Relief valve settings, track tension and swing reduction service for the Kobelco SK150LC III hydraulic excavator are settled in one 770-page shop manual, Kobelco publication S5YM0001E-00. As a Kobelco SK150LC III shop manual PDF, it pairs a hydraulic system diagram tracing the neutral, travel, swing and bucket circuits with wiring diagrams for the electrical system. Troubleshooting runs system by system. Drive, hydraulic, swing, travel, attachment, control and electrical faults each get their own section, and the travel chapter works through track links, upper and lower rollers, the idler and the track tension assembly. Set travel main relief to 350-385 kg/cm² (4980-5050 psi), then confirm primary pilot pressure at 47-53 kg/cm² (670-754 psi). When your fault sits in the travel circuit, the hydraulic diagram shows how that circuit is routed. Bookmarked by system and searchable as text, the PDF lets you finish that relief check to Kobelco's own figures.
What's Inside This Kobelco SK150LC III Manual
| System | Pages | Key Topics |
|---|---|---|
| Operation and Controls | 2-7 | |
| Preventive Maintenance | 8-9 | |
| Specification | 10-25 | Location of Components, General Dimensions, Specifications and Performance |
| Location and Weight of Components | 26-31 | Weight of Components, Transportation Weight |
| Maintenance Standards and Test Procedures | 32-77 | Performance Inspection Standard |
| Troubleshooting | 78-103 | Drive System, Hydraulic System, Swing System, Travel System, Attachment System, Control System, Electrical System |
| Tightening Torques for Fasteners | 104-107 | Capscrews, Nuts, Sleeves, Special Spanner, Screw Locking Compounds |
| Troubleshooting and Maintenance Standards | 108-109 | Application Table, Maintenance Standards, General Repair Instructions |
| Systems Overview | 110-111 | |
| Drive System | 112-125 | Power Plant, Hydraulic Pump, Coupling, Radiator, Suction Stopper |
| Hydraulic System | 126-147 | Hydraulic System Diagram, Neutral Circuit, Travel Circuit, Swing Circuit, Bucket Circuit |
| Swing System | 148-168 | Slewing Ring, Swing Control Valve, Swing Motor Assembly, Swing Reduction Unit |
| Travel System | 169-219 | Lower Machinery, Track Link, Upper Roller, Lower Roller, Idler, Track Tension Assembly |
| Attachments | 220-237 | Attachment System, Removal and Installation of Attachment |
| Engine Control Installation | 238-249 | Travel and Operate Control System, Work Control System |
| Upper Frame | 250-261 | Hydraulic Oil Tank, Fuel Tank, Removal and Installation of Cab |
| Electrical System | 262-269 | Location of Electrical Components, Wiring Harnesses |
| Fresh Air Heater | 270-275 | Construction of Main Components, Operating Principle |
| Engine | 276-486 | Lubricating System, Fuel System, Turbocharger |
| Shop Manual Components | 487-585 | Hydraulic Pump, Regulator, Pilot Valve |
| Control Valve | 586-770 | Holding Valve, Hydraulic Cylinder |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Primary pilot pressure | 47-53 kg/cm² (670-754 psi) | p. 35 |
| Travel main relief pressure | 350-385 kg/cm² (4980-5050 psi) | p. 35 |
| Upper Limit Pressure (Variable loading mode switch) | 16.0 ± 1.0 kg/cm² (227 ± 14 psi) | p. 54 |
| Lower Limit Pressure (Variable loading mode switch) | 11.0 ± 1.0 kg/cm² (156 ± 14 psi) | p. 54 |
| Tightening torque for shoe bolt | 95 ± 2 kgf·m (687 ± 14.5 ft-lbs) | p. 213 |
| Tightening torque for filter assy (2-1) | 7-8 kgf·m (51-58 ft-lbs) | p. 645 |
| Tightening torque for check valve assy (3-7) | 4.8-5.5 kgf·m (35-40 ft-lbs) | p. 645 |
| Torque for capscrews on slewing ring | First 15 kgf-m (108 ft-lbs), Second 57.5 ± 5.5 kgf-m (415 ± 40 ft-lbs) | p. 168 |
| For reduction unit mounting capscrews | 28.5 ± 3 kgf·m (206 ± 22 ft-lbs) | p. 211 |
| For sprocket mounting capscrews | 28.5 ± 3 kgf·m (206 ± 22 ft-lbs) | p. 211 |
| Swing speed | 11.4 rpm | p. 15 |
| Engine rated output | 100 ps / 2,300 rpm | p. 15 |
Kobelco SK150LC III Common Problems This Manual Covers
Kobelco SK150LC III hydraulic pump connection at engine flywheel making unusual noise during operation
Remove the dust plug under the engine flywheel and check for rubber pieces or particles. Particles mean the coupling element is broken: disassemble and repair. If clean, inspect for a worn coupling hub spline or loose hub setscrew. Replace the hub or retighten setscrew (27-5) to 10~12 kgf-m following page 118.
