Description

Komatsu PC340LC-7, PC340NLC-7 Workshop Manual

If you are wrenching on a Komatsu PC340LC-7, PC340NLC-7 Workshop Manual is what you need bolted to the bench. I have seen too many guys go after a control valve blind, using a generic torque chart from some third-party website. That ends with stripped threads on a merge-divider valve or a PPC valve that leaks because somebody used the wrong inch-pound bolt spec. This manual is 910 pages of the actual Komatsu factory data – the same book the dealer techs get. No aftermarket interpretation, no missing pages, no guesswork.

I have been an ASE Master Tech for twenty‑eight years. When I torque a head bolt, I want the OEM number printed in front of me. This manual gives you exactly that. The standard tightening torque table is right there in the foreword section so you can reference it while a job is half‑disassembled. You do not need to flip through a dozen online forums hoping someone remembered the right value.

What You Actually Get: 910 Pages of Factory Data

This is not some condensed version. The table of contents runs seven sections deep: 00 Index, 01 Specification, 10 Structure/Function/Maintenance (with nine subsections including Power train, Undercarriage, Hydraulic system in three parts, Electrical system), 20 Standard value tables, 30 Testing and adjusting, 40 Troubleshooting, 50 Disassembly and assembly. That is real depth. If you need to measure swing circle bearing clearance or adjust valve clearance on the engine, the procedure is written out step‑by‑step with the required tools and pressures. Page numbers: the foreword includes the standard tightening torque table. For example, you want the charge pressure? It’s in the Testing and adjusting section.

Look at the hydraulic system breakdown – it covers everything from the hydraulic pump to the center swivel joint, travel motor, swing motor, and each cylinder. The CLSS (Closed‑Center Load Sensing System) is explained with valve function diagrams. That alone can save you hours of head‑scratching when a drift prevention valve does not seat.

Torque Specs: Why the Standard Tightening Torque Table Matters

I cannot tell you how many times I have watched a DIYer ruin a steel fuel line fitting because they thought “German torque” (gudentight) was enough. This manual includes the official Komatsu torque table with conversion factors. It also lists specific torque values for engine related parts, chassis components, and hydraulic fittings. If you are rebuilding the final drive or the sprocket, do not trust a forum post. Trust the 910‑page document that Komatsu printed.

Hydraulic System Breakdown: Part 1, 2, 3 – What’s Inside

The manual cuts the hydraulic system into three separate sections. Part 1 covers the layout, tank, filter, and pump. Part 2 goes into the control valve, CLSS, merge‑divider valve, and the attachment circuit selector valve. Part 3 handles the PPC valve, solenoid valves, accumulators, return oil filter, center swivel joint, travel motor, swing motor, and hydraulic cylinders. If you are chasing a drift issue in the boom, the Hydraulic Drift Prevention Valve section in Part 2 has the diagnosis steps. No generic wiring diagram – actual Komatsu hydraulic schematics.

For those who have never worked on a PC340NLC-7, the main difference from the LC model is the undercarriage. The manual covers both. The undercarriage section talks about track frame, recoil spring, idler, carrier roller, track roller, and shoe tension adjustment. Checking track shoe tension is in Testing and adjusting; they specify the sag measurement and the grease pressure needed.

Testing and Adjusting: Real Procedures for Real Problems

Section 30 is over 100 pages of practical tests. You get tools lists for testing – from a simple tachometer to a hydraulic pressure tester. Procedures include measuring engine oil pressure, fuel pressure, blow‑by pressure, compression pressure, air boost pressure, and exhaust gas color. There is also a specific method for bleeding air from the fuel circuit and checking for leakage. The electrical system section includes KOMTRAX terminal diagnostics, sensor pinout, and the engine control system. If you are dealing with an E‑mode code, the troubleshooting section will walk you through the failure code display and possible causes.

One thing that separates this manual from aftermarket copies: the wiring diagrams are drawn to Komatsu’s standard. They label connectors with wire colors and pin numbers. You can read the electric wire code explanation in the foreword, so there is no confusion about what “Lg” means.

Source Validity: OEM vs Aftermarket Documentation

I have seen aftermarket reprints that claim “factory specs” but omit the serial number range. This manual is the original Komatsu publication. It starts with serial numbers PC340LC-7E0 K45001 and PC340NLC-7E0 K45001 and up. The Form Number UEN00264-00 tells you it is genuine. If you are comparing this to something you found on a file‑sharing site, check the bookmark structure – this one has nested bookmarks down to the subsection level. That matters when you are on the floor with greasy hands and need to jump to “Disassembly and assembly of the swing motor” without scrolling through 900 pages.

Related Komatsu manuals you might need for a fleet: Komatsu WA65-5 WA70-5 WA80-5 2005 Workshop Manual, Komatsu WH609-1E0 WH613-1E0 WH713-1E0 WH714H-1E0 WH716-1E0 Workshop Manual, and Komatsu PW95R-2 Workshop Manual – 520 Pages of Factory Specs. If you want more background on how these hydraulic systems relate to standard Manual Transmission principles, that is a broader topic – but the Komatsu manual will give you the specific values you need. For those who also work on automotive gearboxes, a parallel resource is Manual Transmission documentation.

Does the manual include the KOMTRAX terminal system?

Yes, it is covered in the Electrical system section under “KOMTRAX terminal system”.

What serial numbers does this manual cover?

The manual applies to PC340LC-7E0 starting at K45001 and PC340NLC-7E0 starting at K45001 and up. If you have a machine built before that serial number break, some procedures may differ – especially in the hydraulic control valve and engine control module calibration. Always confirm your machine’s serial plate before using this manual for major disassembly. The foreword includes an explanation of how to read the model and serial number codes, so you can match your unit correctly.

Bottom line: if you are working on a PC340LC-7 or PC340NLC-7, this is the manual that will keep your repairs straight and your torques accurate. Do not mess around with copied PDFs that have missing pages or blurry torque tables. Access the Factory Manual from AutoRepairManuals today and keep it on your tablet or printed binder.