08-21-2025, 12:57 PM
Overview of Kobelco SK135
The Kobelco SK135 is a versatile medium-sized hydraulic excavator widely used in construction and earthmoving since its introduction. It is recognized for its compact design, small rear swing radius for tight sites, and efficient fuel consumption. The excavator is powered by a 74 kW (100 hp) diesel engine with advanced electronic controls to optimize performance and reduce emissions, coupled with a state-of-the-art hydraulic system for smooth, powerful digging and lifting operations.
Typical Starting Problems and Symptoms
Common starting problems reported with the SK135 include:
An operator of a 2015 SK135SR reported multiple start failures during winter months, traced to a failing glow plug module and intermittent crankshaft sensor. Replacement of the module and sensor resolved the problem entirely, with machine reliability improving significantly during cold starts.
Glossary
Starting issues in Kobelco SK135 excavators typically stem from electrical, fuel supply, or sensor malfunctions. A structured diagnostic approach focusing on battery health, fuel system integrity, glow plug functionality, and sensor data helps resolve most start problems. Preventive maintenance aligned with OEM recommendations greatly reduces downtime and enhances operational reliability across varied working environments.
The Kobelco SK135 is a versatile medium-sized hydraulic excavator widely used in construction and earthmoving since its introduction. It is recognized for its compact design, small rear swing radius for tight sites, and efficient fuel consumption. The excavator is powered by a 74 kW (100 hp) diesel engine with advanced electronic controls to optimize performance and reduce emissions, coupled with a state-of-the-art hydraulic system for smooth, powerful digging and lifting operations.
Typical Starting Problems and Symptoms
Common starting problems reported with the SK135 include:
- Engine cranks but fails to fire or starts intermittently
- Engine turns over slowly or with reduced speed
- Sudden loss of power after startup or stalling shortly after starting
- Difficulty maintaining engine idle
- Error codes related to electronic engine or fuel system controls observed on monitor panel
- Battery and Electrical Issues: Low battery voltage, poor connections, or failing starter motor can cause weak cranking insufficient to achieve start.
- Fuel Supply Problems: Air in fuel lines, clogged fuel filters, or failing fuel pump reduce fuel delivery. Contaminated fuel can clog injectors or filters.
- Glow Plug or Preheating System Failure: In cooler environments, defective glow plugs or temperature sensors can prevent ignition.
- Sensor and ECU Malfunctions: Faulty engine speed sensors, fuel pressure sensors, or engine control unit (ECU) glitches may inhibit proper fuel injection timing.
- Hydraulic System Related Issues: Some sensors and control logic integrate hydraulic system status during startup; faults here can cause delays or failures.
- Injector Problems: Worn or leaking injectors lead to inefficient combustion and starting difficulties.
- Air Intake and Exhaust Blockages: Dirty air filters or restricted exhaust can affect combustion air supply.
- Verify battery voltage and inspect all electrical connectors, ensuring clean and tight connections.
- Bleed fuel system to remove air, replace fuel filters with recommended parts, and inspect fuel pump function.
- Test glow plugs and preheat circuits; replace faulty glow plugs promptly.
- Use diagnostic tools to scan for error codes and live sensor readings, focusing on fuel rail pressure, crankshaft position sensor, and engine coolant temperature.
- Inspect hydraulic fluid levels and system pressure to rule out sensor or safety interlock issues.
- Check air filter condition, clean or replace as necessary.
- Conduct injector flow and leakage test to identify faulty injectors.
- Regularly replace consumables such as fuel and air filters based on operating hours.
- Maintain a routine battery health check, especially in colder climates where cranking power is critical.
- Use high-quality diesel with additives recommended for electronic common rail engines.
- Keep ECU software updated to benefit from the latest diagnostic features and performance improvements.
- Schedule annual glow plug checks and replace all at once if any show weakness.
An operator of a 2015 SK135SR reported multiple start failures during winter months, traced to a failing glow plug module and intermittent crankshaft sensor. Replacement of the module and sensor resolved the problem entirely, with machine reliability improving significantly during cold starts.
Glossary
- Glow Plug: Heating element used in diesel engines to warm combustion chambers for easier cold starts.
- ECU (Engine Control Unit): Electronic device controlling fuel injection timing and quantity to optimize combustion.
- Crankshaft Position Sensor: Sensor that monitors the rotational speed and position of engine crankshaft.
- Fuel Bleeding: Process of removing trapped air from fuel lines to restore consistent fuel flow.
- Injector Leak Test: Procedure to identify leaks or flow issues in fuel injectors.
Starting issues in Kobelco SK135 excavators typically stem from electrical, fuel supply, or sensor malfunctions. A structured diagnostic approach focusing on battery health, fuel system integrity, glow plug functionality, and sensor data helps resolve most start problems. Preventive maintenance aligned with OEM recommendations greatly reduces downtime and enhances operational reliability across varied working environments.
