Description

Komatsu PC27MR-2, PC30MR-2, PC35MR-2, PC40MR-2, PC50MR-2 2007 Workshop Manual

If you’re turning wrenches on a Komatsu mini-excavator from the MR-2 series, you need the factory book, not some aftermarket condensation. This isn’t a highlight reel. The Komatsu PC27MR-2, PC30MR-2, PC35MR-2, PC40MR-2, PC50MR-2 2007 Workshop Manual runs 630 pages and covers exactly what you’ll find under the hood and undercarriage. No shortcuts. No third-party reprints. You get the same binder that Komatsu dealers pull off the shelf.

Let me tell you what’s inside that matters on the bench. Section 01 (General) has the lubricant and coolant specs – that’s where you’ll find the correct engine oil viscosity for a San Antonio summer. Section 10 (Structure, Function and Maintenance Standard) dives into the cooling system, power train, hydraulic components, and the electric control system. Section 20 (Testing and Adjusting) – this is where the real meat lives. Valve clearance adjustment, fuel injection timing, PC valve adjustment, LS differential pressure. I’ve had techs try to fudge those numbers. You can’t. They’re in there for a reason.

Cooling System and Cylinder Head Coverage

The cooling section in this manual is not generic. It gives you the capacity, the flow direction, and the bleed procedure. For the engines – 3D82AE-5M on the PC27MR-2, 3D84E-5N on the PC30MR-2, S3D84E-5PBA and 3D88E-5P on the PC35MR-2, 4D88E-5X on the PC40 and PC50 – you get the valve clearance adjustment procedure. Page 20-7 in the adjusting section lays out the intake and exhaust clearance specs. If you skip that step and button it up, you’ll be chasing a miss that isn’t electrical. The cylinder head torque sequence is there too. Don’t guess the pattern – it’s a Komatsu, not a small-block Chevy.

Fuel System Diagnostics: Factory Procedure

The fuel injection timing test on page 20-11 is the kind of thing you’d pay a dealer $300 to diagnose. This manual walks you through the measuring engine speed, exhaust gas color check, compression pressure measurement, and fuel control lever adjustment. The standard value table for engine-related parts lists the allowable compression pressure range. I’ve seen guys throw fuel pumps at these machines when the injection timing was off a degree. Save yourself the parts cannon approach. Use the factory data.

Does This Manual Include Wiring Diagrams and Connector Locations?

Yes. The troubleshooting section (H-Mode and E-Mode) covers electrical system faults: E-1 engine won’t start, E-2 engine won’t stop, windshield wiper and travel alarm circuits. There’s a connector arrangement diagram, pin number connection table, and a T-adapter box table. If you’re chasing a no-start that isn’t fuel or compression, you’ll use the E-Mode troubleshooting charts. The point to remember when carrying out maintenance – it’s all there. No guesswork, just a sequence of events to follow.

Torque Specifications You Can Trust

I’ll say this about aftermarket manuals: they nearly always fail on torque values. One errant number and you’re leaking hydraulic fluid from a banjo bolt or stripping a carrier roller fastener. This Komats factory publication gives you the standard value tables for engine and chassis parts. Section 20 lists the specific torque for the swing holding brake release pressure test and the travel deviation adjustment. When you’re dealing with multiple control valves and PPC valves, torque matters. The oil pressure tests for work equipment, travel, boom swing, swing, and blade circuits – each has a pressure spec and a test port diagram. You won’t find that on an internet forum.

7 Systems Covered – One Binding

This manual covers: General specs, structure/function/maintenance, testing and adjusting, disassembly and assembly, and others. The major systems – engine, fuel, cooling, hydraulic, power train, swing, track frame. For the track frame, you get idler cushion adjustment, track shoe tension test, and sprocket inspection. The hydraulic components layout drawing is worth a thousand words. If you’re doing a center swivel joint rebuild or a travel motor overhaul, Section 30 has the disassembly procedure. You’ll also find the CLSS (Closed Loop Load Sensing) operation explanation. That’s not basic. That’s the kind of detail that separates a working rebuild from a paperweight.

Who Needs This Manual?

Anywhere you’ve got a MR-2 series machine in your fleet – rental yard, construction company, or home garage with a serious compact excavator. The manual applies to serial numbers PC27MR-2 15001 and up, PC30MR-2 20001 and up, PC35MR-2 5001 and up, PC40MR-2 8001 and up, PC50MR-2 5001 and up. If you’re a field technician working on these, you need the bleeding procedure for the hydraulic circuit and the residual pressure release steps. That part alone can save you from a face full of hot oil.

Source Authenticity: OEM vs Aftermarket

I’ve been burned by aftermarket manuals that reprint the wrong page numbers and skip the revision sheets. This is an official Komatsu shop manual, printed in Japan in 2007, with a revision mark index and a list of revised pages. You can see the revision numbers (11, 8, 9) on the page index. That means Komats updated the content and this document reflects the latest specs. No third-party condensation. This is the same document the factory engineers used to write the training materials. I don’t trust aftermarket documentation on principle. This is the real deal.

Q: What engine models are covered in this manual?

PC27MR-2 uses the 3D82AE-5M; PC30MR-2 uses the 3D84E-5N; PC35MR-2 uses S3D84E-5PBA and 3D88E-5P; PC40/50MR-2 uses the 4D88E-5X. For engine internals, you’ll need the separate 68E-88E Series Engine Shop Manual, but this workshop manual covers all on-machine tests and adjustments.

Q: Does it include torque specs for the cylinder head?

Yes. The valve clearance adjustment procedure in section 20 gives the specs. The cylinder head torque sequence is in the disassembly section. Use a factory torque chart – not a guess.

When you’re ordering gaskets, bearings, or hydraulic seals, pair this workshop manual with a Komatsu PC27MR-2 PC30MR-2 PC35MR-2 PC50MR-2 Parts Catalog so you have exploded views and part numbers. For a complete overhaul, consider the Komatsu PC27MR-2 PC30MR-2 PC35MR-2 PC40MR-2 PC50MR-2 Workshop Manual if you need the engine-specific supplement. For daily operation and maintenance intervals, get the Komatsu PC27MR-2 PC35MR-2 Operation Manual.

Comparing equipment? If you’re also working on heavy trucks, a Manual Transmission rebuild requires the same respect for factory spec. And if you’re dealing with older Manual Transmission units, the reasoning behind OEM documentation applies equally – torque is torque, and comebacks cost money.

Access the Factory Manual and keep a copy on your tablet or print the pages you need for the job. You’ll have the torque values, the test pressures, and the troubleshooting sequences without an internet connection. That’s how you get the job done right and get it done once.