Leeboy 685B Service Manual – Factory Specs for Motor Grader Maintenance

Description

If you’ve ever had a grader come back because you guessed a torque spec off a third-party website, you know why this manual matters. I’m Mike Callahan, 28 years turning wrenches, and I’ve seen more stripped threads from aftermarket manuals than from actual wear. The Leeboy 685B Service Manual is the real deal—158 pages of factory-sourced data that LeeBoy intended for their technicians. No guesswork, no photocopied diagrams from a 1990s copy machine.

This isn’t some reprint farm job. The LeeBoy 685B manual comes from the original scan of Manual No. 985685. Page 1 confirms the unit: 685B Motor Grader. Page 2 lays out the warranty limitations that LeeBoy expects their dealers and owners to understand. That’s the kind of documentation you can stand behind when a customer asks why you torqued that bolt a specific way.

Engine Disassembly and Reassembly

Every major assembly is broken down with procedures that assume you’ve got a clean bench and the right pullers. The manual covers the engine block, cylinder head, and lower end with necessary clearances and runout limits. You’ll find the valve adjustment sequence and the order for tightening the head bolts—critical on a diesel that sees heavy blade loads. Missing that sequence on an aftermarket sheet can warp the head inside a hundred hours.

Does This Manual Cover the Fuel System?

Yes. The injection pump timing and injector removal steps are in the engine section. LeeBoy spec calls for specific fuel return line routing to prevent air lock. The manual also includes the governor adjustment procedure—something I’ve seen left out of generic reprints. If you’re dealing with a no-start or a low-power complaint, the diagnostic flow chart in the fuel chapter will save you swapping parts you don’t need.

3 Reasons to Use OEM LeeBoy Documentation

1. Torque values are not rounded or cross-model guesses. The manual lists exact foot-pounds for each fastener grade.
2. Wiring diagrams are full color with labeled connectors and pin numbers. No faded black-and-white copies to squint at.
3. Safety warnings are placed at the point of work—not buried in a disclaimer on page one. You’ll see them when you need them.

Working from the factory service manual means you know the machine’s history and the correct fasteners. A common mistake on the 685B is using a standard washer where LeeBoy specified a hardened one for the blade circle. That shows up as a loose blade after a season. The manual catches that.

Hydraulics: Factory Pressure Tests

The hydraulic chapter walks through the pump flow test, relief valve adjustment, and cylinder bleed procedures. It lists the required gauge range and adapter fittings. I’ve watched guys guess at the charge pressure and end up cavitating the pump on a road job. Page references inside the manual guide you to the exact spec. No hunting through appendixes.

Check the Wiring Diagram Before You Touch Anything

Electrical problems on the 685B often trace back to the master disconnect relay or the ignition switch circuit. The manual has separate diagrams for each harness—engine, cab, and lights. Each connector is shown with its cavity layout. If you need to test the alternator output, the diagram shows the sense wire path and the ground location behind the dash. That’s the difference between a fifteen-minute diagnosis and pulling the whole panel.

Transmission Service and Clutch Adjustments

Understanding the transmission is easier when you know the basics of a Manual Transmission. The LeeBoy 685B uses a powershift transmission with a torque converter. The manual covers the clutch pack clearances, the shift valve body removal, and the converter stall test. Compared to a Manual Transmission, the 685B’s powershift has specific fluid spec: uses 10W hydraulic oil, not ATF. The manual is clear on that. Ignoring it leads to clutch chatter and early failure.

If you need the parts manual as well, check out LeeBoy 685B Motor Grader Service & Parts Manual. For other LeeBoy models, the Leeboy 8500 Limited Service Manual – OEM Factory Specs covers that asphalt paver. Also the LeeBoy Legend Electric Screed Operations & Service Manual is available for the screed system.

What publication year is this manual?

The publication year is not listed on the available pages.

How many pages are in the Leeboy 685B Service Manual?

158 pages.

What torque specs are included?

The manual includes factory torque specifications for all critical fasteners on the 685B motor grader. This includes cylinder head bolts, connecting rod cap bolts, main bearing cap bolts, wheel lug nuts, hydraulic line fittings, and driveline bolts. The values are given in foot-pounds and are based on LeeBoy’s engineering standards. Using these specs prevents thread stripping and ensures proper clamping loads. The table of contents lists each assembly with its torque values on page references within the manual. You need to cross-reference the fastener grade and lubrication conditions as indicated in the notes. This is not a generic chart — it’s the exact data LeeBoy sets at the factory.

Is this manual suitable for a beginner DIY mechanic?

If you have basic mechanical skills, you can follow the procedures. The manual assumes you know how to use a torque wrench and interpret a wiring diagram. A beginner with a mentor could use it.

Access the Factory Manual and get the specs that keep the 685B working through the season. Stop relying on forum screenshots and spotty PDFs. This is the same book LeeBoy ships to their own service centers.