Description

Komatsu PC128UU-1, PC128US-1 2000 Service Manual – OEM Shop Manual

You’ve got a **Komatsu PC128UU-1, PC128US-1 2000 Service Manual** on your bench? Good. Because without it, you’re working blind. I’ve been an ASE Master Technician for 28 years, and I can tell you: aftermarket copies get torque specs wrong, skip steps, and leave out critical safety procedures. This is the real factory document – 794 pages of what Komatsu engineers intended.

01 GENERAL – Specifications and Lubricants for Your Komatsu

Get the fluid specs right. Page 01-1 lists the weight table and approved lubricants, including hydraulic oil, engine oil, and gear lube. Use the wrong viscosity and you’ll cook the hydraulics. This section also has the general assembly drawing – critical for identifying part locations before you tear anything down.

10 STRUCTURE AND FUNCTION – Hydraulic Circuit Diagrams and Valve Control

This section alone is worth the price. It includes the actual hydraulic piping drawing, full circuit diagram, and detailed breakdowns of the CLSS, swing motor, travel motor, PPC valve, EPC solenoid valve, and boom holding valve. Need to understand the valve control mechanism? Section 10 explains it with OEM drawings. The electronic circuit diagram and machine monitoring system are here too – a lifesaver when the dash lights start flashing.

What’s Inside the Testing and Adjusting Section?

Section 20 is where you spend most of your time. Standard value tables for engine, chassis, and electrical parts – these give you the factory tolerances for measuring wear. Valve clearance adjustment procedure with exact specs. Blow-by pressure measurement, fuel injection timing, and hydraulic pressure tests for work equipment, swing, and travel circuits. Page 20-1 starts this section. If you skip the pressure release procedure before cracking a line, you’re asking for a face full of hot oil. Don’t do it.

Get the Right Torque Data – Standard Value Tables

Torque specs are not suggestions. The standard value tables in this manual list every fastener torque from the engine mount bolts to the track shoe nuts. I’ve seen guys strip threads because they used a generic chart. These are Komatsu’s own numbers. Also included: the standard value table for electrical related parts (separate from the automatic horizontal digging machine). If you’re rebuilding the swing motor or travel motor, you’ll find the clearance specs in the maintenance standard section.

OEM vs Aftermarket: Why Factory Specs Matter

I’ve had techs bring me aftermarket copies where the torque specs were off by 10 ft-lbs. That’s a blown head gasket or a snapped bolt waiting to happen. This manual is an original 2000 Komatsu publication. The electrical circuit diagrams are crisp, the troubleshooting charts follow the factory logic. When I rebuilt a swing motor on a PC128US-1 last year, the aftermarket manual I found online had the wrong snap ring dimensions. That cost me an extra hour of rework. The OEM manual had it spot on. That’s why I only recommend factory documents.

Audience Fit – Who Needs This 794-Page Manual

If you own a PC128UU-1 (serial 2347 and up) or PC128US-1 (1715 and up), you need this. DIY owners who do their own track tension adjustments, hydraulic repairs, or engine work will find everything laid out. Professionals will appreciate the standard value tables for measuring wear. The manual covers everything from the radiator and oil cooler to the electronic control system and machine monitoring system. The engine is the S4D102E-1 – for deeper engine details, the manual references the separate 102 Series Engine Shop Manual.

For a refresher on how a manual transmission functions, see Manual Transmission on Wikipedia. The track frame and idler cushion sections require a solid understanding of mechanical fundamentals – Manual Transmission is also a good primer.

If you need other Komatsu service documentation, check out Demag Komatsu H 285 S Service Manual – 544 Pages of Factory Specs, Komatsu WA430-6 Service Manual – 306-Page OEM Shop Manual, or Komatsu WA470 2000 Service Manual – Factory Specs for Wheel Loaders.

Does this manual cover the S4D102E-1 engine?

Yes, it covers that engine specifically.

What is the publication year and page count?

Published in 2000, 794 pages.

Is this manual a reprint or an original OEM?

This is an original factory shop manual from Komatsu, printed in 2000. It is not an aftermarket imitation. I’ve seen aftermarket manuals skip critical steps like the pressure release procedure before disconnecting hydraulic lines. If you use a reprint, you risk getting fuzzy diagrams and missing pages. This manual is the real deal – the same one used by Komatsu dealers. You get the actual OEM drawings, torque specs, and troubleshooting flowcharts. No condensation, no reinterpretation.

What sections cover hydraulic system testing?

Section 20 covers all hydraulic pressure tests for work equipment, swing, and travel circuits. Section 10 explains the structure and function of the hydraulic components including the control valve and CLSS.

All that troubleshooting time adds up. Save yourself the headaches. Access the Factory Manual now.