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Excavator Maintenance Guide For Heavy Duty Mechanic Apprentices
Written by Luis Montes Updated On January 13, 2026
The following guide compiles recommendations from some of the most popular heavy equipment manufacturers and our expert heavy-duty mechanics.
We’ll cover the following:
- Safety precautions during maintenance tasks.
- Tasks according to hour intervals.
- Maintenance tasks during winter, unique environmental conditions, and long-term storage.
If, besides mini excavators, you want to extend the useful life of your skid steer or compact track loader, check our “Ultimate Guide to Maintenance Hour Intervals.”
Maintenance Safety Precautions
Before reviewing the maintenance charts, let’s discuss some safety precautions we recommend for both before and during tasks. Although obvious to some of us, a rookie might ignore some of these recommendations, so if you need a break from your apprentice, ask him to read this article, especially this section.
How to Safely Park the Machine
Park the machine on a solid and level surface. Lower the bucket and blade (if equipped) to the ground. Pull the lock lever to the lock position. Run the engine at a slow idle speed (without load) for 5 minutes, then turn the key switch off.
Our article “Heavy Equipment Parking Mistakes” delves deeper into what not to do when parking an excavator.
Proper Way to Lift the Machine Off the Ground
When raising the machine above the ground with the bucket, keep an angle between the boom and the arm of 90 to 110°. The 90°-110° angle range maximizes the cylinder's hydraulic pushing power, properly balances the machine’s weight, and reduces the stress on structural components.
While the machine is off the ground, keep the safety lever (pilot control shut-off lever) up in the locked position, especially if you must work near it. Accidentally bumping into a control lever can cause the machine to drop, severely hurting or even killing you.
Image source: www.garagejournal.com.
Alternatively, when working on a piece of heavy equipment while it’s off the ground, avoid using bottle jacks to chock/block the machine. Instead, use wood blocks. Wood blocks are designed to safely block the machine.
Before and During Work
Whenever you need to inspect or perform maintenance on the engine or radiator, let it cool down sufficiently beforehand. Coolant burns are no joke. You can get 2nd degree burns that will take weeks to heal.
Even if you manage to turn the cap with a rag, you won’t have time to react as the coolant will quickly burst out. If you think you’ll be fast enough, so did this teenager, who severely burned his arm when he opened his car radiator cap while the engine was still hot.
When you’re ready to remove the radiator cap, first turn it slowly to release the pressure.
Do the same with the hydraulic oil cap, as the system is usually under built-up pressure due to system overload, clogged filters, or thermal expansion, as explained by Keith in our article “500 Hour Service Interval Guide for a John Deere 17G Excavator – Part 1.”
When searching for leaks, use a piece of cardboard or wood instead of your hands. The reason is that fluid leaks under pressure may not be visible and can penetrate the skin, causing high-pressure injection injuries. If you’ve never heard about the term, here’s an interesting (and very graphic) case study of a high-pressure injection hand injury.
Of course, never put any part of your body directly in front of any grease drain plug or valve.
The above brings up the importance of wearing proper PPE. We have a blog post that covers the essential features you should look for in personal protective equipment for heavy-duty tasks. Check it out.
If you must work on heavy equipment without PPE, avoid wearing loose-fitting clothing or jewelry, as rotating equipment could catch them. Contact with moving parts can cause severe injury or death due to amputation or entanglement (pinch point injuries), so besides loose clothing and jewelry, be aware of your hands and feet.
For indoor jobs with heavy equipment, ensure adequate ventilation. Either use an exhaust pipe extension or open doors and windows to bring in enough air.
Lastly, when working on the electrical system, disconnect it from the voltage source before starting.
Don’t strike high-pressure hoses or bend them beyond their recommended minimum bending radius, as this restricts fluid flow, increases system pressure drop, generates heat, and strains the pump. In severe cases, it can trigger erratic machine movement or slow actuator response.
Image source: www.kingdaflex.com.
Finally, thoroughly inspect hoses before installation. Don´t use bent or damaged hoses. Not only will they cause fluid loss, but they could also lead to uncontrolled movement of some parts—a strike or crush hazard.
Welding, Grinding, and Torching
Disconnect the battery ground cable (−) on the machine before welding to avoid damaging the ECM (Electronic Computer Module). Ideally, only qualified personnel should perform welding.
Welding, soldering, or torching over paint produces hazardous fumes. Some good practices for these types of tasks include:
- Perform welding in a well-ventilated and prepared area. Store flammable objects in a safe place before starting welding.
- If possible, remove paint before welding or heating. Wear a respirator when sanding or grinding paint.
- Clean any solvents with soapy water before welding.
- Dispose of paint and solvent properly.
- Avoid potentially toxic fumes and dust.
- Allow fumes to disperse for at least 15 minutes after welding or heating.
Don’t weld, solder, or torch near pressurized fluid lines or other flammable materials:
- You can accidentally cut pressurized lines.
- Install temporary fire-resistant guards to protect hoses and other materials before commencing work.
