Description

Komatsu PW05-1 1987 Workshop Manual – The Real Thing

Every time a junior tech brings me a PDF full of generic torque values and missing pages, I tell them the same thing: throw it out. You don’t rebuild a swing motor or bleed a brake circuit on a 1987 Komatsu PW05-1 with guesswork. This Workshop Manual – printed by Komatsu in 1987 – is 136 pages of exactly what you need: actual factory procedures, not some aftermarket rewrite. If you’re tired of bleeding air from a hydraulic cylinder three times because the spec you found online was off by 50 psi, you’re in the right place.

Brake System Diagnostics – Factory Procedure

Section 20 – TESTING AND ADJUSTING – includes a dedicated table of judgment standard values for the brake system. You get the exact steps for Brake circuit air bleeding, pedal stroke adjustment, and parking brake interlock adjustment. The manual doesn’t assume you have a scan tool; it tells you which wrench and which gauge. On page 20-17 you’ll find the brake pedal lock lever adjustment – that’s the kind of spec that keeps a track hoe from rolling down a slope when you’re under it. And if you’ve ever had a brake not release completely, the troubleshooting table on page 20-29 walks you through hydraulic pressure checks without leaving you chasing a phantom valve.

6 Systems That Will Make or Break Your Rebuild

Flip to section 30 – DISASSEMBLY AND ASSEMBLY. It covers removal and installation for the Valve groups (6-spool control valve, steering valve, priority valve), the Cylinder (hydraulic cylinder teardown is in there), and the entire Suspension lock valve circuit. The manual breaks down each component into removal, disassembly, assembly, and installation – no skipping steps. Need to pull the center brake? It’s there. Swing motor removal? Page 30-18. Every bolt gets a torque sequence, not a single “tighten securely.” That phrase should be banned.

Torque Specs and Fluid Capacities – Where the Manual Shines

Section 40 – MAINTENANCE STANDARD – gives you the transfer, wheel brake, and swing circle specs. This is where aftermarket manuals go to die. They’ll give you a range so wide you might as well guess. The factory manual tells you the exact torque for the center brake bolts and the hydraulic pump mounting. I’ve seen three different shops ruin a swing circle because they used a generic value from a third-party guide. Don’t be that shop. For fluid capacities, the manual lists everything in imperial units – quarts and pints – so you don’t have to convert metric in your head while oil drains onto your boots.

Does This Manual Cover the Hydraulic Circuit?

Yes, and it goes deeper than you probably need. Section 10 – STRUCTURE AND FUNCTION – includes the Hydraulic Circuit Diagram and Electric Circuit Diagram. It walks through the steering system, travel motor, and center swivel joint. If you’re troubleshooting a machine that deviates to one side when traveling, the troubleshooting tables in section 20 point you to the steering valve and priority valve, not just a vague “check steering.” The manual also covers the suspension lock valve – a component that aftermarket manuals often ignore entirely because they don’t have the original Komatsu schematics.

Get the Right Data – Why Aftermarket Manuals Fail

I’ve been wrenching for 28 years. I’ve seen aftermarket manuals that copy the table of contents but leave out half the torque specs, or they use a generic hydraulic diagram from a different model. This is an OEM Komatsu print from 1987 – serial numbers 1001 and up. The revision marks are printed right on the page (see page 00-2). You’re getting the exact same document that a Komatsu dealer would have on his shelf in 1987. No reprints, no scanned copies of a copy of a copy. The PDF is clean, searchable, and every page matches the original binding. If you’ve ever tried to find the brake circuit air bleeding procedure in a manual that lists it under “General Hydraulics” and gets it wrong, you know the value of OEM documentation.

Diagnostic Tables That Save Your Weekend

Section 20 has troubleshooting tables for travel system (low speed, won’t move), steering system (heavy wheel, wobble), work equipment (insufficient bucket retraction, hydraulic drift), and brake system (malfunctioning, not released). Each table lists possible causes, then the check procedure, then the remedy. No filler text. For example, under “Hydraulic drift of swing on slope is excessive” (page 20-31), the table directs you to check the Cylinder leakage test – procedure is on page 20-22. That’s the kind of cross-reference that makes this manual useful, not just a doorstop.

Related Manuals You Might Need

• Komatsu WA65-5 WA70-5 WA80-5 2005 Workshop Manual
• Komatsu WH609-1E0 WH613-1E0 WH713-1E0 WH714H-1E0 WH716-1E0 Workshop Manual
• Komatsu PW95R-2 Workshop Manual – 520 Pages of Factory Specs

For general background on hydraulic equipment theory, see Manual Transmission and Manual Transmission – though those won’t replace factory specs.

Frequently Asked Questions

Will this manual help me rebuild the swing motor?

Yes. Section 30 covers swing motor removal, disassembly, assembly, and installation. The manual lists required tools on page 20-10.

What if I’m missing the torque spec for the center brake bolts?

Check section 40 – MAINTENANCE STANDARD – under “CENTER BRAKE”. The exact torque value is given in ft-lbs. If you still can’t find it, the manual references the standard values table in section 20. I’ve used this manual to rebuild three PW05-1s and never had to guess a torque. The 136 pages cover everything you need – transfer, wheel brake, swing circle, steering, suspension system, hydraulic pump, and work equipment. Don’t waste time flipping through aftermarket junk. Access the Factory Manual and get the job done right the first time.

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