Description

Komatsu PC800-8, PC800LC-8 Workshop Manual

If you have ever tightened a hydraulic fitting on a Komatsu PC800-8 using a generic aftermarket spec and watched it weep oil the next morning, you already understand why this manual exists. I have seen more than one shop lose a billable day because somebody grabbed torque values off a forum instead of pulling the factory page. This is the real thing – 798 pages, OEM release, covering both the PC800-8 and the PC800LC-8 from serial number 50001 up. No reprints, no third-party summaries, no missing sections.

Engine and Cooling System: Coupling and Lubrication

Section 10 of the manual breaks down the engine and cooling system into the coupling, coupling lubrication, radiator, and oil cooler. If you are pulling the coupling on a Galeo series, the clearance and bolt torque are not something you guess. The manual gives you the standard tightening torque table on page 1 of the foreword section – follow it. The oil cooler flow path is drawn out with pipe routes that match the actual machine, not a generic schematic.

Hydraulic System, Parts 1 and 2 – What the Factory Includes

Hydraulic system is split into two parts. Part 1 covers the hydraulic pump, pump control mechanism, EPC valve, self pressure reducing valve, cooling fan pump and motor. Part 2 gets into the spool valves – left-hand 5-spool, right-hand 4-spool, straight-travel valve, swing motor, center swivel joint, travel motor, PPC accumulator, and all three filters (return, line, drain). If you are chasing a sluggish swing function, the troubleshooting section (40) matches failure codes to the exact valve body. I have used the L.H. 5-spool control valve section to diagnose a stuck spool without pulling the whole bank. It works.

Standard Service Value Table: The Specs You Need

Section 20 is a standard service value table for both engine and chassis. This is where you find the acceptable wear limits for the swing circle, track components, and hydraulic components. The manual lists the values in a table format – no narrative fluff, just numbers. You want the clearance on the swing circle bearing? It is in there. You need the track shoe tension range? Same table. Keep a copy of this section laminated in your toolbox because it saves pulling the whole binder out every time.

Testing and Adjusting – Real Procedures, Not Theory

Section 30 is split into five parts and covers exactly how to measure engine speed, intake boost pressure, exhaust gas temperature, valve clearance, compression pressure, blow-by, and oil pressure. Every test has a required tool list – the manual calls out specific Komatsu tools and gives you the part numbers. If you do not have the special tool, it tells you an alternative method. For example, measuring main pump control pressure: you need a pressure gauge set, and the manual gives you the port location on the pump. No guesswork.

Why OEM Documentation Beats Aftermarket

I have seen aftermarket manuals that combine three different machine models into one PDF and call it a day. This one is serial-number-specific. The wiring diagrams in the electrical system section (10 – Electrical system) match the actual harness for PC800-8 machines built after 50001. Aftermarket manuals often swap pin numbers or leave out the monitor system diagnostics. That gets you into trouble fast. The Komatsu PC800-8, PC800LC-8 Workshop Manual is the same document the dealer techs use. It includes the safety notice at the front – read it. Handling electric equipment and hydraulic components requires the steps laid out in the foreword. Skip them and you risk component damage or personal injury.

If you are working on the power train, the manual covers the swing machinery, swing circle, final drive, and sprocket in one section. The power train chapter gives exploded views with part numbers. Compare that to a generic manual that shows a generic final drive cross-section. There is no comparison.

What About Undercarriage and Frame?

Section 10 also includes the undercarriage and frame – track frame, recoil spring, idler, carrier roller, track roller, and track shoe. If you are rebuilding the idler or replacing a carrier roller, the manual gives you the disassembly sequence and torque specs for the bolts holding the track frame. The spec table at the back (Section 20) lists the acceptable wear limits for the idler tread diameter. I do not trust any aftermarket source for those numbers.

Does This Manual Cover the Electrical System?

Yes. There is a full electrical system section with engine control, electric control, monitor system, and sensors. The troubleshooting section (40) is organized by failure code (E-mode, H-mode, S-mode). If your monitor displays a code, you go directly to the troubleshooting part of the manual and follow the flowchart. I have used the E-mode section to trace a faulty sensor on a PC800-8 without replacing parts blindly. The wiring diagrams are clear and coded with the electric wire code explained in the foreword.

Who Should Buy This Manual?

If you are a shop owner with a PC800-8 or PC800LC-8 on your lot – get it. If you are a field mechanic who works on these excavators regularly – you need this on your tablet. If you are a DIY owner-operator who wants to avoid dealer labor rates – this manual pays for itself the first time you diagnose a hydraulic issue without calling a tech. Beginners will benefit from the step-by-step testing procedures, but you need to be comfortable with basic mechanical work and using precision tools.

I do not recommend this manual to someone who has never turned a wrench. It is a factory workshop manual, not a beginner’s guide. But if you have basic skills and a torque wrench, you can follow the instructions. For example, adjusting valve clearance: the manual gives you the valve adjustment procedure on page Testing and adjusting, Part 1 – the sequence is clear, and the clearance values are in the standard service value table.

One more thing – the manual includes a conversion table and standard tightening torque table at the front. Keep that page handy. You will reference it often.

Related manuals you might need: KOMATSU PC800-8 PC800LC-8 Operation & Maintenance Manual”>KOMATSU PC800-8 PC800LC-8 Operation & Maintenance Manual for daily checks, Komatsu PC800-8 PC850-8 Field Assembly Instruction”>Komatsu PC800-8 PC850-8 Field Assembly Instruction for disassembly/reassembly, and Komatsu PC800 PC850-8 Workshop Manual”>Komatsu PC800 PC850-8 Workshop Manual for related models. For general background on how manual transmissions work, you can check Manual Transmission”>Manual Transmission articles, but remember the factory spec always overrides internet information. The same applies to the Manual Transmission”>Manual Transmission section in this manual – it is specific to the Komatsu power train.

FAQ

Does this manual cover both the PC800-8 and PC800LC-8?

Yes. The manual is titled “PC800-8 / PC800LC-8” and covers both models from serial number 50001 and up. The content is the same for both, with variations noted where the long-track (LC) undercarriage differs.

Are torque values included for the swing circle bolts?

Yes. The standard tightening torque table at the front gives the values, and the swing circle section (Power train) lists the specific bolt torque in the maintenance standard.

Can I use this manual to troubleshoot a hydraulic failure code on the monitor?

Absolutely. Section 40 – Troubleshooting is organized by failure code (E-mode, H-mode, S-mode). Each code has a dedicated flowchart. The manual also includes a list of sensors and their test points in the electrical system section.

Does the manual include wiring diagrams for the monitor system?

It includes the electric wire code explanation and wiring diagrams in the electrical system section (10 – Electrical system). The diagrams show connector pin numbers, wire colors, and component locations. No aftermarket manual I have seen matches this level of detail.

Access the Factory Manual and keep it on your bench. I would not work on a PC800-8 without it.