Description

Komatsu PC35R-8, PC45R-8 Technical Manual

You’ve got a Komatsu PC35R-8 or PC45R-8 on the lift. Hydraulic fluid is weeping from the swing motor seal. The track tension feels off. You reach for a manual — if it isn’t the factory Komatsu PC35R-8, PC45R-8 Technical Manual, you’re guessing. On a compact excavator, guessing costs you parts and hours. This manual, with 282 pages of OEM procedures, gives you the numbers the factory uses. Let’s go through what’s inside.

282 Pages of Factory Procedures

That pag count isn’t filler. Section 10 covers machine structure and operation — everything from the power take-off mechanism to the CLSS (Closed Center Load Sensing) hydraulic system. Separate hydraulic schematics for the PC35R-8 and PC45R-8 are listed in that section. Section 20 is where you live when diagnosing: valve clearance adjustment, compression pressure measurement, injection timing checks, and hydraulic pressure verification. Section 30 walks through removal and installation of every major component — starter, generator, head gasket, final drive, track frames, even the cab. Section 40 gives maintenance standards for the swing circle, final drive, sprocket, and rollers. Page 40 in the PDF? That’s the maintenance section. Every torque value comes from the factory, not a third-party translation.

Komatsu PC35R-8 PC45R-8 Technical Manual: What’s Inside?

Section 10 alone includes the hydraulic pump, control valve, swing motor, travel motor, cylinders, accumulator, PPC valves for both work equipment and hydraulic hammer, and the full wiring diagram in three parts. If you’re chasing an electrical gremlin, you need those factory wire colors and connector pinouts. Aftermarket diagrams often miss the load-sense signal path. This manual doesn’t.

Are Aftermarket Manuals Worth the Risk?

Aftermarket compilations of Komatsu specs are dangerous. I’ve seen torque values off by 20 ft-lb on final drive bolts — that’s a $1,500 repair when it loosens up. This manual is an original factory print (in Russian, but the numbers and diagrams are universal). The torque charts in the “Normative Torque Values” section are directly from Komatsu’s engineering. The safety section at the front tells you lifting points, lockout procedures, and pressure-release steps. Skip that and you risk a hydraulic injection injury. A Manual Transmission rebuild has nothing on the pressures in this hydraulic system — over 3,000 psi. Respect it.

Hydraulic System Schematics for Both Models

Unlike a one-size-fits-all manual, this one gives you separate hydraulic diagrams for the PC35R-8 and PC45R-8. The PC45R-8 has a slightly different pump flow and control valve setup. The CLSS (load sensing) adjustment procedure is spelled out step by step in section 20. For the PC35R-8, the pressure check points are on different circuits. If you’re swapping a pump or control valve between models, you need the distinct schematics. The manual lists the hydraulic system schematic for each model explicitly — not a generic diagram.

Diagnosing Hydraulic Drift Without Guesswork

Section 20 includes a specific procedure: “Check of hydraulic drift — analysis of causes of drift.” It shows how to isolate cylinder leakage from swing motor leakage. You’ll test each circuit with a flow meter or pressure gauge. The manual gives the allowable drift rates. If you’ve ever had a customer complain about the boom dropping overnight, this is the procedure that finds the bad seal. It also covers checking the rotary joint for internal leakage — a common failure point that many techs miss. The valve clearances for the PPC (pilot) circuit are in the same section. Adjust those wrong and the machine becomes jerky.

Safety: Lifting Points and Lockout Procedures

First few pages: lifting instructions for components. The manual tells you which tie-down points are structural. It also covers releasing residual pressure from the hydraulic tank before any work. That’s a step you don’t skip. A charged accumulator can blow hydraulic oil at 200°F. Section 30 includes lockout steps for the starter circuit and the swing lock. If you’re working alone, clip those pages to your toolbox. The manual even has a section on proper jacking points for the track frame. Aftermarket manuals often omit these details — they assume you know. Komatsu doesn’t.

Need the Komatsu PC35R-8 PC45R-8 Shop Manual for an earlier serial number? That’s a different binding. For the 2001 service edition, check the Komatsu PC35R-8 PC45R-8 2001 Service Manual. If you work on bigger iron, the Demag Komatsu H285 S Technical Manual – Shop PDF 498 Pages covers the heavy stuff. Understanding complex gear trains is easier if you’ve rebuilt a Manual Transmission — same principles of backlash and preload apply here to the final drive.

Frequently Asked Questions

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

Yes. Both models from serial numbers F20932 (PC35R-8) and F21251 (PC45R-8) upward.

Is the manual in English?

The manual is the factory Russian-language edition. However, the torque charts, hydraulic diagrams, and exploded views use universal notation and numbers. You can perform most repairs using the diagrams alone.

What torque specs are included?

The manual includes factory torque values for all critical fasteners: engine head bolts, hydraulic fitting connections, track frame bolts, swing circle mounting bolts, and more. Section 40 (Maintenance Standards) lists specific values for the swing circle, final drive, sprocket, and rollers. For example, the swing circle bolt torque is not published in any aftermarket manual. You’ll find the exact Nm value in the table. Also included are hydraulic pressure check values for the pump, control valve, and LS system. These specs prevent overtorquing and component failure. Using aftermarket values can lead to leaks or breakage.

Can I use this for the PC45R-8?

Yes. The manual covers both models. Section 10 includes separate hydraulic system schematics for each model.

If you’re keeping that Komatsu excavator running at factory spec, this Technical Manual is the only source that guarantees original data. The torque tables, hydraulic pressure charts, and step-by-step removal/installation procedures are all here. Skip the aftermarket copies. Buy the real deal. Access the Factory Manual now and get the specs you need.