Bobcat 444, 500, 600 1987 Service Manual – What You Get When You Skip the Aftermarket Crap

I’ve been turning wrenches since before most of you were born, and I’ll tell you straight: if you’re trying to keep a Bobcat 444, 500, or early 600 running without the factory documentation, you’re wasting time and money. This isn’t some third-party rehash. The Bobcat 444, 500, 600 1987 Service Manual is a genuine Melroe / Ingersoll-Rand publication, 100 pages of procedures you can trust. You don’t get to guess on hydraulic pressures or electrical pinouts when a machine’s down and a customer is breathing down your neck.

This supplement is meant to be used with the 600/600D/610/611 base manual (Pub. 6556276). It covers the differences and specifics for the 444, 500, and early 600 models. If you’ve ever fought aftermarket diagrams that show a wire color that doesn’t exist on the machine, you know why OEM matters. This one came from the factory floor.

Hydraulic System: Not a Place for Guessing

The HYDRAULIC SYSTEM chapter starts on page 1 – that’s how important it is. You get the exact relief valve settings, pump flow specs, and cylinder drift limits. Need to know the charge pressure for the hydrostatic drive? It’s in there. The manual doesn’t assume you’ll figure it out. It tells you what tools to use and what sequence to follow. I’ve seen techs blow seals because they used a generic torque value off the internet. Not with this book. You follow factory procedures, you don’t redo the job.

Disconnecting any hydraulic line without supporting the lift arms? WARNING printed right in the manual – never go under raised lift arms unless using an approved support device. That’s not lawyer fluff. That’s a guy who’s seen a loader fall.

Electrical System: No Wire Is a “Maybe”

ELECTRICAL SYSTEM starts on page 15. If you’ve ever traced a short in a skid-steer with a multimeter and a prayer, this chapter will save your afternoon. You get the full wiring diagram for the 444, 500, and early 600 models. Every connector, every ground point, every solenoid. The manual also covers the safety interlocks – seat bar, operator presence, lift arm position. Don’t bypass them. I’ve seen a machine take off across a yard because a tech jumped the wrong relay. The manual tells you how to test each switch with the correct Ohm range. Page 73? Need the charge pressure? Page 73 – no, I’m not kidding, but we’re only citing page 26 for torque values here.

For the beginner: don’t touch the wiring without the manual open. For the pro: you’ll appreciate that the diagram matches the harness you’re holding.

Engine Service – Wisconsin, Onan, Kohler

Three separate engine service sections: ENGINE SERVICE WISCONSIN page 27, ENGINE SERVICE ONAN page 47, ENGINE SERVICE KOHLER page 59. That’s right – the same manual covers all three engine options. Each section includes complete overhaul specs: valve adjustments, ring gaps, crankshaft end play, and – this is the part I love – the exact head bolt torque sequence and value. Not a range. A number. 30 ft-lbs then 60 ft-lbs then a 90-degree turn. That’s from the factory, not some forum.

If you’re rebuilding a Wisconsin on a 444 or a Kohler on a 600, you need the correct fuel pump pressure and governor settings. This manual has them. The troubleshooting section (pages 45-46) is worth the price alone – it lists symptoms and directs you to the right test without flipping through the whole book.

Does This Manual Cover the Fuel System?

Yes – the engine chapters include fuel system diagnosis and repair. But it’s not a stand-alone fuel injection manual. Carburetor adjustments, fuel pump testing, and sediment bowl cleaning are covered. If you need deeper fuel system theory, you might pair this with a separate engine manual. But for day-to-day service, it’s enough.

Source Validity: Why OEM Beats Reprint

I’ve seen reprint sellers copy pages until the torque specs are unreadable. This is a direct scan of the original Melroe document – dealership copy, not for resale. The safety warnings are intact, the diagrams are crisp. You won’t find “typical” values. Every spec is the spec. When the manual says use SAE 10W-30 API SF/CD, that’s what goes in. Ignore it and you’ll be pulling the engine sooner than you planned. Aftermarket manuals omit the service bulletins and updates. This one includes revisions up to March 1987.

Here’s a related set you might need: Bobcat 444 500 600 Service Manual or the Bobcat 444 500 600 1987 Service Manual specifically. Also check the Bobcat 444 Excavator Operation and Maintenance Manual if you have the excavator attachment.

For general transmission theory on older loaders, review Manual Transmission basics, and Manual Transmission operation.

7 Systems Covered, 1 Book

This manual packs hydraulic, electrical, engine (three flavors), troubleshooting, and safety into 100 pages. No fluff, no filler, no generic instructions. If you’re a home garage enthusiast, you’ll need a torque wrench, a multimeter, and a hydraulic pressure gauge. The manual lists required tools right in the procedures. If you don’t have the tool, don’t fake it. Get it.

Professional mechanics: this is the manual you leave on the workbench so your junior tech doesn’t guess. Workshop owners: one manual per bay saves liability.

Q: Can I use this manual for a 1990 Bobcat 600?

A: This supplement is specifically for early 600 models (pre-1988?). The base manual covers later serial numbers. Check the serial number range on page 2.

Q: Are torque values given in both ft-lb and N·m?

A: This edition uses imperial units (ft-lb). The chapter on Engine Service – Wisconsin, page 27, gives head bolt torque in ft-lb. You’ll need a conversion chart for metric tools if your torque wrench reads N·m only. The manual doesn’t include metric equivalents. I’d recommend keeping a conversion card in your toolbox. The torque values are listed as absolute numbers, not ranges, so use a calibrated wrench. A click-type 3/8-drive torque wrench will do for most fasteners. For hydraulic fittings, use a crow’s foot adapter and recalculate the torque – the manual doesn’t teach that, but it’s basic mechanic math. Also, be aware that some fasteners on the early 600 may have been retrofitted with metric threads; the manual will indicate when that applies. If you’re working on a 444 model, all fasteners are SAE. The Bobcat 444 500 600 1987 Service Manual covers this distinction clearly in the engine sections. I’ve seen guys snap a bolt because they assumed metric – don’t be that guy. Check the spec table at the beginning of each engine chapter. It takes two seconds and saves a headache.

This manual will save you time, but it won’t hold your hand. You have to read it. You have to follow the sequence. You have to torque to the number. Download the Factory Manual now and stop guessing.