Before buying an excavator at auction, it’s important to consider how the machine will be used. Narrowing down your search to a size appropriate for the scope of projects you’ll be undertaking will help save you money in the long run.
Ensure the excavator’s frame is free from significant dents and excessive scuffing. Damaged frames can indicate a lack of care.
Hydraulic Cylinders
The hydraulic cylinders on a used excavator for sale are crucial to power the machine’s movements. These cylinders have multiple sleeves that extend when hydraulic pressure is applied. The larger sleeve called the barrel, is developed first, and then each subsequent sleeve is opened when the pressure continues to be used.
As the cylinders move, they return feedback to the controller, which can read these signals and alter their movement accordingly. The controller can even change the stroke pattern based on the different types of tasks the machine is performing.
Request plenty of pictures and video footage if you’re looking at a used excavator a long drive away. This will allow you to get a close-up of critical pieces of equipment and can be just as effective as a personal visit. Inspect all the fluids, especially the engine oil, machine coolant, and hydraulic liquids.
Please make sure they’re clean and free of sediment buildup. Engine coolant that appears muddy or green may indicate a cooling system issue, and hydraulic fluid with varying viscosity could also indicate problems. Also, open up the final drives to inspect their condition. Look for metal shavings in the lubricant and listen for grinding or clicking noises, which may signal that their bearings are wearing out.
Final Drives
Whether integrated into the excavator’s hydraulic motor or as separate gear hub and hydraulic motor components, final drives are key to powering an excavator. These highly engineered elements are excellent at transferring propulsion but are also very susceptible to excessive wear when the machine operates beyond capacity.
This is why it’s important to check the final drive oil level, look for signs of excessive wear, and have it tested (see below). The best way to determine an excavator’s condition and potential for future issues is to ask about its history and application. Compare it to similar makes and models in the same size class selling at auction or new.
Look for a consistent price trend and factor in machine hours to see how well the excavator was maintained by its previous owner. Aside from examining the undercarriage and asking about its history, a qualified mechanic should inspect the machine’s final drives, hydraulic tank, and slewing ring for leaks.
Hydraulic leaks aren’t just a nuisance; they can indicate poor maintenance and serious mechanical problems. Leaks from the final drive, gearbox, and hydraulic system are all signs of failure or neglect that require immediate attention. It would help if you also had the hydraulic fluid sampled and analyzed for grit to detect signs of trouble in the planetary gears and other systems.
Slewing Ring
While some blemishes are expected on used excavators, examine the undercarriage for signs of excessive wear and tear. Heavy wear to tracks, cab, and buckets may indicate that the machine needed to be cared for properly by the previous owner and could result in future maintenance costs.
Examine all connection points, such as those between the boom and bucket, to ensure they are tight and secure. Look for cracks, looseness, or other damage that would compromise the function of these critical parts. Also, check the slewing ring to ensure it is free from unusual movement. A damaged slewing call can cause the drive-plate coupling to lose alignment.
This can lead to vibration and damage to other equipment. Inspect for signs of a broken or missing slewing ring pin and damage to the bearings and slewing gear. If you are still getting familiar with the brand of excavator you are considering buying, research ahead of time to find out its reputation for reliability and durability.
It’s also worth looking at the maintenance history of the maintenance machine to see if it was regularly serviced and if any major issues were addressed. Identifying potential problems before they occur can save you money in the long run by reducing downtime and the need for replacement parts that aren’t easily available.
Pivot Points
The pivot points on an excavator are exposed to extreme stress and must move smoothly. A snag in one of these areas could lead to reduced performance and costly repairs. Check for excessive wear, pins separating or stuck in place, misalignment, jagged movement, and other problems. Examine the pivot point areas on a machine in person to see their condition for yourself.
If not, request plenty of pictures and even the machine’s motion video. Reputable sellers are happy to provide this digital proof to help you feel confident in your used excavator purchase.
Other important areas to evaluate are the cab, boom, and bucket. Look for welds that look out of place or were made after the machine was built (indicating repairs). Also, look for dents, cracks, and other damage. A well-maintained excavator should exhibit minimal wear and tear.
Final Words
Lastly, ensure that any attachments you want to use will be included with the machine. Adding a ripper, digging bucket, or other specialized equipment can drastically increase productivity. Check that these are in good working condition and appropriate for the size of the excavator.
When selecting a specific used excavator at auction, consider how you will use it and what features are most important to your work. For example, if safety is a top priority, choose a model that prioritizes operator comfort with maximum cab visibility, fire suppression, and operation restraint systems.
