Excavators are highly integrated electromechanical hydraulic heavy machinery, and due to their operation in harsh and complex construction environments, their lifespan, performance, and reliability heavily depend on the quality of daily maintenance. For operators and managers, understanding the key points of maintaining the major components of an excavator is fundamental to extending equipment lifespan, reducing malfunctions, and improving efficiency. This article will introduce the daily maintenance methods and precautions for six major components: the engine, hydraulic system, undercarriage (chassis), working mechanism (boom, dipper arm, bucket, pins, etc.), electrical system, and attachments/connecting parts (pins, couplings, quick-change mechanisms, etc.), focusing on their functionality and operability.
Maintenance Focus and Objectives
The engine is the power source of the excavator, responsible for fuel combustion, mechanical drive, and power generation. Proper engine maintenance ensures stable power output, reduces fuel consumption, and prevents major malfunctions. Key Points for Daily Maintenance
1.1 Engine Oil and Oil Filter
Check the engine oil level and quality before and after each shift. If the oil is dark in color or contains excessive impurities, replace it immediately.
Oil and oil filter replacement must be performed according to the manufacturer's recommended intervals; do not extend the interval (for older models, the interval can be shortened appropriately).
Use genuine or equivalent quality oil filters; do not use low-quality filters to save money.
1.2 Diesel System and Water Separator
Drain water from the lowest point of the fuel tank and the water separator every morning to remove water and impurities.
Use only reputable fuel suppliers for diesel. Filter the fuel through gauze or a mesh filter before adding it to the tank.
Replace the diesel filter regularly and check for any metal shavings or copper particles.
1.3 Air Filter
If the outer filter is heavily soiled, clean it with compressed air (from inside to outside). Ensure the air pressure is not too high to avoid damaging the filter structure.
The inner filter should not be cleaned with compressed air; it should be replaced regularly.
Replace the inner filter at the same time as the outer filter after several cleanings.
1.4 Cooling System
Check the coolant level and concentration, ensuring no leaks, bubbles, or scale buildup.
Clean the radiator, water tank, oil cooler, etc. regularly (using low-pressure water or air).
Check the tension of the belts in the water pump and cooling system to ensure proper operation.
Prevent overheating or engine shutdown due to insufficient cooling under high-temperature conditions.
1.5 Engine Operation
Avoid prolonged idling at low speeds to prevent carbon buildup and oil line blockage.
Regularly check the valve clearance, turbocharger (if equipped), and exhaust system.
1.6 Start/Shutdown Procedures
Perform a complete check of the fuel, water, and lubrication systems before starting the engine.
Maintain idle speed for a few minutes after shutting down the engine to allow the components to cool gradually, preventing sudden temperature changes in the coolant.
Maintenance Focus and Objectives
The hydraulic system is the main power transmission path for the excavator's operations (lifting, extending, rotating, walking, etc.). Its reliability directly affects the excavator's efficiency and failure rate. Key Points for Daily Maintenance
2.1 Hydraulic Oil and Filters
Check the hydraulic oil level and quality before and after each shift, paying attention to color, temperature, and any abnormalities such as emulsification or black particles.
Replace hydraulic oil, return line filter, and pilot filter according to the manufacturer's recommended schedule. Reduce the replacement interval when using a hydraulic hammer or under high-impact conditions.
Ensure proper system purging after replacement to prevent air from entering and affecting stability.
2.2 Pipes, Fittings, and Seals
Check hydraulic hoses, steel pipes, and fittings daily for leaks, bulges, looseness, or cracks.
Replace worn or deformed O-rings and seals promptly.
When operating in wet or water environments, ensure waterproofing; avoid spraying high-pressure water directly onto solenoid valves or fittings.
2.3 Hydraulic Pump, Valves, and Actuators
Regularly check for blockages in the pump inlet screen and suction pipe.
Monitor pump, motor, and valve temperatures to prevent oil degradation due to overheating.
If operation is sluggish, jerky, or weak, promptly analyze for internal leaks, external leaks, or valve wear.
2.4 Swing and Travel Gearboxes & Gear Oil
Replace gear oil and filters in the swing and travel gearboxes periodically.
Check gear oil for water or metal particles.
2.5 System Function Check
Before operation, check each cylinder for oil leaks and piston rod for scratches or rust.
Check the status of valve blocks, distribution plates, pilot valves, and relief valves for sticking or abnormal response.
Conduct periodic hydraulic oil analysis (particle count, water content, etc.) to monitor system cleanliness.
2.6 Waterproofing and Dust Protection
The hydraulic system requires special attention to avoid water damage. If the operating depth exceeds design specifications, shut down and check system seals.
Prevent mud and sand from entering the system; during cleaning, ensure no debris enters the system through fittings.
