Description

Hitachi Sumitomo EX300, EX300LC Operators Manual – Factory Specs for Hydraulic Excavator Operation

I’ll say it straight: I’ve seen too many operators dig into a machine with a photocopied third-party manual and then wonder why the track tension is off or why the hydraulic pressure doesn’t match. That’s not how you keep an excavator running for 20,000 hours. You need the factory document—the one Hitachi Sumitomo wrote for the EX300 and EX300LC. This Operators Manual is 144 pages of OEM truth, from page 3’s TO THE READER through the final optional attachment section. No aftermarket guesswork. Just the numbers Hitachi put on the line.

Safety and Controls – What the OEM Manual Covers

The first real section is SAFETY on page 3. If you think you can skip that because you’ve been around equipment, you’re fooling yourself. That chapter spells out the hazards specific to this machine—hydraulic accumulators, swing radius, track pinch points. Right after that comes CONTROLS AND INSTRUMENTS starting on page 5. You get every lever, gauge, and indicator explained with factory illustrations. I’ve watched guys burn up a swing motor because they didn’t know the neutral position indicator. That’s what this section prevents.

Does This Manual Cover the Fuel System?

Yes, and it does it properly. Under MAINTENANCE, the Fuel System section (letter E) gives you the OEM procedure for bleeding, filter replacement intervals, and fuel tank cleaning. It’s on page 83 of the 144-page document. No generic “drain and refill” advice—Hitachi tells you what grade of fuel, what viscosity at what temp, and how to purge air after a filter change. That’s the kind of detail a home garage guy or a shop foreman needs to avoid a stalled engine on a jobsite.

144 Pages of Factory-Authorized Content

This isn’t a condensed quickstart. It’s the full OPERATION manual split into three parts. PART ONE runs TO THE OPERATOR through TRANSPORTING. PART TWO is TO THE MECHANIC and dealer service personnel—that’s 80 pages covering everything from greasing (page 64) to engine oil changes (page 67), gear oil (page 70), hydraulic system (page 74), cooling system (page 87), and the electrical circuit diagrams on page 57. PART THREE handles optional attachments like thumbs and shears. Every section follows the same format: required tools listed upfront, step-by-step procedure, and a warning box if there’s a safety risk. No fluff, no reprints.

Maintenance Procedures – Greasing, Engine Oil, Hydraulic System

If you’re the guy doing the PM, turn to the MAINTENANCE section starting on page 61. The MAINTENANCE GUIDE (page 62) gives you a schedule. Then letter A—GREASING on page 64. It specifies which grease gun, how many shots, and which zerk fittings take 2–3 pumps versus a full 10. Letter B—ENGINE OIL on page 67 includes the API classification and SAE viscosity for your climate. Letter D—HYDRAULIC SYSTEM on page 74 covers filter change intervals, oil sampling points, and the correct hydraulic oil type. Listen: skipping the oil sampling step is how you end up with a failed pump. The manual tells you to take a sample at 500 hours. That’s not optional.

PART TWO: What the Mechanic Section Covers

This is where the manual earns its keep for a shop. Starting on page 45, the TO THE MECHANIC section repeats safety warnings specific to service work—high-pressure oil, spring-loaded accumulators, electrical shorts. Then COMPONENT LOCATIONS AND CIRCUITS on page 51 shows you where every valve and sensor sits on the EX300/EX300LC frame. The HYDRAULIC SYSTEM chapter (page 53) diagrams the main pump, control valves, and swing motor with line pressures. The ELECTRICAL CIRCUIT (page 57) has wiring diagrams for the start system and monitor panel. Need to troubleshoot an electrical issue? Turn to TROUBLESHOOTING on page 117. That section lists symptoms like “engine cranks but no start” and gives you the specific test points at the starter relay and fuel solenoid. It’s not a reprint of a generic manual—it’s machine-specific diagnostics.

If you’re looking for other Hitachi Sumitomo factory manuals, check the Hitachi Sumitomo ZX200 Operators Manual 2001 295 Pages for a later model. For bigger crawlers, see the Hitachi Sumitomo SCX1200-2 Operators Manual – Factory Specs & Safety and the Hitachi Sumitomo SCX1200-2 Operators Manual – Factory Specs for Hydraulic Crawle. All OEM, all direct from the source.

One more thing: if you’re new to tracked equipment and need to understand how a Manual Transmission works at a basic level, that’s valid background for the final drives on these machines. For deeper gear theory, you can also read up on Manual Transmission for general education. But for the EX300, you don’t need outside info—the manual gives you the final drive oil specs and drain intervals on page 70.

Frequently Asked Questions

Is this the same as the service repair manual?

No. This is the OPERATORS manual. It covers safe operation, daily inspection, routine maintenance, and basic troubleshooting (page 117). It does not include engine rebuild specs or track overhaul procedures. For full repair, you need the Factory Service Manual.

Does it include wiring diagrams?

Yes. The ELECTRICAL CIRCUIT section starting on page 57 has schematic diagrams for the start system, charging system, and monitor panel.

What hydraulic pressure specs are listed?

Specifications on page 127 list pilot pressure, main relief pressure, and swing brake release pressure. The manual does not give torque values for hydraulic fittings—that’s in the service manual.

Can I use this on an EX350?

No. This manual is serialized for EX300 and EX300LC from serial number 2386. Different displacement pump settings and undercarriage. Use the matching manual for your model.

Bottom line: if you want to operate your EX300 or EX300LC without guessing—and without paying the price of a blown O-ring or a misadjusted track—get the OEM document on your workbench. Access the Factory Manual now.