Description

Komatsu PC138USLC-10 Workshop Manual

I’ve seen too many guys crack a hydraulic fitting because they used a generic torque value from a forum. That mistake costs you a $900 pump rebuild or a trip to the ER when a hose blows. The Komatsu PC138USLC-10 Workshop Manual is what you put on the bench when you don’t want to guess. It’s the exact 1388-page factory document that Komatsu ships to their own dealers. If you touch a PC138USLC-10 (serial 40001 and up), this is the only book you should trust for fuel system bleeding, electrical diagnostics, or hydraulic pressure adjustments.

1388 Pages of Factory Data

This isn’t a PDF slapped together from a third-party copy. Every page comes straight from Komatsu’s original print. The manual covers the entire machine: from the engine and cooling system down to the bucket play adjustment shims. You get the standard tightening torque table on page 00-48, the conversion table, and the full list of abbreviations. Need the charge pressure for the CLSS pump? It’s in the Standard Value Tables section. The manual doesn’t stop at specs—it explains how to read the electric wire code and how to handle push-pull type couplers on hydraulic lines.

Fuel System and Electrical: What the Manual Covers

Working on the fuel system without factory guidance is a bad day waiting to happen. The manual dedicates a full subsection to handling equipment of fuel system devices—bleeding air, testing fuel return rate, and checking for leakage. On the electrical side, you get the complete wire code legend, sensor locations, and the KOMTRAX system overview. If you’re chasing a no-start or a monitor error, turn to section 10 (Structure and Function) for the machine monitor system and the electrical control system diagrams. The level of detail here matches what you’d find in a factory Manual Transmission rebuild guide—only this is for a hydraulic excavator.

Does This Manual Cover the Hydraulic System?

Yes, and it goes deep. Section 10 has a full hydraulic system layout: main pump, control valve, swing motor, travel motor, PPC valves, solenoid valve group, and the attachment circuit selector valves. You get the CLSS circuit, the center swivel joint, and the accumulator circuits for both low and high pressure. When you’re testing and adjusting hydraulic pressures, section 30 gives you the step-by-step—releasing remaining pressure, testing oil pressure in work equipment, swing, and travel circuits, and isolating hydraulic drift causes. This isn’t a theory book; it’s a workbench binder with the exact valve clearances and shim thicknesses from the factory.

Standard Tightening Torque Table – Why It Matters

Every bolt on this machine has a spec. The manual’s standard tightening torque table lists values for metric coarse and fine threads. I don’t care how many years you’ve been turning wrenches—you don’t eyeball torque on a swing circle bearing or a cylinder head bolt. Page 00-48 has the full table. Use it. The manual also includes the conversion table for inch-pound and foot-pound equivalents, so you don’t have to run a calculator while your hands are greasy.

3 Systems That Require Precise Adjustment

Some adjustments you can’t afford to skip. First, the engine: testing valve clearance, compression pressure, and fuel pressure. Second, the undercarriage: track shoe tension testing and adjusting—too loose and the track derails, too tight and you destroy the idler cushion. Third, the hydraulic PPC valve output pressure. The manual walks you through each with the required tool list (most from Komatsu’s special tool set) and the exact sequence. Skip a step and you’ll be back in the bay chasing a hydraulic drift.

Source Authenticity: OEM vs Aftermarket

I don’t trust aftermarket documentation. They copy the pictures wrong, round torque values to convenient numbers, or omit the safety notices. This manual is an original Komatsu factory print—no reprints, no generic third-party scans. The first page lists serial numbers 40001 and up. The foreword includes the important safety notice about handling intake system parts and hydraulic equipment. If you’ve ever had a fuel injection line burst on you, you’ll appreciate that they show you the correct way to depressurize the system before touching a fitting. That’s the kind of detail you only get from the manufacturer.

Related manuals for other Komatsu models: Komatsu WA65-5 WA70-5 WA80-5 2005 Workshop Manual, Komatsu WH609-1E0 WH613-1E0 WH713-1E0 WH714H-1E0 WH716-1E0 Workshop Manual, and Komatsu PW95R-2 Workshop Manual – 520 Pages of Factory Specs.

Frequently Asked Questions

What serial numbers does this manual cover?

40001 and up.

Does it include torque specifications?

Yes, on page 00-48 you’ll find the standard tightening torque table. The manual also has standard service value tables for engine, machine, and electrical systems.

How do I adjust the track shoe tension?

Turn to the Undercarriage section in Testing and Adjusting (section 30). The manual covers testing and adjusting track shoe tension with a step-by-step procedure, required tools (track tension gauge), and spec values. You follow the sequence to avoid damaging the idler cushion or over-stressing the track frame. Don’t guess – use the factory spec provided in the Standard Value Tables. The procedure includes measuring sag distance and adding or removing grease from the idler cushion. If you skip the safety step of blocking the track, you could get hurt.

Is this manual suitable for beginners?

If you can read a torque wrench, yes.

The same attention to detail applies to any factory Manual Transmission document—this is the real deal. Access the Factory Manual and keep it on your tablet or print the sections you need. Your machine will run longer, and you won’t be chasing leaks or blown seals because you used the wrong spec. Get the Komatsu PC138USLC-10 Workshop Manual now.