Description

FIAT Kobelco SK 100, SK 120, SK 120LC Workshop Manual

If you are working on a FIAT Kobelco SK 100, SK 120, or SK 120LC hydraulic excavator, the difference between a job that goes smooth and one that eats your billable hours is the manual you are using. Aftermarket PDFs that promise “universal coverage” will leave you chasing wrong torque specs and guessing on hydraulic pressures. This Workshop Manual is the factory OEM document – 810 pages, straight from Kobelco. I have seen what happens when a tech relies on a third-party reprint: stripped threads, blown seals, and a machine that comes back on the hook. Do not be that guy. Get the real thing.

LP12 Hydraulic System: Why Factory Specs Matter

The hydraulic chapter (section LP12 in the SYSTEMS portion) gives you the exact test pressures, flow rates, and relief valve settings for the SK 100, SK 120, and SK 120LC. Pretty much every hydraulic issue on these machines – weak digging force, slow swing, drifting attachments – traces back to pressures that are a few hundred psi off the factory spec. You will find the charge pressure right there on page 1 of the specification section. If you are rebuilding a hydraulic pump or a control valve, the COMPONENTS part (Hydraulic Pump section 12, Control Valve section 13) lays out the disassembly sequence and the wear limits for every bushing and piston. Do not skip the test procedure in LP04 – it tells you exactly how to measure clearance without guessing.

LP25 Electrical System: Avoid Short Circuits

The electrical system (section LP25) covers the entire harness routing, relay locations, and connector pinouts for the SK 100, SK 120, and SK 120LC. I have seen guys probe wires with a test light and fry a controller because they did not know which circuit had battery voltage key-on versus key-off. This manual includes the factory wiring diagrams – not redrawn, not simplified, the real thing. If you are chasing a no-crank condition or an intermittent warning light, start with the troubleshooting table in LP05. It walks you through a logical sequence that eliminates the guesswork. Want to know if a solenoid is getting power? The electrical schematics show the exact terminal numbers and wire colors.

LP05 Troubleshooting: Diagnose Without Guessing

Section LP05 is the troubleshooting chapter. It is organized by symptom: engine won’t start, boom drifts, tracks pull to one side. Each symptom has a decision tree that lists possible causes in order of likelihood. I have used this chapter on a SK 120 that lost travel power on one side. Five minutes of following the chart pointed me to a stuck relief valve in the travel motor – not a bad pump, not a failed control valve. A generic manual would have had me swapping parts. This one saved me four hours and a $2,000 pump purchase. The troubleshooting is written for a mechanic who knows his tools, not for a beginner who needs his hand held. If you are new to excavators, pair this with the Operator’s Manual for basic safety and operation.

COMPONENTS Section: Hydraulic Pump and Control Valve Overhaul

The COMPONENTS section of this manual (sections 12 through 21) gives you the breakdown for every major part: hydraulic pump, control valve, other valves, hydraulic motor, swivel joint, hydraulic cylinder, and reduction unit. Each component gets its own disassembly, inspection, and reassembly procedure with the OEM torque values for every bolt. Need to know the torque for the pump mounting bolts? It is in the specification table at the front of the component. I will tell you this: the cylinder disassembly procedure (section 17) shows you how to safely remove the piston rod and check the seal clearances. Do not try to guess – the tolerances are tight, and a .005-inch error can cause a leak that costs you days of downtime.

Source Validity: OEM vs Aftermarket

This manual is a genuine Kobelco factory print. I have seen aftermarket versions that copy the pages but miss critical updates – like a revised torque spec for the swivel joint bolts that Kobelco issued in a later service bulletin. The OEM document you are looking at includes all updates through the publication date. If you buy a reprint, you are buying risk. The safety warnings on page 2 of this manual are not optional – they remind you about lifting heavy components, wearing protective gear, and reading all warning plates before you start. I always tell my junior techs: the manual is your insurance. This one is worth every dime. Need a related manual for a different model? Check the KOBELCO SK 100 Shop Manual or the KOBELCO SK100 SK120 SK120LC Shop Manual for specific model variants. For a larger machine, look at the FIAT Kobelco SK330NLC-6E SK330LC-6E Workshop Manual – 1244-Page OEM. For general fundamentals on driveline components, read about Manual Transmission theory – but for this excavator, stick with the factory document.

FAQ

Does this manual cover the SK 120LC with extended tracks?

Yes. The SK 120LC is listed in the model name and the specifications section differentiates between the standard and long-track versions. Weights and dimensions for the LC variant are listed in LP01. You will also find separate hydraulic flow rates for the LC’s wider undercarriage.

Can I use this for the SK 100 with a cab versus canopy?

Both configurations are covered in the electrical and control system sections. The wiring diagrams show the cab and canopy harnesses separately.

Are the torque values in foot-pounds or Newton-meters?

Imperial units – foot-pounds – are used throughout. The specification tables also list the Newton-meter conversion if you need it, but all the procedures reference foot-pounds.

How do I find the hydraulic pump pressure adjustment?

Go to section 12 (Hydraulic Pump) and the maintenance standard in LP04. That chapter gives the pressure setting and the test port location. Do not adjust without following the procedure – you can overspeed the engine or blow a seal.

Listen, I have torqued enough head bolts to know that cheap manuals cost you in the long run. This is the only document I trust for the FIAT Kobelco SK series. Access the Factory Manual – put it on your tablet or print the pages you need for the job. Keep it clean, keep it dry, and use it every time. Your machine will thank you, and your wallet will too.