Description

Komatsu HD325-5 Workshop Manual – Factory Specs for Heavy Equipment

I’ve been wrenching on heavy equipment for 28 years, and I can tell you the difference between a job that goes smooth and one that turns into a parts cannon is the manual you’re leaning on. Aftermarket reprints? They’ll leave you guessing on valve lash, torque converter pressure, and fuel injection timing. That’s billable time down the drain—or worse, a dropped valve. The Komatsu HD325-5 Workshop Manual is the factory-issued book for these dump trucks, serial numbers 2001 and up. It’s 718 pages of the actual procedures Komatsu wrote, not some third-party rewrite that skips the critical steps.

718 Pages of Factory Procedures

This isn’t a condensed guide. The manual breaks down every major system into testing, adjusting, disassembly, and assembly sections. Page 12-1 starts the engine testing chapter with a standard value table for compression pressure, blow-by, and oil temperature. You get the actual numbers Komatsu used on the line—none of that “tighten until snug” nonsense. If you’re rebuilding a SA6D140-1 engine, you need those numbers. The manual also lists required tools for each job. No more digging through drawers wondering if you have the right adapter for the injector timing light.

What the Engine Section Covers

The engine section (chapter 10) covers testing and adjusting first, then disassembly and assembly. You’ll find procedures for adjusting valve clearance, measuring compression pressure, and timing the fuel injection pump. Blow-by pressure measurement is included—critical for detecting ring wear before you pull the head. The manual also details air bleeding from the fuel system, which is a common frustration with these trucks after a filter change. Follow the order in section 12 and you won’t end up cranking a dry injection pump. Need to swap the nozzle holder? Section 13 walks through removal and installation with torque values for the hold-down bolts.

Valve Clearance and Fuel Timing – Why Specs Matter

I’ve watched guys set valve lash by feel and then wonder why the exhaust gas color is off. The HD325-5 uses a six-cylinder SA6D140-1 diesel, and the clearance spec changes with engine temperature. Section 12 lists the cold and hot adjustment procedures. Same for fuel injection timing—the manual gives you the static timing mark alignment and the dynamic angle check. Skip that step and you’ll be pulling the injection pump again. The “ADJUSTING FUEL INJECTION TIMING” procedure in section 12 is one of those pages you’ll tab and come back to every time you service a pump.

Power Train Diagnostics – Test the Torque Converter

The power train section (chapter 20) is massive—structure, function, testing, and maintenance for the torque converter, transmission, axles, and brakes. You get a hydraulic circuit diagram for the power train oil system, which is essential when diagnosing a transmission that slips under load. Page 22-1 lists the judgment standards for torque converter oil pressure and transmission clutch circuit pressure. I’ve used those numbers to catch a worn modulation valve before it took out a clutch pack. The manual also covers how to adjust the manual shift console and measure shift lever operating force. If you’re dealing with a hard shift or no shift, start there.

Source Authenticity – OEM vs Aftermarket

The copy you get from AutoRepairManuals is a direct scan of the original Komatsu shop manual, not a retyped PDF with missing tables. It includes the full list of revised pages (see page 00-01) and the machine model serial number range. Aftermarket manuals I’ve seen omit the torque converter stall test procedure or give generic oil pressure ranges that don’t match what Komatsu designed. This one has the official “SEBM05660510” part number on the cover. If you’re rebuilding a differential or setting up the final drive (planetary carrier removal in section 23), you want the factory clearance specs, not a guess.

FAQ

Does this manual cover the automatic transmission adjustment?

Yes, section 22 includes testing and adjusting of accelerator pedal for automatic transmission, measuring transmission shift lever operating force, and adjusting clutch circuit oil pressure.

What about the brake system?

Front and rear brake testing, bleeding, and disc wear measurement are in section 22 and 23. Also covers parking brake adjustment.

You’ve got the truck in the bay, the parts on the bench, and the clock running. Don’t waste time flipping through a generic manual that leaves out the torque values for the cylinder head bolts or the correct method to bleed the fuel system. Get the factory data on your screen or printed out. Related manuals you might need: Komatsu HD325-5 Workshop Manual – OEM Factory Specs & Procedures, Komatsu WA65-5 WA70-5 WA80-5 2005 Workshop Manual, and Komatsu WH609-1E0 WH613-1E0 WH713-1E0 WH714H-1E0 WH716-1E0 Workshop Manual. For background on transmission types, read about Manual Transmission and Manual Transmission. Access the Factory Manual and keep it on your bench—it’s the difference between a fix and a redo.