Description

Komatsu PC300LC-8, PC300HD-8 2011 Service Manual

If you’re staring at a Komatsu PC300LC-8, PC300HD-8 2011 Service Manual and wondering why you bothered, it’s because the factory spec for the hydraulic pump LS valve adjustment is on page 30-1. That single number is the difference between a machine that digs and one that sits. I’ve seen guys skip the torque tables and come back with a split flange and a puddle of oil under the swing motor. Don’t be that guy. This manual is 1097 pages of what Komatsu actually published — not a scanned copy from a third party that’s missing the running changes.

Standard Tightening Torque Tables

You get the exact torque values for every fastener on this machine — bolts, nuts, hose nuts, split flange bolts, flared nuts, O-ring boss joints, and plugs. The manual dedicates a full section to these tables. No generic “tighten to spec” nonsense. You want the torque for a taper seal hose fitting? It’s in the table. Face seal? Also there. I keep a copy on the bench next to my torque wrench because I don’t trust my memory after a 12-hour shift. If you’re rebuilding a Komatsu PC300LC-8 final drive, you need those numbers on page 10-1. That’s the structure and maintenance standard section where the sprocket and track frame specs live.

Hydraulic System: CLSS and Valve Functions

Hydraulic troubleshooting without the factory diagram is a waste of time. This manual covers the Closed Center Load Sensing System (CLSS) with valve function descriptions for the unloader valve, pressure compensation valve, boom regeneration circuit, merge-divider valve, and more. You get the hydraulic circuit diagram and the names of every component. The boom drift prevention valve? It’s in there. The arm regeneration circuit? Same. Section 10 breaks down the hydraulic pump type HPV125+125 with LS valve, PC valve, and EPC valve adjustments. If you’re swapping a travel motor on the PC300HD-8, the manual gives you the parking brake specs and safety valve settings. Do not eyeball that.

Testing and Adjusting – Section 30

Page 30-1 kicks off the testing and adjusting procedures. This is where you prove your work. The manual walks you through engine speed sensor checks, boost pressure sensor tests, and pump performance adjustments. You set the hydraulic pressures using the factory numbers, not the ones some guy on a forum posted. I’ve caught two machines that were running 500 PSI over spec because someone used a generic chart. That kills seals. If you want to verify the LS control function, the manual shows the system diagram and the electronic control logic. No second-guessing.

3 Sections That Cover the Undercarriage

Track frame, recoil spring, idler, carrier roller, track roller, track shoe, and triple grouser shoe — all covered for both the PC300LC-8 and PC300HD-8. The manual separates them. You get the final drive dimensions, sprocket specs, and swing circle data. If you’re pressing bearings out of the travel motor on the HD model (type KMV200ADT-2), the disassembly procedures are in section 50. This isn’t a generic manual that lumps everything together. Komatsu designed this for mechanics who know that a .010-inch wear allowance matters on a pinion gear.

Safety Section: What Most Guys Skip

I’ve worked with guys who ignore the safety pages. That’s how you get a boom dropping on your leg. The manual starts with a full safety notice — general precautions, preparations for work, and precautions during work. It includes hoisting instructions with wire rope ratings. The push pull coupler section shows disconnection and connection procedures for three different types. Treat this like you would a Manual Transmission rebuild manual — follow every step exactly. There’s no room for shortcuts when you’re handling a 50-ton excavator.

If you also work on similar models, you might need the Komatsu PC350LC-8, PC300LC-8, PC300-8, PC350-8 Workshop Manual – 989 Pages for additional reference. For the PC350 series, the Komatsu PC350LC-8 PC300LC-8 PC300-8 PC350-8 Workshop Manual 1025 Pages offers overlapping coverage. And if you run older Demag machines, the Demag Komatsu H 285 S Service Manual – 544 Pages of Factory Specs is worth having. This manual is for the 2011 models — serial numbers A90001 up for the LC, A87001 up for the HD. Check your serial number before you order.

Torque matters. Period.

FAQ

Does this manual cover the PC300HD-8?

Yes, it covers both LC and HD variants.

What torque specifications are listed?

The manual includes standard tightening torque tables for bolts and nuts, hose nuts, split flange bolts, flared nuts, O-ring boss piping joints and plugs, plus taper seal and face seal hoses. That covers every threaded connection on the machine. You don’t need to guess.

Is this an OEM manual or a reprint?

This is the original factory manual from Komatsu, published August 2011.

What sections are included for diagnostics?

Section 30 (Testing and Adjusting) and Section 40 (Troubleshooting) give you the step-by-step procedures.

If you’re serious about keeping your Komatsu PC300LC-8 or PC300HD-8 running at peak efficiency, you need the factory data. Not a photocopy from a guy who sells manuals on eBay. Not a PDF with missing pages. This is the real thing — 1097 pages, OEM diagrams, and the specs Komatsu used on the assembly line. Access the Factory Manual now and stop wasting time guessing.