Essential Skills for Excavator Maintenance and Repair

A qualified construction machinery operator should not only master the driving skills but also understand some basic maintenance and repair of the machinery. However, not every mentor teaches these aspects. Some novice excavator drivers may barely manage tasks but lack knowledge about the gearbox and turntable needing gear oil, let alone knowing when to replace them. They might confuse engine oil filters with diesel filters or struggle with air bleeding or identifying the number of hydraulic oil filters. Facing minor faults, they might feel at a loss.

One common issue excavator drivers encounter is the inability to start the machine. If it's a persistent problem, especially in winter, it could indicate engine-related issues like valve leakage or excessive piston ring gap leading to inadequate compression temperature. However, temporary startup issues, such as the engine failing to start suddenly after previously running fine, can usually be traced back to two main reasons: electrical failure or fuel supply issues.

In cases of electrical failure, if the starting motor remains silent, it suggests a lack of power. Checking the battery terminal for poor contact or damage is advisable. Some models require the hydraulic main switch to be on for starting, which might initially confuse novices. If the starting motor turns slowly and sounds weak, it indicates a low battery, prompting a check of the alternator belt and possibly a test of the charging system. If all seems normal, informing the excavator owner about the battery issue is the next step.

If the starting motor spins normally but the engine fails to start, it suggests fuel supply issues. Cleaning the diesel pipeline for blockages, especially the small filters at the bottom of the diesel tank and hand pump, is essential. Air may also get trapped during filter replacement; loosening the air vent screw and priming with the hand pump can purge the air. It's worth noting that some smaller excavators use an electronic pump instead of a hand pump, which, if faulty, can also prevent engine startup or cause immediate shutdown after starting.

Occasionally, drivers may face the opposite problem: the inability to shut down the machine even after removing the key, usually due to a malfunctioning shutdown cable. Manually adjusting the cable's position under the engine hood can resolve this issue. Similar issues with the shutdown cable can also cause startup failures.

If starting the engine is easy when cold but difficult when warm, it could indicate poor diesel quality causing pump wear, necessitating pump calibration. This requires specialized expertise, with numerous service providers, especially in Henan province, offering pump calibration services.

Encountering a situation where the excavator fails to respond despite starting the engine could signal a catastrophic issue, such as a broken connection between the engine and hydraulic pump. Although rare, it's a terrifying scenario where the machine continues to operate even when the controls are in the neutral position.

Various symptoms, like engine overheating, loss of power, and bubbling in the secondary water tank, may indicate blown cylinder head gaskets. While seemingly minor, if left unaddressed, these issues can lead to major problems. Hence, it's crucial to observe and diagnose various symptoms promptly while working.

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