Kobelco SK25SR-2 Workshop Shop Manual (2000-2003) – 175 Pages | Excavator | Factory Grade PDF

Kobelco SK25SR-2 Hydraulic Excavator Shop Manual - 2003 Edition

This professional workshop documentation provides exhaustive maintenance and repair protocols for the Kobelco SK25SR-2 series, ensuring maximum machine uptime through factory-verified procedures. The manual integrates a critical unique maintenance insight regarding the hydraulic boost circuit: a specialized check valve positioned between the control valve and hydraulic tank specifically maintains a boost circuit to prevent negative pressure and cavitation in the slewing motor during inertia-driven stops. Precise adherence to the air-releasing procedures for travel and slewing motors is vital to prevent immediate equipment damage upon restarting the system after fluid changes.

Technical Applicability & Serial Ranges

The specifications and performance data in this manual are restricted to the following machine designations and serial number prefixes:

• Standard Series SK25SR-2 (EU & OCEANIA): PV08-20001 and higher
• Standard Series SK25SR-2 (USA): PV08-20001 through PV08-20762
• Updated Series SK25SR-2 (USA/North America): PV08-20763 and higher
• Technical Revision SK25SR-2 (KAI): PV09-22001 and higher

Operational Efficiency & ROI Proof Points

• Precision Calibration: High and low idling speeds are factory-set at 2550±50 rpm and 1300+80 rpm respectively to optimize fuel consumption rates, which average 2.65–3.09 L/h under standard load factors.
• System Integrity: Main relief pressures are benchmarked at 230 kgf/cm² (3270 psi) for P1 and P2 circuits, ensuring the hydraulic system operates at peak force without compromising seal longevity.
• Maintenance Standardization: Includes a detailed Standard Maintenance Time Table, allowing service managers to accurately estimate labor costs and schedule downtime for everything from bucket pin replacement (0.1 hours) to slewing motor overhaul (3.0 hours).

Document Metadata

• Book Code: S5PV0001E2
• Edition: Second Revision (January 2003)
• Total Pages: 175
• Language: US English

Technical Depth & Factory Benchmarks

System diagnostics rely on specific factory benchmarks to differentiate between normal wear and recoverable performance deterioration. The manual provides service limits for critical components:

• Engine Compression: Standard pressure is 3.4±0.1 MPa (35±1 kgf/cm²) at 250 rpm.
• Lubrication Pressure: Benchmarked at 294±49 kPa (3.0±0.5 kgf/cm²) at 2000 rpm.
• Hydraulic Relief Settings: Main Relief (P1, P2) at 230 kgf/cm²; Main Relief (P3) at 180 kgf/cm²; Overload Relief at 280 kgf/cm².

Visual Navigation Aids

The manual utilizes standardized color-coding and schematics to simplify complex troubleshooting:

• Hydraulic Circuit Diagrams: Detailed maps for Neutral, Travel, Slew, and Combined circuits (e.g., Travel/Boom raise).
• Color-Coding Standards: Orange denotes main pump drive pressure (50-280 kgf/cm²), while Red identifies primary pilot pressure (35-40 kgf/cm²).
• Component Location Keys: Annotated 3D views of the upper structure and undercarriage facilitate rapid part identification during disassembly.

Table of Contents

1. Specifications: Machine dimensions, performance curves, and component weights.
2. Maintenance: Safety precautions, tools, and unit conversion systems.
3. System: Hydraulic circuit operation, electrical system summaries, and component architecture.
4. Disassembling: Step-by-step removal and installation for upper structure and travel systems.
5. Troubleshooting: Logic-based diagnostic flows for hydraulic and engine malfunctions.
6. Engine: Technical data and performance curve for the Yanmar 3TNE74-NYBB.
7. Optional Attachments: Installation procedures for secondary hydraulic tools.

Operational Limits & Specifications

Maximum durability is maintained by adhering to exact torque sequences and fluid requirements:

• Lubricant Specifications: Engine oil volume is 3.5L (Max) / 2.0L (Effective); Cooling water capacity is 2.7L.
• Fastener Torque: M12 (7T Classification) bolts require 8.1±0.8 kgf-m (59±5.8 lbf-ft) for standard dry applications.
• Hydraulic Fitting Torque: 1/2" PF nominal screw size joints require 11±1.0 kgf-m (79.6±7.2 lbf-ft) with O-ring sealing.

FAQ

Does this manual cover the newer production units of the Kobelco SK25SR-2 for the North American market? Yes, the documentation specifically applies to the SK25SR-2 model, covering serial number ranges starting from PV08-20001 for standard units, and includes specific updates for the PV08-20763 and higher series used in North American (USA) distribution.

What are the primary hydraulic relief pressure settings required for system calibration? According to the technical specifications, the main relief valves for the P1 and P2 pump circuits must be set to 230 kgf/cm² (3270 psi), while the P3 pump circuit operates at a relief pressure of 180 kgf/cm² (2560 psi).

Can I find detailed engine performance data for the installed power unit? The manual contains a dedicated "ENGINE" section (Section 6) providing full technical data for the Yanmar 3TNE74-NYBB engine, including a standard high idling speed of 2550±50 rpm and a low idling benchmark of 1300+80 rpm.

Does this document provide specific diagnostic procedures for the slewing system? The manual details the operation of a specialized boost circuit and check valve system designed to prevent cavitation in the slewing motor; it includes diagnostic flowcharts in the Troubleshooting section to address issues such as hunting or lack of power in the slewing motion.

How does the digital format of this service manual assist with urgent field repairs? The digital version allows for immediate navigation to critical "Visual Navigation Aids," such as the color-coded hydraulic circuit diagrams and the electrical system summaries, which can be printed individually for use as a reference directly at the machine during complex diagnostic tasks.