Description

Komatsu PC750SE-6K 1999 Workshop Manual

If you are working on a Komatsu PC750SE-6K and you don’t have the factory Workshop Manual, you are flying blind. I have seen too many guys pull a torque wrench on a cylinder head and just guess because the aftermarket book said ‘tighten to spec’ without giving the actual number. That gets expensive fast. This 1999 Komatsu PC750SE-6K Workshop Manual gives you the exact numbers from the factory. 685 pages of what Komatsu wrote, not some third-party rewrite. You need the charge pressure for the transmission? Section 20. You need the ring gear backlash? Section 40. It is all there. The manual mounts the SAA6D140E-2 engine; for engine details you go to the separate 6D140E-2 Engine Shop Manual, but this book covers everything else on the machine – structure, function, testing, disassembly, assembly, and maintenance standards.

That is the difference between a job that holds and a job that comes back.

Testing and Adjusting: Page 20-1

Section 20 is where you live when something is wrong. Hydraulic pump output pressure, pilot pressures, solenoid valve tests, travel motor neutral drift – the procedures are step by step with the exact gauge requirements and readings. Komatsu tells you which port to tap and what the spec is at standard operating temperature. Do not try to fudge these numbers. A 50 psi deviation on the main relief can cost you a pump. The manual also covers the electronic control system diagnostics, including fault code retrieval. For the transmission charge pressure, the spec is listed clearly. If you own the Manual Transmission variant, the same testing logic applies, but the Komatsu data is specific to this model’s hydrostatic setup.

Structure and Function: Section 10

Before you take anything apart, you need to understand how the hydraulic and electrical systems are laid out. Section 10 goes through the main pump, control valve, travel motors, and swing machinery. Each component gets a functional diagram and a description of the oil flow path. The electro-hydraulic control (EHC) system is explained in detail – which solenoids drive which spools and what the default fail-safe positions are. If you have ever diagnosed a no-swing condition and wished you had a wiring diagram that matched the actual machine, this section fixes that. The electrical schematics are factory originals, not redrawn. For related wheel loader models, check the Komatsu WA65-5 WA70-5 WA80-5 2005 Workshop Manual for a different hydraulic architecture.

Disassembly and Assembly: Section 30

Section 30 covers the order of operations for pulling the final drive, the swing reduction gear, the track frame, and the main pump. Each procedure lists the required special tools – Komatsu part numbers and equivalents. The manual does not skip steps like ‘remove bolts’ and then forget to tell you the tightening sequence. For the track adjuster, you get the grease relief procedure and the shim selection for track tension. Gear backlash checks are spelled out with dial indicator placement points. If you are rebuilding the swing gearbox, the thrust clearance specs are on page 30-18 (approximate; use the index for exact page). Another manual that follows the same factory rigor is the Komatsu WH609-1E0 WH613-1E0 WH713-1E0 WH714H-1E0 WH716-1E0 Workshop Manual – same attention to sequence.

Maintenance Standard: Section 40

Section 40 is the wear-limit bible. Every bushing, pin, seal, and bearing gets a standard dimension and a replace-if dimension. The track bushing inner diameter wears to a limit, and the manual tells you exactly what that number is. Piston pump cylinder block clearance? Given in thousandths of an inch. The swing circle race wear tolerance – it is in there. This section also lists all the O-ring and gasket part numbers for every joint on the machine. Using aftermarket cross-reference lists is a gamble; the OEM numbers here are the ones Komatsu stamped. For the drivetrain specifics, the Manual Transmission internals are not used on this model (it is hydrostatic), but if you deal with other equipment, the concept of factory wear specs applies the same way.

General Precautions: Section 00

The front of the manual has 9 pages of safety warnings that are not boilerplate. They cover blocking the machine before work, welding precautions, tag-out procedures, and proper lifting techniques. Komatsu printed this in 1999, but the safety practices are still current. If you skip page 00-2, you might miss the requirement to hang ‘UNDER REPAIR’ signs on the controls when working with two or more people. That kind of detail keeps you from getting crushed. The same caution applies when using the Komatsu PW95R-2 Workshop Manual – 520 Pages of Factory Specs for the smaller excavator – always respect the lockout procedures.

FAQ

Does this manual cover the SAA6D140E-2 engine?

Only partially. The manual states the engine is covered in a separate 6D140E-2 Engine Shop Manual. This book focuses on the machine itself.

What torque values are listed in the manual?

Torque specs appear throughout Sections 20, 30, and 40 for hydraulic fittings, track hardware, swing gear, and structural bolts. The values are in ft-lbs and are factory certified, not generic.

Is this a digital access or a printed book?

It is a digital PDF format of the original 1999 Komatsu printed manual, 685 pages. You can print it yourself or use it on a tablet in the shop.

Can I use this manual for the PC750SE-6K with serial number below K30055?

The manual covers machines with serial numbers K30055 and up (and 10194 and up for alternate range). Earlier machines may have differences. Check the index for applicable updates.

You have the machine. You have the tools. Now get the data that matches the engineering behind it. Access the Factory Manual and put the real numbers on your torque wrench.