Description

Hitachi Sumitomo 850-3, 850LC-3, 870H-3, 870LCH-3 Workshop Manual

I’ll tell you upfront: if you’re rebuilding a pump or swapping a swing motor on one of these Hitachi excavators, you don’t want some aftermarket PDF that skips the critical torque values. I’ve seen guys cross-thread a control valve spool because they used a generic chart. That’s why the Hitachi Sumitomo 850-3, 850LC-3, 870H-3, 870LCH-3 Workshop Manual is what I keep in my toolbox. This is the factory book—part number W1JB-E-00—554 pages of Hitachi’s own procedures.

Whatever model you’re wrenching on—standard 850-3, long-track 850LC-3, heavy-duty 870H-3, or long-track heavy 870LCH-3—the manual covers every variant. No guesswork about which regulator fits which pump. The table of contents splits the job into Section 1 General, Section 2 Upperstructure, and Section 3 Undercarriage. Each section goes deep.

Torque Specs from the Factory (Section 1 Tightening Torque)

The Tightening Torque section is where you live if you care about leaks and stripped threads. It gives the actual specification for piping joints, bolt grades, and periodic replacement parts. The torque chart breaks values by thread size and grade. For the main pump bolts or the swing bearing cap screws, you use those numbers. I don’t care how good you think your feel is—use the chart.

Does the Manual Cover the Pump System?

Section 2 Upperstructure includes the Pump Device subsection. That means remove and install procedures for the pump device, plus full disassembly and assembly of the main pump, main regulator, fan pump, fan regulator, pilot pump structure, and solenoid valve. Each step shows the order and orientation. For the main regulator, there’s a separate disassembly and assembly sequence. If you swap a regulator without the manual, you risk damaging the control piston bore.

You also get the Structure of Pilot Pump and Structure of Solenoid Valve diagrams. Those help when tracing hydraulic lines without a second tech on site.

554 Pages of Factory Procedures

That’s not a marketing number. The manual starts with Introduction and Safety, then goes through General precautions, painting, bleeding air from the hydraulic oil tank. Then Upperstructure takes over half the book: cab, counterweight, main frame, pump device, control valve (with 4-spool and 5-spool housing disassembly), swing device, pilot valve, solenoid valve, signal control valve, shockless valve, fan motor, fan valve, and engine removal and installation. Undercarriage covers swing bearing, travel device, center joint, track adjuster, front idler, upper and lower rollers.

Each subsection has a Maintenance Standard table. Those give wear limits and clearances. I use them to decide whether to rebuild or replace a travel motor.

Get the Right Torque Data Before You Start

Don’t skip the Tightening Torque chart. I’ve seen a swing bearing bolt loosen because someone used the value for a smaller bolt. The manual also lists periodic replacement parts—things like O-rings and seals that should be replaced on a schedule. Ignore those and you’ll be pulling the pump again in six months.

Control Valve: Factory Disassembly Procedure

The control valve subsection is split by spool count: 4-spool housing side, 5-spool housing side, plus upper/lower surfaces and front/rear surfaces. Each has its own disassembly and assembly procedure. You don’t mix up the shims or lose the springs. The manual also covers the housing itself. If you’re rebuilding a valve that’s stuck, this is the only reliable guide.

For related manuals, check the Hitachi Sumitomo SH330 SH330LC 350HD-3B 2006 Workshop Manual – Factory Specs. That one covers a different size class but uses the same format. Also see the Hitachi Sumitomo SCX1500-2, SCX1200-2 Workshop Manual for crane models. The Hitachi Sumitomo SCX1500-2, SCX1200-2 Workshop Manual – 506 Pages gives another heavy-equipment reference.

Understanding hydraulic circuits is different from a Manual Transmission setup. For a refresher on gear principles, read the Manual Transmission article on Wikipedia.

Who Needs This Manual?

If you’re a shop owner who has a tech swapping an upperstructure, or a DIYer rebuilding a travel motor in your home garage, this manual saves you from making expensive mistakes. The real-world use case: you’re replacing a swing motor. The Swing Device subsection gives you the removal and installation steps, plus disassembly and assembly of the swing motor and parking brake valve. You get the maintenance standard with wear limits. Without it, you risk misaligning the brake valve.

Source Validity: OEM vs Aftermarket

This is the original Hitachi Sumitomo Workshop Manual, not a scanned reprint from a third party. The part number W1JB-E-00 matches the factory document. The Safety section uses the official safety alert symbol and signal words. Every torque value, clearance, and procedure came from Hitachi’s engineering department. I don’t trust aftermarket documentation for these excavators because they often omit the Maintenance Standard tables. This book has them.

Does this manual cover the 850-3 without the LC suffix?

Yes. The 850-3 and 850LC-3 share the same workshop manual content.

What safety precautions are included?

The Safety section covers the safety alert symbol, signal words like CAUTION, and specific warnings for hydraulic pressure, heavy components, and lifting techniques. It also references the Operator’s Manual for operation safety. Always read the Safety section before starting any repair. The manual includes weight data for components to help you choose proper lifting equipment. I’ve seen techs skip this and drop a counterweight. Don’t be that guy.

Access the Factory Manual now and get the real Hitachi specs on your bench.