Description

Komatsu EC50V, EC35V, EC105V, EC170V, EC260V Service Manual – 1050 Pages of Factory Specs

You’ve got a Komatsu EC series air compressor that’s down. Maybe it’s blowing oil, losing pressure, or the engine won’t crank. Without the factory data, you’re guessing. Guessing costs time and parts. This Komatsu EC50V, EC35V, EC105V, EC170V, EC260V Service Manual is the exact 1050-page document Komatsu dealers use. It’s not a condensed reprint or a third-party summary. It’s the OEM manual with part number SEBM0680A10, including revision marks and page change history. If you’ve ever had an aftermarket manual tell you “torque to spec” without giving the number, you know why this matters.

Engine Testing and Adjusting: What You Get

Section 10 of this manual covers the engine in depth. That’s the 12 TESTING AND ADJUSTING chapter. You get standard values for testing and adjusting – not generic numbers, but Komatsu’s own limits. The manual lists the exact tools you need for each procedure. Measuring engine speed? There are three methods: mechanical service meter, electric service meter, and piezo-electric tachometer. Cranking the engine? Two methods: barring and cranking kit. Intake and exhaust system checks include cleaning the precleaner, air cleaner, intake pipe, and turbocharger. Valve clearance adjustments are covered for 92, 94, 95, 105, 110, 125, 130 series engines and the 3D94, 95 series. If you’re working on a Cummins engine in the EC series, injector adjustment and valve clearance are in there too. Blowby measurement procedures are separate for Komatsu and Cummins engines, with diagnostic criteria. Compression pressure measurement includes precautions and result interpretation. The manual even tells you when to clean the piston cooling nozzle and breather element. You’ll find the standard values table on page 12-001, and the blowby measurement section starts around page 12-201. That level of detail saves you from making assumptions.

7 Major Sections – From General to Air System

The table of contents splits the manual into seven clean categories:

• 01 GENERAL – specifications, engine dimensions, weight tables, fluid fill points
• 10 ENGINE – testing, adjusting, disassembly, assembly (the biggest section)
• 20 COMPRESSOR – structure, function, testing, adjustment, maintenance standards
• 30 REGULATOR – same coverage for the pressure regulator
• 40 LUBRICATION SYSTEM – oil system checks, replacement, consumption measurement
• 50 AIR SYSTEM – air system structure, testing, adjustment
• 70 OTHERS – miscellaneous structure and function, testing

Each section follows the same logical flow: structure and function first, then testing and adjusting, then disassembly if applicable, and finally maintenance standard. That means you can find the information you need without flipping through 500 pages of irrelevant data.

Understanding the EC Series: EC50V, EC35V, EC105V, EC170V, EC260V

This manual covers five V-series models: EC35V, EC50V, EC105V, EC170V, and EC260V. It also covers the Z-series variants (EC25Z, EC35Z, etc.) but the primary focus for this manual is on the V models. Serial numbers start at 1001 for each – check your machine plate. The manual includes engine locations, general dimensions, and a weight table specific to each model. If you’re swapping a power unit or confirming frame specs, those details are in the GENERAL section. The EC series are rotary screw air compressors, not piston types, so the compressor section (20) is a key part of the manual. Don’t confuse them with smaller home shop units – these are industrial machines.

Get the Right Torque Data – OEM Only

Aftermarket manuals often quote “tighten securely” or “refer to manufacturer” – which is useless on the bench. This manual gives you factory torque specs for every critical fastener on the engine and compressor. The lubrication system section lists oil pressure and temperature ranges. The fuel system sections (both Komatsu and Cummins) include injection pump delivery checks and injector spray testing. Valve clearance specs are given for each engine series. You get the original Komatsu revision marks and page update history – that’s how you know the data hasn’t been altered. The manual even includes a list of revised pages with revision numbers, so you can verify you’re working with the current version. For real-world use, that means you can torque a connecting rod bolt to the number Komatsu engineers specified, not some rounded-off estimate.

Does This Manual Cover the Regulator and Air System?

Yes. Sections 30 and 50 are dedicated to the regulator and air system respectively. For the regulator, you get structure and function (31), testing and adjusting (32), and maintenance standard (34). The air system section covers structure and function (51) and testing and adjusting (52). If your compressor is cycling too fast or not building pressure, these chapters will walk you through the diagnostic steps. The manual doesn’t skip the small stuff – it includes checking operation of cut-off valves, vacuum pressure tests, and fuel system air bleed procedures. You won’t need to cross-reference with a separate hydraulic manual; everything is integrated.

This manual is the same one that sits in Komatsu dealer service bays. It’s printed on factory-original sheets – not a photocopy or a scanned OCR mess. The 1050-page count means nothing has been abridged. For technicians who rely on verified specs, this is the only source that should be on your bench.

Who Needs This Manual?

If you own or maintain a Komatsu EC35V, EC50V, EC105V, EC170V, or EC260V air compressor, you need this manual. It’s also useful for fleet shops that service multiple EC-series units. Beginners can follow the step-by-step procedures, but you’ll need basic mechanical skills and the listed tools. The manual doesn’t assume you’re a Komatsu specialist – it starts with general locations and specifications before moving into testing. That said, if you’ve never adjusted an injector, read the valve clearance section twice before touching the engine. For those who want to understand how the compressor interacts with the drivetrain, external resources like Manual Transmission knowledge can help, but this manual stays focused on the air compressors and their engines. Another good companion is the Manual Transmission guide for the vehicle that carries the compressor, though the EC series are typically standalone units.

Do I need special tools to use this manual?

Yes. The manual includes a tool list for each testing procedure – you’ll need them to get accurate results. No shortcuts.

How do I know this is a genuine factory manual?

The manual carries Komatsu part number SEBM0680A10 and includes a list of revised pages with revision dates and marks. Page 00-1 shows the machine model and serial number range exactly as Komatsu publishes them. The page numbering follows the factory standard (01-001, 12-003, etc.) and matches what dealers use. Aftermarket copies often omit the revision history or condense multiple procedures – this manual has every page, including revision marks like the bullet and open circle symbols indicating new or replaced pages. That level of detail proves it’s an original OEM document, not a reprint.

You’ve read the reasons. Now stop guessing on your EC series compressor. Access the Factory Manual and get the same data Komatsu technicians rely on. Your machine – and your wallet – will thank you.

Related manuals you might need: KOMATSU 4D105-3 Series Diesel Engine Shop Manual for engine-specific rebuilds, Komatsu EC Series Shop Manual if you need the complete set, or Demag Komatsu H 285 S Service Manual – 544 Pages of Factory Specs for larger models.