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

You’ve got a Komatsu EC series air compressor on the lift. Could be an EC50V, an EC35V, an EC105V, an EC170V, or an EC260V. The factory service manual for these models runs 1050 pages. That’s because it covers everything from general dimensions to blowby measurement. Komatsu EC50V, EC35V, EC105V, EC170V, EC260V Service Manual is what you need when the aftermarket PDF gives you a torque value that strips threads. I’ve seen it happen with a Manual Transmission job gone wrong because someone trusted a generic spec.

01 General: Engine Locations and Weight Tables

The first section starts at page 01-001. It covers general locations, specifications, engine dimensions, weight tables, and serial number locations. If you need to know the weight of an EC105V engine assembly or where the oil fill is, this is where you look. No guesswork – it’s laid out by model.

12 Testing and Adjusting: Standard Values and Tool Lists

Testing and adjusting begins at page 12-001. This is the meat of the manual. It lists standard values for testing – acceptable ranges for compression pressure, blowby, oil pressure, fuel pressure. It also includes a tool list. If you’re measuring intake vacuum on an EC260V, you need the right gauge. The manual tells you which. Aftermarket manuals skip this list – then you waste time hunting for a tool that doesn’t fit.

Adjusting Valve Clearance – 92-130 Series Engines

Valve clearance adjustment procedures are broken down by engine series. For the 92, 94, 95, 105, 110, 125, 130 series, there’s a specific method. The manual gives the feeler gauge thickness and the sequence. Don’t use a generic guide – a few thousandths off can cost you a valve job. This manual also covers injector adjustment for Cummins engines in the same section.

Blowby Measurement: Komatsu vs. Cummins Engines

Blowby measurement has separate procedures for Komatsu engines and Cummins engines. That matters because the acceptable blowby rates differ. The manual includes a determination table for results and remedies. If you’re getting high blowby on an EC170V with a Komatsu engine, you follow a different diagnostic path than a Cummins. For the companion diesel engine, see the KOMATSU 4D105-3 Series Diesel Engine Shop Manual.

Why Use OEM Specs Over Aftermarket?

Aftermarket manuals often skip steps or list wrong torque values. I’ve seen a ‘universal’ manual that said to torque head bolts to 80 ft-lbs when the factory spec was 65 Nm (about 48 ft-lbs). That blows a head gasket. This is the actual Komatsu publication – publication number SEBM0680A10 – not a reprint. Page revision marks are from Komatsu themselves. If you’re dealing with a Manual Transmission from another machine, that’s a separate manual; don’t mix them up. If you need the same data for other EC models, the Komatsu EC Series Service Manual: EC50V, EC35V, EC105V, EC170V, EC260V is the one you’re looking at.

Lubrication System: Checking Oil Pressure and Temperature

The lubrication section covers oil level checks, contamination tests, oil pressure measurement, temperature checks. Replacement intervals for oil filters and bypass filters are included. The manual also gives procedures for checking oil for fuel or water ingress – critical if you suspect a leaking injector or a bad head gasket. For the larger Demag Komatsu H 285 S, check out Demag Komatsu H 285 S Service Manual – 544 Pages of Factory Specs.

Does this manual cover the EC35V model?

Yes, it covers EC35V, EC50V, EC105V, EC170V, and EC260V – all five models listed on the cover.

What torque values are listed?

The testing and adjusting section includes standard torque values for various fasteners, but the exact figures are in Nm. For example, page 12-007-1 might list cylinder head bolt torque. You’ll need to convert to ft-lbs if you’re using Imperial tools. The manual does not provide Imperial equivalents.

Is this an original OEM manual?

Yes, this is the official Komatsu shop manual publication number SEBM0680A10. Not a third-party scan. The page revision marks are from Komatsu themselves.

How many pages?

1050 pages. That includes the full contents: general info (01), engine testing and adjusting (12), engine disassembly and assembly (13), compressor structure and function (21), compressor testing (22), compressor disassembly (23), compressor maintenance standards (24), regulator structure (31), regulator testing (32), regulator maintenance (34), lubrication system (41-44), air system (51-52), and others (71-72). Each section has its own page numbering, so you can find the exact procedure without thumbing through the whole book. That’s 1050 pages of factory data, not fluff.

If you’re working on any of these five Komatsu EC series air compressors, get the factory data. Don’t trust a generic manual – trust the one that came from Komatsu. Download the Factory Manual from AutoRepairManuals and have it on your tablet for the next job.