequence. Section 2 covers the upperstructure – the pump device, control valve, swing device, pilot valves, and the holding valve on the 135UR. I appreciate that the TOC lists separate subsections for “DISASSEMBLE PUMP DEVICE” and “ASSEMBLE PUMP DEVICE” because skipping steps on a variable-displacement pump creates cavitation issues you don’t want. The manual also includes the regulator and solenoid valve breakdown for the ZAXIS110, 110M, 120, 130, 130LCN, 125US, 135US. That level of model-specific detail is why you buy OEM.

Torque Specs – Where the Real Work Starts

Section 1 has a dedicated “TIGHTENING TORQUE SPECIFICATION” chapter with a torque chart for standard bolts and a separate table for piping joints. I’m not talking about generic ft-lb ranges – these are Hitachi’s numbers for every fastener on the machine. When you’re reassembling the swing motor or the travel device, you need that page. I’ve worked on Hitachi Zaxis excavators long enough to know that over-torquing the main frame bolts will crack the casting. Use the chart. Don’t guess.

Does This Manual Cover the 110M and 135US?

Yes – the TOC explicitly lists the 110M under painting, travel reduction gear disassembly, and the 135US under pilot valve removal and installation. The manual also includes the ZAXIS125US, 135US, and 135UR variants. If you own a 135UR, you get separate sections for the blade control valve, offset pilot valve, and emergency stop solenoid valve unit. That’s not something you find in a third-party compilation. The manual number printed on page 1 is KM-187E, and it’s the real volume W187E-03.

Avoid Aftermarket Guesswork

I won’t use aftermarket documentation for anything that moves under 2000 psi. This manual came from Hitachi Construction Machinery Co., Ltd. – that’s the manufacturer. The introduction on page 3 spells out the safety alert symbols and tells you that “CAUTION” means potential injury if you ignore it. A reprint shop doesn’t include that warning. If you value your fingers and your machine’s hydraulic system, you pay for the factory source. Related manuals worth having: the HITACHI ZAXIS Excavator Technical Troubleshooting Manual for electrical diagnostics, and the Fiat-hitachi ZX75US Workshop Manual – OEM Factory Service Specs if you’ve got the smaller machine in the fleet. For compact work, the Fiat-hitachi Zx40U Workshop Manual – OEM Factory Service Specs follows the same exacting standards.

Safety Warnings That Keep You Out of the ER

The manual uses a standard safety alert symbol next to heavy components like the counterweight and the swing bearing. It tells you to use appropriate lifting techniques and equipment. That’s not fluff – I’ve had a coworker drop a 500-pound swing device because he didn’t read the warning. The manual also includes periodic replacement intervals for hydraulic hoses and seals in Section 1. Those schedules are based on field data, not guesswork. For further background on how to handle heavy machine transmissions, see this Manual Transmission article from a reputable source. And for context on the broader construction equipment market, check the Automotive Industry Overview which includes heavy equipment trends.

Who Is This Manual For?

Home garage guys with a 110M or 125US in the back lot – you’ll be able to follow the remove-and-install procedures with basic hand tools and a cherry picker. Professional shop owners – you can hand this to your lead tech and know the torque values are correct. Beginners should read the “PRECAUTIONS FOR DISASSEMBLING AND ASSEMBLING” section before touching the pump. That section uses maintenance standard terminology to define wear limits. I recommend owning the companion HITACHI ZAXIS Excavator Technical Troubleshooting Manual if you plan to do any electrical work – the workshop manual alone won’t get you through a no-start condition.

Can I use this manual to rebuild the entire swing motor?

Yes. Section 2 under Swing Device has complete disassembly and assembly procedures for the swing motor and valve unit. Includes the maintenance standard with clearance and wear limits.

What if I need torque specs for the travel motor fasteners?

Those are listed in Section 1 under TIGHTENING TORQUE SPECIFICATION and the TORQUE CHART. The manual also includes a separate table for piping joint torque – critical for hydraulic lines on the travel device. You’ll find the travel device procedures in Section 3 with model-specific sub-sections for the 110, 110M, 120, 130, 130LCN, 125US, 135US, and 135UR. If you’re working on a ZAXIS110M, pay attention to the separate travel reduction gear and travel motor sections – they differ from the standard ZAXIS110. The torque chart applies across all models but always double-check the notes next to the fastener size. Some bolts on the travel motor require a specific angle after reaching initial torque – the factory manual marks those with an asterisk. I’ve seen techs ignore that and snap the bolt head off during the second pass. Don’t be that guy. The manual also lists the thread locker grade and lubricant type where applicable. For hydraulic fittings, the torque values are in ft-lbs and do not assume any lubrication on the threads – if the spec says 85 ft-lb, you run it dry unless noted otherwise. That’s the kind of detail that separates a repair that holds up for 5000 hours from one that drips oil at hour 50. And if you ever lose the paper copy, keep this PDF on your shop tablet – the page numbers match the hard copy exactly, so you can yell to your helper “check page 26” and he’ll find it.

I’ve trusted my own livelihood to factory manuals for decades. This one belongs on your bench – or your tablet – if you touch any of these machines. Access the Factory Manual and get the real numbers.