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5 Common Mini Excavator Problems and How to Solve Them

5 Common Mini Excavator Problems and How to Solve Them

5 Common Mini Excavator Problems and How to Solve Them

Reading time: 7 min

Mini excavators, also known as compact excavators, are among the most common and versatile machines on construction and excavation sites. Due to their small footprint and compact swing, they can fit into cramped spaces inaccessible by larger machines.

Not only are they compact, but they’re also precise. They’re the perfect machines for small and medium projects, such as residential landscaping projects or trenching between structures.

Like all heavy equipment, however, mini excavators need to be properly maintained in order to keep them operating safely and efficiently. Crucial to keeping a mini excavator in proper working condition is the implementation of a well-thought-out preventative maintenance program.

An effective preventative maintenance program will help your team identify potential maintenance needs associated with your mini excavator before they become problematic. Preventative maintenance is the key to keeping your mini excavator operational, avoiding costly downtime and preventing excessive service costs.

As you craft a preventative maintenance program for your mini excavator, you need to be aware of the maintenance problems commonly associated with this type of machine.

Common Mini Excavator Maintenance Issues

Over- or Under-greased Parts

Mini excavators are complicated machines with a host of moving parts. In order for these parts to function properly, it’s crucial that you keep your mini excavator well-lubricated.

Some components on your mini excavator which require regular greasing include:

  • Undercarriage (Pins and Bushings). Your mini excavator’s pins and bushings require daily greasing in order to avoid preventable maintenance issues. For best results, use between one and three shots of grease.
  • Slew Bearing. The slew bearing allows your machine’s cab to rotate on the chassis. Grease the slew bearing every 50 hours or as recommended in your machine’s service manual.
  • Track Rollers and Idlers. Track rollers and idlers are another important part of your excavator’s undercarriage. Depending on the make and model of your machine, they may need to be greased once per week or more frequently. Check your service manual for details.
  • Bucket Linkages. These are the components that connect your machine’s bucket to the boom arm. They should be greased daily.

Your mini excavator’s service manual should contain diagrams that illustrate the various greasing points on your machine. The manual should also specify how often each greasing point needs to be lubricated and how much grease should be used.

While greasing is an essential part of mini excavator maintenance, over- or under-greasing the components of your mini excavator may also cause problems.


Under-greasing your machine increases friction between its moving components, leading to excessive wear and tear and potentially causing breakdowns. When this occurs, repair costs can be significant.


Over-greasing on the other hand, can also cause problems. When too much grease is applied, it can damage seals or attract dirt and debris to the greasing point. This, in turn, may lead to unnecessary wear and tear on critical parts, eventually causing premature failure.

Improper Track Tension

Maintaining the health of your mini excavator’s tracks should be one of the key aims of your preventative maintenance program. 

The tracks on a mini excavator are what enable it to maneuver over rough and uneven terrain. Using the correct track tension keeps the machine efficient and safe to operate.

Using improper track tension can lead to a host of related maintenance problems. 

Tracks that are too tight can place excessive pressure and wear on the idlers, rollers and sprockets, leading to premature failure. Conversely, tracks that are too loose can cause the undercarriage to sag, leading to increased wear on the pins and bushings.

To avoid these problems, be sure to adjust the track tension according to the manufacturer’s specifications set out in the operating manual. The best way to prevent operating your machine on tracks that are too tight or too loose is by checking track tension at the start of each shift.

By visually inspecting the mini excavator’s undercarriage, you can quickly tell if you need to adjust your machine’s track tension. Tracks that are too loose will sag between the rollers, while tracks that are too tight will be visibly stretched, causing the machine to have difficulty moving.

Final Drive Motor Issues and Failure

The final drive motor is responsible for transferring power from your mini excavator’s hydraulic motor to its tracks. It plays a crucial role in the overall performance of the machine and increases torque, allowing you to carry out power-intensive tasks like excavation, trenching and digging.

Some common signs of a faulty final drive motor include strange noises like grinding or knocking, reduced power, resistance when turning or maneuvering the machine or leaking oil from the drive motor. If you notice any of these issues with your mini excavator, stop to investigate the problem before operating the machine further.

One common reason for final drive motor failure is a lack of proper maintenance. Over time, dirt, debris and other contaminants can accumulate around the final drive motor, causing it to overheat. Regular maintenance, including clearing debris from around the drive motor and regularly changing the oil, can help prevent these issues.

Some other reasons for a failing final drive motor include damage to the internal seals or bearings due to overuse or faulty installation. By carrying out regular inspections, you can catch these issues early before a catastrophic failure occurs.

Hydraulic Systems Malfunctions

The hydraulic system is a critical component of a mini excavator, providing it with ample power for scraping, digging, lifting and moving heavy loads. Given the complexity of the hydraulic system, it can be prone to malfunctions if it is not properly maintained.

Some common issues associated with hydraulic systems in mini excavators include hydraulic fluid leaks, reduced power or pressure and overheating.

To prevent these issues, the system and its components should be routinely inspected to identify and address any signs of wear or damage. Importantly, the system’s fluid levels, hoses, connectors, clamps, cylinders and seals should be inspected at least weekly as part of a preventative maintenance program.

Be sure to train your operators on general safety practices when it comes to inspecting the hydraulic system. Hydraulic fluid leaks can be extremely hazardous and cause grave injuries, so operators need to know how to stay safe while searching for them.

Undercarriage Damage

The undercarriage is an important and complex system of components that requires routine maintenance in order for your excavator to run efficiently. In particular, the undercarriage must be kept clean and free from dirt, debris, frozen mud and other contaminants that have the potential to build up and cause a range of problems. 

If left unchecked, dirt and debris can cause lasting damage to the components of the undercarriage, eventually leading to costly repairs and downtime. The accumulation of dirt and debris can also weigh down the mini excavator, making it harder to maneuver and reducing fuel efficiency.

To prevent these issues, your mini excavator’s undercarriage needs to be cleaned frequently, especially after operating it in muddy or icy conditions. As a rule of thumb, clean your mini excavator’s undercarriage after every use. Or, at least once per week if the machine isn’t used often.

The best way to clean your machine’s undercarriage is by using a pressure washer or a hose with a jet nozzle to spray it down. If you choose to use a pressure washer, be careful not to puncture or damage any vulnerable components on the machine such as hoses. Also, avoid using harsh cleaning agents and degreasers, as these can damage the seals and other components of the undercarriage.

By regularly cleaning your mini excavator’s undercarriage, you can prolong the lifespan of the machine and avoid preventable service costs.


Mini excavators are amazing machines that can tackle some of the most challenging applications in construction, excavation and landscaping. To keep them performing efficiently, it’s important you implement a preventative maintenance program that addresses the specific needs of these great machines.

EquipmentShare has years of experience helping fleet operators successfully maintain heavy equipment such as mini excavators. Whether you need smarter tools to implement and track your maintenance programs, or you’re just looking to quickly purchase mini excavator parts online, we can help you keep your mini excavator up and running.

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