- If you need to weld or flame-cut pipes containing flammable fluids, drain them and thoroughly remove the fluids with a nonflammable solvent.
Battery Check, Charge, and Handle
Don’t check a battery's charge by placing a metal object across its posts. Use a multimeter or a proper battery tester.
Don’t charge a frozen battery; it may explode. Before charging the battery, check for physical damage and let it thaw in a warm room for a day or two.
Another cause of battery explosion is using or charging the battery when the electrolyte level is below the specified level.
Image source: www.youtube.com/@BudgetMechanicHawaii.
Ensure that metal objects (such as tools, rings, and watch straps) do not come into contact with both battery pole studs. If possible, install protections over the battery pole studs.
Don’t tilt a battery in any direction. The battery electrolyte may leak out.
Cleaning the Machine
Don’t use water or steam to clean sensors, cable connectors, or the inside of the cabin.
When cleaning parts, use a non-combustible cleaning solvent. Never use a flammable fluid such as diesel fuel or gasoline.
About Fluids
Generally, it is best to avoid mixing different brands or types of oil. Oil manufacturers blend additives to meet certain specifications and performance requirements. Mixing different oils can interfere with the proper functioning of these additives and degrade lubricant performance.
To avoid engine damage, reduce oil and filter service intervals by 50% when using BioDiesel blends greater than B20. Oil analysis may allow longer service intervals.
Don’t mix zinc-based and zinc-free hydraulic oils. Flush the system when changing from zinc-free to zinc-based oils. Neither mix petrol and diesel fuel.
When mixing coolant concentrate with water, use a concentration of at least 40% or no more than 60% coolant. Less than 40% makes the additives inadequate for corrosion protection. A concentration above 60% can cause the coolant to gel, leading to cooling system problems.
Mix base engine coolant concentrates (ethylene glycol and propylene glycol) with distilled, deionized, or demineralized water.
Don’t mix ethylene glycol- and propylene glycol-based coolants. A mix can make it difficult to predict the efficiency of freeze protection. If mixing for top-off is unavoidable, it is recommended to flush the cooling system at the next convenient opportunity.
Use tap water as a coolant only in emergencies and as a short-term fix. Tap water as a coolant can cause foaming, corrosion of iron and aluminum surfaces, scaling, and cavitation, even when coolant conditioners are added. Drain the cooling system and refill it with the recommended engine coolant as soon as possible.
Mini Excavator Hour Intervals Maintenance Schedule
From checking fluid levels to replacing filters, this list covers all the essential maintenance tasks for your mini excavator, based on the hour meter.
Services Schedule
- Clean the machine.
- Do a visual inspection for damages or wear on the machine, rims, and attachments.
- Check and adjust the air conditioner belt—if equipped.
- Adjust track tension (sag).
- Inspect/Replace sprockets.
- Check/Replace tracks.
- Check any unauthorized welding that might lead to a loss of warranty.
- Drain/Clean water and sediment from the fuel tank.
- Check/Change bucket teeth or cutting edges.
- Check and tighten all bolts and nuts, particularly the undercarriage and attachments.
- Check/Clean/Replace the cab fresh air filter—if equipped.
- Check/Clean/Replace the cab recirculation air filter—if equipped.
- Clean/Replace engine air filter primary and secondary elements.
- Lubricate the front windscreen rail.
- Check electrical connections and wiring.
- Adjust the blade frame.
- Inspect/Replace window wiper.
- Check the windshield washer fluid level.
- Check and drain the water separator fuel filter.
- Check the coolant level.
- Check the engine oil level.
- Check the hydraulic oil level.
- Check the fuel level.
- Check for the correct operation of all indicators and lights.
- Check the battery connections, cables, and electrolyte levels.
- Check the condition of ROPS mounting hardware.
- Check and clean the engine air cleaner dust unloader valve.
- Check/Lubricate pivot points.
- Check the seat belt condition.
- Check/Change the fuel filter.
- Check/Adjust the fan belt tension.
- Check/Replace the control console lockout.
- Lubricate the swing bearing and gear.
- Lubricate the bucket cylinder and link pins.
- Lubricate boom cylinders and pins.
- Lubricate arm cylinders and pins.
- Lubricate link coupling.
- Change engine oil and filter.
- Lubricate the swing bearing and gear.
- Lubricate the bucket cylinder and link pins.
- Lubricate boom cylinders and pins.
- Lubricate arm cylinders and pins.
- Lubricate link coupling.
- Clean the spark chamber.
- Check/Adjust/Replace belts.
- Check the final drive oil.
- Change the hydraulic filter element.
- Check travel gearbox oil level.
- Drain water and sediment from the hydraulic tank.
- Check/Replace the radiator hoses and clamps.
- Change the engine oil and filter.
- Check/Change the fuel filter.
- Check/Replace the exhaust manifold for damages and leakages.
- Replace the air intake line.
- Check/Clean the radiator fins.
- Check/Change fuel pipes, hoses, and clamps.
- Check/Replace the hydraulic pump, suction, and pressure hose.
