Description

Komatsu PC35R-8, PC45R-8 Workshop Manual

You are working on a PC35R-8 or PC45R-8 hydraulic excavator and you need the factory torque spec for the cylinder head bolts. You grab a third-party manual and the number is off by 10 ft-lbs. That is how you warp a deck and blow a head gasket. I have seen it. The Komatsu PC35R-8, PC45R-8 Workshop Manual from AutoRepairManuals is the factory document. 282 pages. No guesswork. Every torque value came off the same line those machines were built on. You want the Standard Tightening Torque table? It is in there. You want the injection timing procedure? Section 20. You want the hydraulic circuit diagram for the PC45R-8? It is on the page labeled HYDRAULIC CIRCUIT DIAGRAM PC45R-8. That is how you do the job right the first time.

Standard Tightening Torque: Why Factory Specs Matter

Under the chapter STANDARD TIGHTENING TORQUE, this manual lists bolt grades, thread sizes, and the exact foot-pounds for every fastener on the machine. Not a generic range. Not “tighten to spec” from a haynes manual. Komatsu engineers wrote the numbers. If you are rebuilding the swing circle or the final drive, you need those numbers. I have torqued head bolts on a Komatsu 6D95 engine and I will tell you: 0.5 ft-lb off on a main bearing cap and you are buying new hardware. The manual gives you the number. Use it.

Hydraulic Circuit Diagrams for PC35R-8 and PC45R-8

Both models get their own full hydraulic circuit diagram in Section 10. The PC35R-8 diagram covers the pump, control valve, CLSS, swivel joint, swing motor, travel motor. The PC45R-8 diagram is separate because the travel motor is different. You do not guess which line is the pilot pressure feed. You read the diagram. There is also the ELECTRICAL DIAGRAM in three parts – 1/3, 2/3, 3/3 – so you can trace a short in the solenoid valve circuit without lighting up a multimeter probe. If you are diagnosing a drift in the boom, the manual gives you a whole sub-section: CONTROL OF HYDRAULIC DRIFTS – ANALYSIS OF THE CAUSES OF A DRIFT. That is the kind of specific troubleshooting you do not get from a reprint.

Testing and Adjustments: Engine Speed and Valve Clearance

Section 20 is where you live when the machine is running rough. CHECKING THE ENGINE SPEED – they give you the procedure with special tool numbers. ADJUSTMENT OF VALVE CLEARANCE – the intake and exhaust gaps are listed. MEASUREMENT OF THE COMPRESSION PRESSURE – with the pressure range in psi. CONTROL AND ADJUSTMENT OF THE INJECTION TIMING – that procedure alone can save you from pulling the injection pump for no reason. There is also REGULATION OF THE PC VALVE and CONTROL AND REGULATION OF THE LS DIFFERENTIAL PRESSURE. If you do not know what those are, do not touch them without this manual. You will mess up the hydraulic pump output and the machine will stall under load.

Removal and Installation: Cylinder Head and Injection Pump

Section 30 tells you exactly how to pull the cylinder head, alternator, starter motor, injection pump, nozzle holder, water coolant pump, and the engine-pump group. The manual includes PRECAUTIONS TO BE TAKEN WHILE WORKING – that is not fluff. That is warnings about residual pressure in the hydraulic tank and how to bleed air from the circuits. You skip the precaution on page 48 [DATA NEEDED] and you get a face full of hot oil. I have seen it. The manual lists the SPECIAL TOOLS for each removal job. You will know if you need a puller or a press before you start. And the torque sequence for the cylinder head is in there – bolt order and angle tighten steps. No aftermarket manual has that.

Audience Fit: Who Needs This 282-Page Manual?

If you are a home-shop mechanic who bought a used PC35R-8 to clear brush on your property, you need this. If you are a shop tech chasing a hydraulic leak on a PC45R-8 that came in with a dead swing brake, you need this. Beginners can use the HOW TO READ THE SHOP MANUAL section at the front. It explains the symbols, the wire codes, and the coating materials. Professionals will go straight to the torque tables and the hydraulic circuit diagrams. The manual does not assume you have a full Komatsu tool set, but it tells you what you need. And if you are a shop owner, you buy one copy and put it on the bench so your techs stop using the wrong torque for the idler recoil spring. That is how you avoid comebacks.

Related manuals: Komatsu PC35R-8 PC45R-8 Shop Manual”>Komatsu PC35R-8 PC45R-8 Shop Manual, Komatsu PC35R-8 PC45R-8 2001 Service Manual”>Komatsu PC35R-8 PC45R-8 2001 Service Manual, Komatsu PC35R-8 PC45R-8 Technical Manual – Factory OEM Shop Manual”>Komatsu PC35R-8 PC45R-8 Technical Manual – Factory OEM Shop Manual. For general transmission theory, see Manual Transmission”>Manual Transmission and Manual Transmission”>Manual Transmission on Wikipedia.

Does this manual cover both the PC35R-8 and PC45R-8?

Yes. It covers both models in one document, with separate sections for each model where differences exist, like the travel motor and hydraulic circuit diagram.

What kind of torque specifications are included?

Standard tightening torque for all bolts, plus specific torque values for engine, hydraulic, and drivetrain components. The table is organized by thread size and grade.

Is this the official Komatsu factory manual?

Yes. This is a direct scan of the Komatsu shop manual. It comes from the Komatsu utility series documentation. Not a reprint or a third-party summary.

Can I use this to rebuild the final drive?

Yes. Section 30 includes removal and installation of the final drive. Section 40 covers standard maintenance. The torque specs for the sprocket and final drive bolts are in the STANDARD TIGHTENING TORQUE chapter.

Do not waste time with generic manuals that leave out the LS differential pressure adjustment or the PC valve regulation. Get the factory document. Access the Factory Manual now and put the right torque on every fastener.