Undercarriage components account for a significant portion of excavator repair costs; daily maintenance is crucial. Key Points for Daily Maintenance
3.1 Cleaning Mud and Debris
After each work shift, promptly clean the track, idler, sprocket, support roller, and support plate with water or tools to remove mud, stones, and other debris.
Pay special attention to any foreign objects trapped between the track and the support rollers.
3.2 Track Tension Adjustment
Select the appropriate tension based on terrain and working conditions: slightly looser tension for rocky ground, and slightly tighter tension for general soil conditions.
Excessive looseness can cause chain jumping, while excessive tightness accelerates wear on pins, idlers, and track links.
Regularly measure and adjust the tension (refer to the manufacturer's tension standard).
3.3 Idler, Sprocket, Support Roller, and Drive Wheel
Check daily that these rotating components turn smoothly, without binding, oil leaks, cracks, or bearing abnormalities.
Open the motor cover and check for mud buildup that may block the access path.
Lubricate the pins and bearings; apply grease regularly.
3.4 Pin and Bolt Tightening
Check daily for loose, missing, or broken pins, such as track pins, idler pins, and sprocket pins.
Tighten bolts, but not excessively, to avoid deformation.
Lubricate pins and bearings to reduce wear.
3.5 Chassis Structure Inspection
Inspect welds and brackets for cracks, deformation, and signs of fatigue.
Address any metal fatigue or cracks promptly with repairs or welding.
3.6 Rust Prevention
Apply rust-preventive grease to exposed metal surfaces during long-term storage.
Especially for pins, bushings, and other moving parts.
The working components directly bear the excavation load, and are subject to the most common wear and damage; they require meticulous maintenance. Key Points for Daily Maintenance
4.1 Structural Inspection
Check the boom, dipper arm, and bucket daily for cracks, bends, cracked welds, and signs of fatigue damage;
Replace or repair high-wear parts such as bucket teeth, tooth holders, side guards, and cutting edges promptly.
4.2 Pins, Bushings, and Bolts
Check for loose or missing pins and bolts daily; tighten or replace them as needed;
Lubricate pins, bushings, and sleeves regularly to maintain adequate lubrication;
Replace severely worn bushings promptly to prevent uneven wear on the structure.
4.3 Cylinders and Piston Rods
Inspect cylinders and piston rods for scratches, rust, and oil leaks;
Stop operation immediately and repair any leaks to prevent further damage;
Lubricate the seals around the cylinder and piston rod to maintain good sealing.
4.4 Connectors and Hinges
Grease all connecting hinges and sliding surfaces regularly;
Avoid dry friction or inadequate lubrication, which can cause severe wear.
4.5 Operating Procedures
Avoid sudden movements, over-digging, or overloading during operation;
Minimize operation under extreme conditions, such as high impact, hard rock, or uneven load distribution;
Lower the bucket and retract the boom when work is stopped to reduce external loads.
4.6 Regular Maintenance and Replacement
After extended operation, regularly replace or repair critical components (such as bucket teeth, bushings, and liners);
During major overhauls, carefully inspect for fatigue cracks, structural fatigue, and weld quality.
The electrical system is the core of modern excavator control, monitoring, and safety, encompassing instruments, sensors, electronic control units, wiring, and relays. Key Points for Daily Maintenance
5.1 Wiring and Connector Inspection
Check daily for loose, corroded, damaged, or worn insulation on wiring harnesses, connectors, and terminals;
Prevent water, mud, oil, or other contaminants from contacting the wiring to avoid short circuits or open circuits.
5.2 Battery and Starting System
Regularly check battery voltage, electrolyte level (or battery capacity for sealed batteries);
Keep battery terminals clean and securely tightened;
Disconnect the battery cables when the machine is stored for extended periods to prevent leakage;
Do not store objects (especially metal tools) in the battery compartment to prevent sparks or short circuits.
5.3 Controller, Relay, and Sensor
Check for moisture, corrosion, or damage on instruments, circuit boards, fuse boxes, and sensors;
Prevent rainwater from entering the control panel, electronic components, and bus interfaces;
Do not use wire or other materials to replace fuses, and do not use mismatched fuses.
5.4 Electrical Control Protection Measures
Avoid spraying high-pressure water on electrical components;
If the control box gets wet, dry, clean, and repair it as soon as possible;
Regularly check the reliability of the electrical grounding.
5.5 Operator Cabin Safety and Monitoring Equipment
Check that all alarms, safety interlocks, LCD/display screens, and electrical switches are functioning correctly;
Keep the operator cabin clean and tidy; do not place flammable or conductive materials in the cabin;
For machines equipped with monitoring or camera systems, regularly clean the camera and lens.
