Description

Komatsu PC750-6, PC800-6, PC750SE-6, PC750LC-6, PC800SE-6 2000 Workshop Manual

You’ve got a customer or your own machine throwing a code, hydraulic pressure dropping, or maybe the engine won’t idle down. The last thing you want is a generic aftermarket PDF that tells you “torque to spec” without saying what that spec is. I’ve been turning wrenches for 28 years, ASE Master certified, and I run a 6-bay shop in San Antonio. I’ve seen machines come in with blown piston pumps because some DIY guy used a Haynes manual’s hydraulic pressure number that was 200 psi off. That doesn’t happen with the Komatsu PC750-6, PC800-6, PC750SE-6, PC750LC-6, PC800SE-6 2000 Workshop Manual.

This is the factory binder that Komatsu dealers use. 981 pages, printed originally in 2000, covering the SAA6D140-2 engine in those five model variants. I will walk you through what is inside and why you need it on your shop bench.

Adjusting Valve Clearance and Fuel Timing

One of the first things a mechanic needs to get right on a big Komatsu six-cylinder is the valve lash. The manual dedicates a full procedure under Testing and Adjusting – you will find Adjusting valve clearance and Testing and adjusting fuel injection timing in Section 20. Those two procedures alone can save you from pulling the head when you’re just off by 0.002 inches. The manual gives the cold clearance for intake and exhaust valves, plus the injection timing in degrees BTDC. I have used this exact section to bring a PC800-6 back to life after a field mechanic had the timing off by 10 degrees – it was belching black smoke and had zero power. This manual fixed it in one afternoon.

Structure and Function: Hydraulic Circuit & Control Valves

Section 10 of this manual is a goldmine. It covers the entire hydraulic system from the tank to the swing motor. You get the Hydraulic circuit drawing and Hydraulic piping drawing, plus breakdowns of the L.H. 5-spool control valve and R.H. 4-spool control valve. If you need to understand how the pilot oil circuit feeds the PPC valves or where the safety lock valve sits, it’s all here. The manual also includes the Actual electric wiring diagram and Electric circuit diagram. I have used those wiring diagrams more times than I can count to trace a short in the solenoid valve assembly. If you are working on a PC750LC-6 or PC800SE-6, the diagrams match the harness exactly – no aftermarket interpretation.

Why OEM Factory Specs Beat Aftermarket Manuals

I have zero patience for aftermarket documentation that says “tighten bolts to OEM spec.” Which spec? The Komatsu Workshop Manual has the actual torque values for every fastener in the machine – head bolts, main bearing caps, final drive bolts, swing circle mounting bolts. Page 20-1 starts the testing and adjusting section with standard value tables. You get Standard value table for engine related parts, Standard value table for chassis related parts, and Standard value table for electrical parts. These tables are the same ones the factory technician uses. No guesswork, no translation errors. I have seen aftermarket manuals round metric torque values to the nearest foot-pound, which can over-stress a bolt or leave it loose. This manual gives exact Newton-meter figures and foot-pound conversions from the source. If you care about your equipment holding together, you use the OEM print.

Troubleshooting the Governor and Pump Controller

The electronic control system on these machines can be a headache. The manual has an entire troubleshooting section dedicated to the Governor, pump controller [governor control system] (E mode). It lists several specific fault codes, like E-1 through E-6 for power supply issues, fuel control dial input, governor motor drive, feedback potentiometer, and battery relay output. Each code has a step-by-step diagnostic chart. I have used the Judgement table for governor, pump controller and engine related parts to isolate a bad feedback potentiometer on a PC750-6 that was surging at high idle. Saved me three hours of swapping parts. The manual also includes the Electrical circuit diagram of governor, pump controller (governor control system) so you can actually measure voltages at the controller pins.

7 Systems Covered in 981 Pages

Beyond the engine and hydraulics, the manual goes deep into the structure and function of every major subsystem: power train, swing machinery, final drive, track frame, air conditioning, and the machine monitor system. The Fuel, coolant and lubricants table in Section 01 gives you the correct grades – don’t use a universal hydraulic oil that doesn’t meet Komatsu’s specs. The Weight table is handy when you need to lift components safely. I also like the Tools for testing, adjusting, and troubleshooting list – it tells you exactly which special tools you need for things like measuring servo piston stroke or testing solenoid valve output pressure. If you are a home garage guy, you might need to rent a few tools, but at least you know what to rent.

Who Should Buy This Manual

If you own a PC750-6, PC800-6, PC750SE-6, PC750LC-6, or PC800SE-6 – or if you work on them for a living – this manual is mandatory. Beginners will appreciate the clear procedure descriptions, and pros will appreciate having the exact data without having to call the dealer. The manual also covers serial number ranges: PC750-6 from 10001 and up, PC750SE-6 from 10001, PC750LC-6 from 10001, PC800-6 from 30001, and PC800SE-6 from 30001. Check your machine’s serial against those ranges on the cover page (page 1) to confirm compatibility.

FAQ

Does this workshop manual include the engine rebuild specs for the SAA6D140-2?

Yes, it includes compression pressure, blow-by pressure, valve clearance adjustment, and fuel injection timing – all in the Testing and Adjusting section. For full engine disassembly, you also need the separate 6D140-2 Series Engine Shop Manual, which is referenced in this manual.

Can I use this manual to fix a hydraulic drift issue in my PC750LC-6?

Absolutely. Section 20 contains a specific test: Testing locations causing hydraulic drift of work equipment. It tells you how to measure oil leakage past the spools and pistons. I used it last month to diagnose a worn swing PPC valve – the procedure is clear and includes acceptable leakage rates in gallons per minute. The manual also covers testing and adjusting hydraulic pressure in the work equipment, swing, and travel circuits.

I have been through a lot of manuals in 28 years. The ones that save you money are the ones that give you the truth straight from the factory. If you want to avoid wrecking a valve train or a hydraulic pump because you guessed the torque or the pressure, get the original. Access the Factory Manual now.

Related manuals you might need: Komatsu PC750-6 PC800-6 1996 Field Assembly Instruction – if you are putting a machine together from a crate. Komatsu PC750/PC800 HYDRAULIC EXCAVATOR Field Assembly – Section: B-15 Greasing – details on proper grease specs for track tension and swing circle. For newer updates: Komatsu PC750-6 PC800-6 2004 Workshop Manual – Factory Specs.

External references on general topics: If you need background on how a Manual Transmission works, check the engineering theory. Also see Manual Transmission principles for heavy equipment.