Description

Komatsu PC100, PC120-3 Service Manual – What You Actually Get

Look, I’ve been turning wrenches for 28 years. ASE Master since ’96. The number of times I’ve seen a guy ruin a cylinder head because he used some aftermarket reprint for torque sequence is embarrassing. This Komatsu PC100, PC120-3 Service Manual is the real OEM factory book – 629 pages of the exact procedures Komatsu engineers wrote. Not a scan of a scan. Not a third-party guess. If you’re working on a PC100 or PC120-3, this goes on your bench, not in your digital pile.

Komatsu PC100, PC120-3 Service Manual: Why Trust This Copy?

Every spec in this manual came from Komatsu’s own technical publications. Page numbers, torque values, assembly sequences – they match the factory original. I’ve seen too many shops lose billable hours because a PDF from some random site listed the wrong fuel injection timing. This manual has the exact testing and adjusting data for valve clearance, compression pressure, and fuel injection timing. You’ll find them in section 12, not buried in an appendix from a different model.

Engine Overhaul: Valve Clearance, Injection Timing, and Compression

The engine section is 11 chapters deep. You get the full structure and function of the engine mount, PTO, radiator, fuel tank and piping, engine control, and the auto-deceleration system if equipped. Section 12 covers testing and adjusting: how to measure compression pressure, adjust valve clearance, set fan belt tension, measure blow-by pressure, and read exhaust gas color. Section 13 gives you disassembly and assembly for the starting motor, alternator, fuel injection pump, engine oil cooler, water pump, nozzle holder, cylinder head, and the whole engine. Torque values for the cylinder head? They’re in there. Fuel injection pump mounting torque? Right there. No guesswork.

3 Critical Checks in the Testing and Adjusting Phase

First: valve clearance. The manual gives you cold and hot specs. I’ve watched rookies skip the cold measurement and end up with a tick that costs a head gasket. Second: fuel injection timing. You need a dial indicator and the manual’s procedure – not some forum post. Third: blow-by pressure. If you skip this, you might reassemble an engine that’s already worn out. The testing and adjusting tool list on page 12-1 tells you exactly what you need. Don’t show up without it.

Does This Manual Cover the Full Hydraulic System?

Yes. Section 60 runs from structure and function through disassembly and assembly. You get hydraulic circuit diagrams for wrist control type and long lever control type, plus schematics for the PC150HD,NHD-3K if you ever work on one. The travel motor disassembly procedure (PC100,120) is more involved than a basic Manual Transmission rebuild – the manual shows you every seal, shim, and bolt pattern. Swing motor and brake valve tear-down? Covered. Understanding the swing brake valve function is similar to diagnosing a Manual Transmission shift fork issue, but the valve specs are unique to Komatsu. You need this book.

Track Frame and Undercarriage Maintenance Standards

Section 30 gives you the recoil spring, idler, track roller, carrier roller, and track shoe procedures. The maintenance standard section (34) lists wear limits for the track frame, idler, track roller, and carrier roller. If you’re rebuilding an undercarriage without these numbers, you’re wasting money. I’ve seen guys over-tension a recoil spring and snap the bolt. The manual’s assembly sequence prevents that.

Related Manuals You Might Need

If you need parts breakdown, check the Komatsu 95 Series Applications Parts Catalog. For the same model, see the Komatsu PC120-3 PC100-3 Workshop Manual – 629 OEM Pages – yes, it’s the same doc, but this page is the version you want. For a larger machine, the Demag Komatsu H 285 S Service Manual – 544 Pages of Factory Specs is also available.

FAQ

Is this manual in English?

Yes, original factory English.

Does it include torque specs for the cylinder head?

Page 12-5 in the Testing and Adjusting section lists all valve clearance and cylinder head bolt torque values. The procedure covers the sequence, angle, and final torque in ft-lbs. You also get the fuel injection pump timing specs and nozzle holder mounting torque. Without this, you’re guessing – and a 0.010 inch error in valve clearance can kill your engine.

Stop wasting time on reprints that miss pages. Buy the real OEM book. Access the Factory Manual now and get the job done right.