- Check/Replace hoses for boom, arm, and bucket cylinder.
- Check/Replace the quick coupler lock mechanism.
- Lubricate the control lever universal joint.
- Take Sample of the following fluids:
- i. Engine oil.
ii. Hydraulic oil.
iii. Transmission oil.
iv. Travel gear case oil.
v. Coolant.
vi. Fuel.
- Change the final drive/travel gearbox oil.
- Change swing machinery oil.
- Check/Adjust engine valve clearance.
- Change engine coolant.
- Change hydraulic oil and filter.
- Check the crankcase breather system.
- Check/Clean/Replace fuel injectors, nozzles, and pump.
- Check the fuel injection timing.
- Check the alternator and starting motor.
- Clean the machine.
- Do a visual inspection for damages or wear on the machine, rims, and attachments.
- Check and adjust the air conditioner belt—if equipped.
- Adjust track tension (sag).
- Inspect/Replace sprockets.
- Check/Replace tracks.
- Check/Replace tracks.
Minimizing the Effects of Cold Weather
Replace the engine and hydraulic oil with winter-grade fluids.
Only use winter-grade fuel (No. 1-D in North America). Winter-grade fuel has a lower cloud point and a lower pour point. The cloud point is the temperature at which wax begins to form in the fuel. Wax causes fuel filters to plug. The pour point is the lowest temperature at which a fuel can flow.
On average, winter-grade diesel fuel has a lower Btu (heat content) rating. Thus, it may reduce power and efficiency, but shouldn’t affect other engine performance. Check your fuel grade before troubleshooting for signs of low power in cold-weather operations.
When operating with BioDiesel blends, the wax formation can occur at warmer temperatures. Use B5 or lower blends below 0°C (32°F). Use only winter-grade petroleum diesel fuel when the temperature is below -10°C (14°F).
Fill the fuel tank at the end of each day's operation to prevent water condensation and freezing during cold weather.
Fill the washer system with an antifreeze window cleaner.
If using winterfronts, never totally close off the grill frontal area. Leave approximately 25% of the grill's center area open. Don’t install the waterfront directly to the radiator core.
If equipped with a thermostatically controlled radiator shutter system, regulate it to open the shutters when the coolant reaches 93 °C (200 °F) to prevent excessive intake manifold temperatures.
Clean the excavator after work. Pay special attention to the crawlers, the attachments, and the piston rods of the hydraulic cylinders. If you clean the excavator with a water jet, park it in a dry, frost-free, and well-ventilated enclosed space.
If necessary, park the excavator on boards or mats to prevent freezing to the ground.
Remove the battery after work and store it in a warm, dry place.
Apply talcum powder or silicone oil to all rubber seals, including those at the windows, the cabin door, and the side window guide rails.
Lubricate all locks (except the starter switch) with graphite lubricant, and grease the cab door hinges.
Maintenance According to Specific Environmental Conditions
Besides winter-related maintenance tasks, other special conditions will also affect your mini excavator, requiring you to shorten service intervals to as frequently as daily.
Near the Ocean
Before operating, check the tightness of the plugs, all hoses, and drain valves.
After working, clean the machine with fresh water and replenish the grease to the attachment pins or the areas in contact with seawater.
Service electrical equipment often. Use dielectric grease at all harness connection points to improve sealing and prevent corrosion.
Dusty Environment
Check, clean, or replace the air cleaner elements at shorter service intervals, as well as the fuel system filter and strainer.
Clean the oil cooler screen regularly to prevent clogging of the radiator core.
Clean the electrical equipment regularly, particularly the starter and the alternator’s commutator surface.
High Ground Altitudes
Change the engine oil and filter at half regular service intervals.
Altitudes above 6,600 ft affect the ignition system. Check it regularly.
Low-Quality Fuel
We recommend shortening the service intervals of the following maintenance tasks:
- Drain the sediments in the fuel tank.
- Change the engine oil and filter.
Long-Term Storage
Change the engine oil and filter.
Check the hydraulic oil level.
Add hydraulic oil if necessary.
Fill the fuel tank to prevent condensation. Don’t use BioDiesel during machine storage. When using BioDiesel blends, switch to petroleum diesel for long-term storage.
Add an antirust agent to the coolant. In cold weather, add antifreeze or drain the coolant completely. Attach a “No Water in Radiator” tag to a visible location if there is no coolant in the system.
Lubricate all grease points and paint the necessary areas to prevent rust.
Replace air cleaner elements.
Thoroughly wash the machine to remove dirt, soil, and debris.
Store the machine in a dry, protected place. If stored outside, cover it with a waterproof cover.
If possible, retract all hydraulic cylinders. If not, coat exposed cylinder rods with grease.
Remove the battery and store it in a dry, protected location after it has been fully charged. Otherwise, disconnect the negative battery cable from the (–) terminal. Charge the battery regularly.
Oil films on sliding surfaces may break down over time. Operate the travel, swing, and digging functions for 2 to 3 cycles each to lubricate the sliding surfaces at least once a month.