Although these components are not the main body, their quality and reliability often determine the excavator's ability to adapt flexibly and efficiently to different working environments. Key Points for Daily Maintenance
6.1 Quick-change Coupler and Connecting Devices
Check if the quick-change device is jammed, loose, or lacks proper lubrication;
Apply specialized lubricant (such as grease or oil) to key parts like connecting pins, pin holes, and locking pins;
For quick-change couplers with hydraulic locking mechanisms, check the locking status and seal condition for oil leaks.
6.2 Auxiliary Tools (e.g., Hydraulic Hammer, Rock Breaker)
Check that connecting hoses, fittings, and bolts are tight and free from leaks;
Lubricate the hammer head connection and check for any abnormalities in the impactor;
When not in use for extended periods, drain the oil and apply rust-preventive agent.
6.3 Hose Fittings and Hoses
Check daily for cracks, leaks, or bulges in hoses and fittings used for connecting attachments;
Regularly replace worn or aged hoses.
6.4 Control Valves and Interfaces
At the multi-function controller or electro-hydraulic control unit, check that electrical contacts and hydraulic interfaces are secure and free of dirt;
Keep any auxiliary valves (e.g., selector valves, relief valves, locking valves) clean and lubricated.
6.5 Protective Covers and Seals
Check the condition of seals and O-rings at attachment connections;
Replace any worn, cracked, or aged seals immediately.
The following is a suggested checklist for daily pre- and post-get off work inspections, for easy implementation by operators and supervisors:
|
Inspection items |
Main content |
Abnormal judgment/handling suggestions |
|
Lubricating oil level and quality |
Engine oil, hydraulic oil, coolant, fuel tank |
Blackening, bubbling, water mixing, low position, etc. should be dealt with immediately |
|
Cooling system |
Radiator, fan, water pipe, belt |
Clean, no leaks, fan rotates smoothly |
|
Chassis cleaning |
Clean the dirt on the tracks, rollers and guide wheels |
No debris blocking or jamming |
|
Track tension |
The tension is appropriate and the chain is not loose |
Adjust the tension and tighten the bolts |
|
Pins and bolts |
Looseness, falling off, and lubrication |
Add grease, tighten or replace parts |
|
Working device |
Cracks, wear, cylinder leakage |
Shutdown for maintenance and replacement of parts |
|
hydraulic system |
Filter status, oil temperature, leakage, action response |
Replace filter element, exhaust, repair oil leaks |
|
electrical system |
Battery voltage, wiring harness status, insurance, sensors |
Remove stitches for inspection, drying, cleaning and fuse replacement |
|
Accessory connection |
Quick changer status, hose connector |
Lubrication, oil leakage check, and connection tightening |
Operators should record any problems found during daily inspections, along with the solutions, to create a maintenance log for future trend analysis and troubleshooting.
8.1 Strictly Adhere to Manufacturer's Maintenance Manual
Prioritize the manufacturer's (or distributor's) "Operation and Maintenance Manual" for daily and periodic maintenance schedules, making adjustments based on actual operating conditions. 8.2 Adjustments Based on Environmental and Operating Conditions
In dusty, humid, or high-temperature environments, shorten the maintenance cycle and increase the frequency of cleaning and filter replacement.
8.3 Lubricant and Component Quality
Use only genuine, specification-compliant lubricants, filters, seals, bolts, and other components. Avoid using substandard parts. The quality of filtration and lubrication directly affects component lifespan.
8.4 Timely Response to Abnormal Alerts
If abnormal oil pressure, temperature, sluggish operation, unusual noises, or leaks are detected, diagnose and troubleshoot the problem immediately. Do not operate the machine with a fault.
8.5 Training and Responsibility Allocation
Operators and supervisors should receive comprehensive training and have clearly defined maintenance responsibilities. Daily, monthly, and annual maintenance tasks should be assigned to specific individuals, and maintenance records and fault handling should be reviewed and tracked.
8.6 Safety Precautions
During maintenance and inspection, ensure the machine is shut down, pressure is released, and the power is disconnected. Never operate the machine while under power or pressure.
As a high-value, complex piece of construction equipment, excavators, despite their robust structure and powerful drive system, rely heavily on meticulous daily maintenance and upkeep for reliable operation. By following the guidelines for the six key components, considering site conditions, establishing a sound maintenance program, and conducting thorough inspections, operators and supervisors can significantly extend machine lifespan, reduce downtime, and improve productivity.
We hope this "Daily Maintenance Manual for the Six Key Components of Excavators" provides valuable guidance for excavator operators and managers. If you would like more detailed information on inspection methods, troubleshooting procedures, or maintenance intervals for specific components (such as the engine, hydraulic system, or chassis), or if you need customized excavator solutions or related parts, please contact us.
