Description

Komatsu D155AX-6 Workshop Manual – Real OEM, Not a Reprint

I have seen too many guys waste a Saturday wrestling a dozer that won’t move because they trusted a third-party PDF that told them to tighten the transmission valve body bolts to 45 ft-lbs. On a Komatsu D155AX-6 the spec is different—and if you get it wrong you’ll be pulling the whole power train. This Komatsu D155AX-6 Workshop Manual is the real deal: 1568 pages of factory-sourced procedures, original illustrations, and the exact torque tables the line techs use in Osaka. No reprints, no poor scans, no aftermarket interpretation.

What the 1568 Pages Cover

The manual is broken into ten sections plus the standard value tables and testing/adjusting parts. Section 01 gives you the specification dimension drawings, weight table, and the table of fuel, coolant and lubricants. Section 10 is the backbone: structure, function and maintenance standard for the engine, power train (both Part 1 and Part 2), undercarriage, hydraulic system, work equipment, cab, and electrical system. That electrical section includes the KOMTRAX system and the palm command control system—stuff that can stop you cold if you don’t have the factory wiring diagram.

Torque Specs and Fluid Capacities You Can Trust

Every bolt on this machine has a spec in section 20, the standard value table. The conversion table is right at the front. Need the hydraulic relief pressure? It’s in the testing and adjusting section. The manual even lists the tools required for each test—like the specific pressure gauge kit for measuring fan circuit oil pressure. I’ve seen techs snap off a transmission output shaft sensor because they used the wrong socket. This manual tells you the tool, the torque, and the order.

Testing and Adjusting: Step-by-Step Factory Procedures

Section 30 spans four parts. Part 1 covers engine measurements: blow-by pressure, compression pressure, valve clearance adjustment. Part 2 gets into power train oil pressure, brake pedal adjustment, and the emergency escape method when the power train locks up. Part 3 (from the bookmarks) goes into the HSS system and steering tests. Each procedure starts with a tool list and a safety notice. For example, releasing residual pressure from the fuel system is a multi-step sequence that the manual spells out because if you skip it you’re getting diesel in the face.

Why Aftermarket Manuals Fail on This Machine

Every aftermarket manual I’ve looked at for the D155AX-6 has at least one wrong torque table. They’ll list a generic M16 bolt torque that doesn’t account for the Komatsu-specific grade. Worse, they often leave out the entire section on the lockup clutch ECMV and stator clutch ECMV. Those solenoid valves have specific pressures and coil resistances that are critical for the transmission to shift correctly. This OEM workshop manual gives you those numbers because Komatsu printed them. Komatsu D155AX-6 Operation & Maintenance Manual is for daily running; this workshop manual is for when it’s torn down.

3 Systems the Manual Covers in Depth

• Power Train (Part 1 & 2): Torque converter, transmission, steering unit, brake ECMV, final drive, sprocket. Includes the HSS motor and hydraulic pump circuits.
• Hydraulic System: Work equipment control piping diagram, hydraulic tank and filter, PCCS lever, control valve, quick drop valve. The piston valve section alone saved me a week of chasing a blade-drop issue.
• Electrical System: Engine control system, deceleration potentiometer, monitor system, sensors, palm command control. KOMTRAX diagnostics are in section 40 troubleshooting.

These aren’t summaries; they’re full chapters with exploded views and part numbers. Komatsu D155AX-6/8 Bulldozer Shop Manual Index and Foreword is a separate file that shows how the sections are organized, but this main manual is the one you’ll keep on the bench.

Audience Fit: Who Should Buy This Manual

If you own a D155AX-6 and do your own major repairs—engine rebuild, transmission swap, hydraulic valve overhaul—this manual pays for itself the first time you use a correct torque spec. Home garage enthusiasts are welcome, but you need a decent tool setup: hydraulic pressure gauges, a scan tool for KOMTRAX, and a torque wrench that reads in lb-ft. Beginners should start with the operation and maintenance manual first, then step up to this when tackling overhauls. The manual assumes you know which end of a wrench to grab, but it doesn’t assume you’ve memorized every spec.

Source Validity: OEM Factory Print

This PDF is a direct scan of the Komatsu factory document, serial number 80001 and up. The original file name ends with SEN00596-12, and it’s 1568 pages because Komatsu includes every revision. I checked the table of contents against the actual factory binder structure—it matches. No third-party has added “improvements” or deleted sections. Komatsu WA65-5 WA70-5 WA80-5 2005 Workshop Manual is also available if you work on the wheel loaders, but for this dozer you want the D155AX-6 specific book.

Frequently Asked Questions

Does this manual cover the engine and hydraulic system?

Yes. Section 10 covers the engine and cooling system (radiator, cooling fan pump, fan motor). Section 10 also covers the hydraulic system with full piping diagrams, control valve breakdown, and accumulator specs. The testing and adjusting section has procedures for measuring fan circuit oil pressure and bleeding air from the fan pump.

Are torque values imperial or metric?

The standard tightening torque table in the front of the manual is in N·m, but the conversion table on page 3 gives you lb-ft equivalents. Most of the testing procedures list pressures in psi and flow rates in gal/min.

Can I use this manual for troubleshooting a no-start condition?

Check section 40 (troubleshooting). It includes failure code tables, fuse locations, and step-by-step diagnostics for KOMTRAX. The electrical section also has the engine control system wiring. Start with the failure code, then follow the test procedure.

Does it include the tools I need?

Part 1 of testing and adjusting starts with a full list of required tools for every test. For example, measuring compression pressure requires a special adaptor part number listed in the manual. No guesswork.

After you’ve used a generic PDF that gave you the wrong final drive bearing preload, you’ll understand why I only trust factory manuals. Manual Transmission knowledge helps with the power train section, but the Komatsu-specific procedures are what matter. When you’re ready to work on your D155AX-6 without wasting time on bad data, Access the Factory Manual from AutoRepairManuals and get the real specs.