Description

Komatsu PC800, PC800LC, PC800SE, PC850, PC850SE Workshop Manual

I’ve been wrenching on heavy iron for 28 years. If you’re about to tear into a Komatsu PC800 or PC850 series excavator without the factory book, you’re working blind. Aftermarket PDFs with missing torque values and generic diagrams will cost you time and parts. This Komatsu PC800, PC800LC, PC800SE, PC850, PC850SE Workshop Manual gives you the exact specs that came from the line – 1327 pages of verified data. I’ll tell you what’s inside and why you need it on your bench.

First thing you should know: this is the OEM manual, not a third-party reprint. The hydraulic pump control system in a PC800SE is not the same as a PC850SE – the manual spells out differences clearly. You get section 10 covering structure and function for all models: engine coupling, cooling system, power train, swing circle, final drive, track frame, and the entire hydraulic system layout from the tank and filter to the solenoid valves and accumulator. Wiring diagrams for the electrical system include the KOMTRAX monitoring and engine control. No guesswork.

Engine and Hydraulic System Coverage – What’s Actually in the Book

The manual breaks into seven major sections after the index. Section 00 has the foreword, safety notices, how to read the shop manual, handling hydraulic components, handling electric equipment, and – pay attention – the standard tightening torque table. That table on page 00-34 lists thread sizes and torque in ft-lbs. I’ve seen techs snap bolts because they guessed. Don’t be that guy.

Section 10 runs over 200 pages on structure and function. You get the entire hydraulic component layout: pump, servo valve, self-pressure reducing valve, cooling fan pump and motor, control valve, straight-travel valve, swing motor, travel motor, PPC valve, solenoid valve, accumulator, quick return valve, and every filter in the system. The electrical section covers engine control, monitor system, sensors, and the KOMTRAX telematics. If you need to understand how the pump control system regulates flow, it’s all here with diagrams.

Does This Manual Include the Factory Torque Specifications?

Yes, and they’re not generic. The standard tightening torque table in section 00 is model-specific. You’ll find torque values for bolts on the track frame, final drive, swing circle, and every hydraulic fitting. On top of that, section 20 gives you the standard value tables for the engine and machine – clearances, pressures, flow rates. Need to know the swing motor relief pressure? It’s in the hydraulic component specs. I always cross-check the torque table before reassembling anything that holds oil or pressure.

1327 Pages of Structured Repair Data

This isn’t a condensed guide. It’s a full workshop manual with sequential steps. Section 30 is titled “Testing and adjusting” and covers tools needed, then goes into engine speed testing, intake air pressure, exhaust gas temperature, valve clearance adjustment, compression tests, blowby, oil pressure, fuel system handling, belt tension, and more. For the hydraulic system you get procedures for testing and adjusting oil pressure in work equipment, swing, and travel circuits, PPC valve output, solenoid valve outlet pressure, fan speed, and oil leakage. The troubleshooting section (40) includes failure code tables and symptom diagnosis. That’s where you save hours.

Use the Standard Tightening Torque Table Before You Turn a Wrench

I can’t overstate this: ignore the torque table and you’ll be buying parts. The manual gives you the specs in ft-lbs. For critical fasteners like the swing circle bolts, final drive mounting bolts, hydraulic pump mounting, and track frame bolts, you have to hit the value. The table is on page 00-34, and section 20 repeats key values in the standard value tables. Keep a copy of that page laminated on your toolbox.

Testing and Adjusting: The Section That Saves Your Hydraulic Pump

Section 30 starts with a list of required tools – pressure gauges, flow meters, tachometers. Then it walks through engine tests: page 30-19 covers testing engine speed. You’ll learn how to check blowby pressure and adjust valve clearance. The hydraulic testing procedures are where this manual earns its pay. You get step-by-step for measuring fan circuit oil pressure, fan pump EPC current, and solenoid valve outlet pressure. The PM clinic subsection includes an undercarriage inspection report template – useful for fleet owners. Every test includes the pass/fail criteria from the standard value table.

Understanding the swing drive gearbox is similar to a Manual Transmission in terms of gear mesh patterns. The travel motor reduction works like a Manual Transmission but with planetary gears – the manual shows the breakdown.

Audience Fit – Who Should Own This Manual

This is for anyone who owns or services a Komatsu PC800, PC800LC, PC800SE, PC850, or PC850SE excavator. Professional mechanics will use the troubleshooting section to cut diagnostic time. Shop owners need it for liability – if a tech bolts a swing motor with the wrong torque and the machine fails, that’s on you. DIY owners and equipment operators who do their own maintenance will keep the machine running longer. Beginners can follow the testing procedures if they have the right tools. The manual assumes you know how to use a wrench, but gives you the numbers.

Source Validity – Why OEM Beats Aftermarket

I’ve tested aftermarket manuals against this one. They leave out details – like the exact order of tightening for the hydraulic pump mounting bolts. This manual came from Komatsu. The revision notice on page 3 shows it’s the 3rd revision from February 2012, with a list of revised pages. That means every spec is current. The diagrams are original, not redrawn. If you want a manual that matches the machine on your shop floor, this is it.

Does this manual cover all models listed?

Yes. It covers PC800, PC800LC, PC800SE, PC850, and PC850SE with serial numbers 65001 and up. Section 01 has specifications drawings and spec tables for each variant.

Can I use this for a PC750?

No. The PC750 has different hydraulic and power train specs. You need the PC750-specific manual. Check our related manuals below.

Are torque values in ft-lbs or Nm?

The standard tightening torque table uses ft-lbs. The conversion table in section 00 lets you convert if needed. Most values are also listed in Nm in the standard value tables.

Does the troubleshooting section include electrical fault codes?

Yes. Section 40 includes a failure codes table and symptom troubleshooting for electrical system issues. It also covers the KOMTRAX system and engine controller voltage handling.

If you want to keep your Komatsu PC800 or PC850 running at spec, stop using generic instructions. Access the Factory Manual now – you’ll have the full PDF on your tablet, searchable, printable, and ready for the next job.

Related Manuals

• Komatsu PC800, PC800LC, PC800SE, PC850, PC850SE Installation Manual – 189 Pages”>Installation manual – 189 pages for setup guide
• Komatsu PC750/PC800 Workshop Manual 2004 — 730 Pages OEM Specs”>PC750/PC800 2004 OEM manual – 730 pages
• Komatsu PC800/PC850 Workshop Manual – Factory Specs, 1327 Pages”>Same manual listed as separate product