Manual Section: Drive System Troubleshooting p. 80Engine starts and runs normally but the machine does not operate on any control
Check hydraulic tank level and replenish specified oil to standard. Abnormal pump noise means a damaged pump: disassemble and repair. Otherwise measure primary pilot pressure against 47-53 kg/cm² (page 35), watching for hot oil per page 52. If low while the gear pump delivers oil, repair or replace the pilot relief valve. Relieve all pressure before opening pilot piping (page 4), then clean or repair clogged or leaking lines.
Manual Section: Drive System Troubleshooting p. 80Hydraulic oil temperature rises abnormally high during normal digging and travel work cycles
Check oil volume and replenish specified oil to the standard level. Inspect the oil cooler and circulation route for clogging, and adjust fan belt tension or replace the belt. Measure main, port and travel relief set pressures; attachment main relief should read 300-305 kg/cm² on page 35. Readjust only if below standard, never when within tolerance (page 56). Watch for hot oil per page 52. If main relief runs often, reduce load.
Manual Section: Hydraulic System Troubleshooting p. 81Upper structure swing speed drops low in both directions during normal swing operation
Measure swing speed against 11.4 rpm (page 15), then compare secondary pilot pressure on LH and RH sides. Clean or repair clogged or leaking pilot piping, relieving all pressure first (page 4). Check that the swing control valve spool moves smoothly by hand. Verify swing relief pressure against 265-295 kg/cm² on page 35, watching for hot oil (page 52), and adjust or replace the valve. Out-of-spec swing motor drain rate means a broken motor.
Manual Section: Swing System Troubleshooting p. 83Travel action is powerless during travel only operation, with weak drive from the travel motors
Check travel brake pressure against standard, then measure travel motor drain rate; out-of-spec drain means the travel motor is faulty. Remove the parking brake spring, draw out the piston and confirm it moves lightly by hand. Relieve all pressure before opening the brake release circuit (page 4), and disassemble and clean it if clogged with dirt. If symptoms remain unchanged, inspect the travel reduction unit.
Manual Section: Travel System Troubleshooting p. 88Abnormal noise heard from the swing area during swing motion of the upper structure
Check lubrication to the swing ring gear and pinion and supply grease to the grease bath. Grease the swing bearing for a light fault; disassemble and repair or replace if excessive. Unusual sound from the swing relief valve means air inside: repair or replace it. Confirm the swing motor piston is not seized and bearing intact, then check the reduction unit.
Manual Section: Swing System Troubleshooting p. 85Frequently Asked Questions
How do I access the diagnostic error-code screen on a Kobelco SK150LC III?
To access the diagnostic error-code screen, turn the starter key switch to the 'ON' position while pushing the buzzer stop switch. Then, depress the buzzer stop switch five times to display the engine rotation mark and controller part number. Pushing the buzzer stop switch on and off again will display the engine RPM on the 23rd out of 24 displays. p. 40
What is the procedure for troubleshooting weak or slow hydraulics on the SK150LC III?
If boom, arm, or bucket speed is low, first check if the speed is low only in composite operation. If not, check if LH/RH travel speeds are within standard levels. If they are, check if the secondary pilot pressure is within standard levels. If the pressure is standard, check if the engine revolution is within standard levels. If the engine revolution is normal, check the pilot pressure for the confluent flow spool. p. 91
What is the standard valve clearance for the Isuzu 4BD1 engine in the Kobelco SK150LC III?
The standard valve clearance for both intake and exhaust valves on the ISUZU 4BD1 engine is 0.40 mm (0.016 in) when the engine is in a cold state. p. 25
What is the tightening torque for the main relief valve on the SK150LC III?
The main relief valve (MR1 and MR2) on the SK150LC III should be tightened to a pressure of 335 kgf/cm² (4760 psi) as indicated in the performance inspection standard. p. 34
What is the procedure for bleeding air from the fuel system on the ISUZU 4BD1 engine?
To bleed air from the fuel system, loosen the feed pump cap on the injection pump and the fuel filter fuel return eye bolt. Operate the feed pump until no more bubbles are visible in the fuel being discharged from the fuel filter return eye bolt. Finally, retighten the eye bolt and operate the feed pump several times to check for leaks. p. 309
Is this Kobelco SK150LC III manual a download or a disc?
Delivery is instant: a 770-page searchable PDF is yours the second checkout clears. Laptop, tablet, or phone, all fine.
Is this Kobelco SK150LC III manual print-friendly?
Yes. Many mechanics print the section they need for their own shop and bring it to the bench.
