Many owners and operators think of their mini excavator as more of a toy than a piece of construction equipment due to its diminutive size, but these machines require the same maintenance and care that their larger counterparts require. With all the same components of larger machines, they can be just as expensive. Without proper maintenance, mini excavators will not provide the dependable performance required on the jobsite, and the machine’s service life will be greatly reduced. Regardless of the manufacturer, many failures can be traced back to a lack of proper maintenance.
One of the most overlooked service points on mini excavators is track tension. Most mini excavators have rubber tracks, which must be kept properly adjusted to maximize longevity and minimize wear on the track and its components. A track running loose will accelerate wear, causing unnecessary downtime and putting a stop to production for the reinstallation of a new track. On the other hand, a track running too tight will cause the rubber material to tear and will greatly increase wear on the other track system components, including traction motors, sprockets and front idlers. Operators should always refer to the operator’s manual and check track sag measurements on a regular basis to ensure the track tension is correct.
The lifeblood of all pins and bushings, grease is another service point operators often forget about. As a general rule, operators should grease all pins and bushings daily. The operator’s manual will identify each grease point and provide recommendations for quantity and grade of grease. If multiple operators are using a single machine, you should mark less obvious grease points, such as the turntable bearing, with orange marking paint around the grease nipple to remind all users to perform this task.
As with under-greasing, over-greasing can also be problematic. One to three shots of grease is typically more than enough to do the job. Any extra, and it becomes a waste of money, presents an environmental hazard and causes a considerable mess.
The propel drive gearbox, one of the most vital components of a machine’s performance, is often neglected when it comes to servicing. Oftentimes, gearboxes are covered in mud, with the fill and drain plugs not visible, so operators and service personnel rarely notice them. However, gearboxes require an oil change at approximately 1,000-hour intervals, depending on the manufacturer. Many of these propel gearboxes from some manufacturers fail at 1,500 to 3,000 hours, and once removed and drained, the oil is commonly burnt and degraded to the point that it can no longer protect the moving parts inside. Gearboxes may be small, but they are still expensive to manufacture because they have the same internal parts as their larger cousins, just on a smaller scale. Typically holding between one-half to one quart of oil, gearboxes can be changed quickly in most cases, so this maintenance step is a small investment that will pay off in the future.
Countless machines have never had a hydraulic oil change. Hydraulic oil can be misleading because, although it may look clean (just like engine oil), it breaks down and loses its viscosity and its ability to hold contaminants in suspension, a process that helps protect all moving parts in the system. Hydraulic systems are designed for precise tolerances, and most hydraulic failures can be traced back to contaminated hydraulic oil or even the wrong type of hydraulic oil.
One of the many important functions of hydraulic oil is that it absorbs moisture in the system and keeps it away from the hydraulic components. You may not think that rust could be a problem in a sealed hydraulic system that is always full of oil, but it is. I have disassembled failed hydraulic pumps and hydraulic system components and have found rust on the rotating group and in the housings. Don’t make the mistake of thinking that, just because hydraulic oil looks good, it is. By the time hydraulic oil becomes cloudy, it is far beyond the point when it should have been changed and has lost much of its ability to properly protect the components in the hydraulic system. Most equipment manufacturers suggest a hydraulic oil change interval in the 2,000- to 4,000-hour range, but every machine is different. Your operator’s manual will provide a specific servicing timetable and oil requirements.
Lastly, record keeping may the most tedious and time-consuming of all tasks, but keeping service records and invoices for oil, filters and repairs up-to-date can provide invaluable information in the future when evaluating the service life of your machine. All equipment will come to the end of its service life eventually, and if you keep accurate information, you will have a baseline to evaluate the performance of the machine and make an informed decision about whether to buy the same manufacturer’s product again or make a switch to a different brand.
Proper service records are also helpful when working with your dealer if an issue with your machine arises. Accurate records will prove to both your dealer and the manufacturer that you care about your equipment and that you are servicing the machine as required. This principle can be crucial when dealing with warranty claims and is necessary whether you have an entire fleet of mini excavators or just a single machine.
Next time you service the engine oil and fuel filter on your mini excavator, check your operator’s manual, take a little extra time and money to service your machine properly and always document the service. These maintenance habits are the most cost-effective ways to ensure minimal downtime in the future. In the long run, you and your bottom line will be glad you did.