Description

Hitachi Sumitomo SCX900-2 Technical Manual – Factory Specs for the Hydraulic Crawler Crane

You’ve got a 90-ton hydraulic crawler crane sitting in your yard or on a jobsite, and you need specs that match what Hitachi Sumitomo stamped on the turntable bearing. Aftermarket PDFs that claim to cover the SCX900-2 but skip the EPC controller details or give you generic axial-piston pump data? That’s a recipe for blown seals and lost billable hours. This 24-page Hitachi Sumitomo SCX900-2 Technical Manual is the OEM file – the same one the factory techs used when assembling the upper revolving frame in Japan. No reprints, no guesswork.

Control System: EPC Controller Mode I and Mode II

Page 2 lays out the two control modes for the EPC controller. Mode I varies engine speed and pump discharge together by twisting the grip – that’s your precision crane work, like picking a load in a tight spot. Mode II locks engine rpm at full throttle and lets you adjust pump flow alone, which is what you want for clamshell duty-cycle operations. If you try to guess which mode is active without the manual, you’ll stall the engine or overwork the hydraulic pumps. Documented right there: quadruplicate and triplicate tandem valves actuated by remote-controlled hydraulic servo. The manual even calls out the specially tailored pressure compensating valve for minute drum control.

Hydraulic System Components – Three Variable Displacement Pumps

Three variable displacement axial piston pumps drive the main, aux, boom hoist, and optional third drum. The manual spells out the pump control system in the same section – page 2 also covers the fixed displacement duplicate tandem gear pump for system valve and cylinder controls. You get the flow path from the pump discharge to the motors, including the counterbalance valves on the hoist motors. If you’re swapping a pump or troubleshooting low flow, you need this diagram. For reference on how old-school manual transmissions work, check the Manual Transmission article – the contrast between gear drives and hydrostatic systems is useful background.

Turntable Bearing and Frame Construction – What’s on Page 2

The upper revolving frame is all-welded, precision machined, and bolted to the turntable bearing. The manual describes the inner race with internal slewing gear bolted to the lower frame, outer race bolted to the upper frame – single shear ball type. If you’re replacing the bearing or checking for wear, the manual gives you the mounting surface spec. Page 2 also mentions the machined surface for the load hoist, optional third drum, and boom hoist assemblies. Don’t assume the bolt pattern is standard – verify against the factory drawing.

Boom Hoist and Travel Motors – Factory Brake Specifications

Page 3 covers the boom hoist motor: axial piston with counterbalance valve and a spring-applied/power-released multiple wet-disc brake. The travel motors are shoe-in design, variable displacement axial piston, also with brake valves. The manual notes the slew motors are two axial piston units with the same brake type. If you’re rebuilding a motor, you need the brake release pressure and the counterbalance valve setting – those numbers aren’t in any aftermarket handbook. For a deeper dive into how power is transmitted from engine to tracks, read about Manual Transmission principles – the mechanical to hydraulic conversion is key.

Who Needs This Manual – and Why

If you own, operate, or maintain a Hitachi Sumitomo SCX900-2, this 24-page technical manual is your on-site reference. It’s not a repair guide – it’s the specifications document that tells you what pumps, motors, bearings, and control valves were factory-installed. When ordering a new third drum motor, you’ll reference the variable displacement axial piston motor description on page 3. When troubleshooting an EPC controller fault, you’ll check Mode I vs Mode II on page 2. Beginners? This isn’t a how-to-crane-101 book. But if you’re a home garage enthusiast tackling a refurb on an old SCX900-2, you need these specs to avoid mismatching parts.

Source Validity – OEM File, Not Aftermarket Copy

This is the original factory PDF, file name HITACHISUMITOMO_SCX900-2_Technical_Manual_en-31113003823.pdf. No third-party editing, no missing pages, no reprints. The OCR text on page 1 shows the “Specifications – ASIAN ISSUE” header and HSC PAH code. Compare that to an aftermarket manual that might list generic torque values for “crane” – the Hitachi Sumitomo OEM manual gives you the actual frame/welding description and pump model numbers. If you’re serious about keeping your equipment in spec, you don’t guess. You access the factory manual.

Related Manuals You Might Need

• Hitachi Sumitomo 330LC, 350H, 350LCH, 370MTH, ZX330 Technical Manual
• Hitachi Sumitomo SH200-3 SH220-3 Technical Manual 166 Pages
• Hitachi Sumitomo SH240-5 Technical Manual – Factory OEM Specs

Is this manual a full repair manual or just specifications?

It’s a specifications document – 24 pages covering superstructure, control system, hydraulic pumps/motors, and frame construction. Not a step-by-step rebuild guide.

Does it include wiring diagrams?

No electrical schematics. The manual focuses on hydraulic and mechanical components – pumps, motors, control valves, and turntable bearing. Page 2 describes the hydraulic servo control system but not wire colors.

Can I use this for other Hitachi Sumitomo models like the SCX800 or SCX1000?

No. This manual is model-specific to the SCX900-2. The control system, pump configuration, and frame dimensions differ across models. Order the correct manual for your serial number.

How many pages and is it the original OEM version?

24 pages, direct from the Hitachi Sumitomo factory PDF. Not a reprint or scanned copy – you get the original digital file with page numbering and official headers.

You’ve got the specifications memorized? Good. But if you want to confirm the pump type, check the engine-pump control modes, or verify the turntable bearing construction, you need the factory document on your screen. Stop trusting memory and third-party summaries. Access the Factory Manual now and keep it in your service binder.