Description

Komatsu WA115-3, WA115-3H 2002 Workshop Manual

If you have ever cracked open an aftermarket guide and found torque values that didn’t match the bolt you just snapped, you know why Komatsu WA115-3, WA115-3H 2002 Workshop Manual belongs on your bench. Forty years turning wrenches in San Antonio taught me one thing: skip the OEM manual and you are guessing. This is the factory book, printed in 2002, covering serial numbers WA115H30051 and up. 174 pages of the exact data Komatsu sent to its dealers. No reprints, no third-party edits. Page 1 tells you the WA115-3H uses the S4D106-1HC engine. That kind of specific information keeps you from ordering the wrong parts.

Hydraulic Drive System Coverage: 20 km/h and 35 km/h Variants

Two different powertrain configurations exist for these loaders. The manual dedicates whole subsections to each, including the closed circuit, variable displacement pump with regulating valve, charge pressure limiting valve, and the 4/3 way valve with direction control solenoids. Need to understand the pressure cut-off valve or the safety/charge valve? It is all here. The variable displacement motor section alone is worth the price if you have ever had to rebuild one blind.

What Torque Values Are in the General Section?

Torque list – screws and nuts appears in the 01 GENERAL chapter. That table lists factory torque specs for critical fasteners on the WA115-3 and WA115-3H. Use aftermarket charts and you will over-torque a steering cylinder bolt or under-torque the axle mounting nuts. The manual also includes lubricants and operating mediums, fuel specifications, coolant, grease, and filter change intervals. Page 2 of the contents shows the full layout so you do not waste time flipping.

3 Reasons to Trust Factory Specs Over Aftermarket

First, the safety section (00 SAFETY) covers hoisting instructions, precautions during work, and proper jacking points. Aftermarket manuals skip this or give generic advice. Second, the wiring diagrams in Chapter 90 – five separate figures – are Komatsu originals. Third, the testing and adjusting chapter (20) gives standard value tables for engine, chassis, and electrical parts, plus specific procedures like injection nozzle pressure testing and brake disc wear check. You cannot get this accuracy from a third-party reprint.

Fuel System: What the Manual Covers

Fuel gets a dedicated subsection under basic procedures of maintenance. That covers storing oil and fuel, filters, and the fuel level sensor. The sensor itself is listed in the sensors section of STRUCTURE AND FUNCTION. If you are chasing a fuel level issue on a WA115-3H, the manual shows you the exact resistance values and wiring path. No guesswork.

Understand the Wiring Diagrams Before You Start

Five wiring diagrams (Fig. 1 through 5) appear in both Chapter 10 and the Appendix. These are not aftermarket redraws – they are the original Komatsu electrical schematics. Use them to trace the engine stop/start/preheating circuit, the monitor display sensors, and the optional air conditioner. The manual even covers the ribbon heater temperature sender unit. A Manual Transmission has simpler wiring; this loader’s electro-hydraulic controls demand the real diagrams.

Shops waste billable hours because they rely on memory or aftermarket shortcuts. Every time I see a rookie tech pull a torque value from a generic app, I send them to the factory manual. This one has the exact charge pressure limiting valve setting, the brake pedal adjustment for both speed variants, and the bucket positioner adjustment procedure using the proximity switch. You also get the full inch-brake pedal description – 20 km/h and 35 km/h versions. If you need to bleed the brake system, the manual steps through it correctly.

Related manuals that cover other Komatsu wheel loaders include the Komatsu WA65-5 WA70-5 WA80-5 2005 Workshop Manual, the Komatsu WH609-1E0 WH613-1E0 WH713-1E0 WH714H-1E0 WH716-1E0 Workshop Manual, and the Komatsu PW95R-2 Workshop Manual – 520 Pages of Factory Specs. Each of those follows the same OEM structure.

For context on how a Manual Transmission differs from a hydrostatic drive system, this manual explains the closed circuit and variable displacement motor in plain enough language that a home garage enthusiast can follow. But it is still a professional shop manual – expect technical depth, not fluff.

Does this manual cover both the WA115-3 and WA115-3H models?

Yes, it covers both. The WA115-3H uses the S4D106-1HC engine, and the manual includes all systems common to both models.

What is the publication year and page count?

2002, 174 pages. Printed by Komatsu in Europe.

Are the wiring diagrams in color?

No, they are black-and-white line diagrams. But they are factory originals with correct wire colors labeled.

Can I use this manual to rebuild the variable displacement pump?

Yes, chapter 10 covers the pump’s regulating valve, charge pressure limiting valve, control cylinder, and the 4/3 way valve. Disassembly and assembly instructions are scheduled for a later issue, but the structure and function section plus testing/adjusting chapter give you all the specs needed for a rebuild. The manual does not include step-by-step teardown photos for the pump, but it does give you the pressure cut-off settings and the towing procedure.

Stop wasting time on aftermarket PDFs that omit the safety notices and skip the critical torque values. This Komatsu workshop manual puts you back in control. Access the Factory Manual now and put the OEM data where it belongs – on your workbench.