If you're looking at buying a Komatsu PC75UU-2, there are a few key areas I'd always inspect before handing over money. These machines can be solid, but repairs get expensive quickly if the previous owner neglected maintenance.
1. Engine condition
Start with the basics. Check for hard starting, excessive smoke, or knocking. The PC75 series usually runs a small turbo diesel, and issues like clogged injectors, overheating, or poor maintenance can reduce power or increase fuel consumption. Look for oil leaks, check the coolant, and make sure it runs smoothly under load.
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2. Hydraulic system performance
Hydraulics are one of the most expensive systems to fix. Run the machine and test all functions (boom, stick, bucket, swing, travel). Watch for slow response, jerky movements, or whining from the pump. Also check hoses and cylinders for leaks and inspect the hydraulic oil condition. Contaminated fluid or worn seals can lead to pressure loss and poor operation.
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3. Undercarriage wear
Tracks, rollers, sprockets, and idlers can cost thousands to replace. Look for uneven wear, loose track tension, cracked rollers, or worn sprockets. Undercarriage wear is common on older compact excavators, so this is a big negotiating point if it's near the end of life.
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4. Pins, bushings, and boom structure
Check the boom, stick, and bucket pins for excessive play. Grab the bucket and move it side to side - if there's a lot of slop, it likely needs a pin and bushing job. Also inspect welds and structural areas for cracks or repairs, especially around the boom base and swing area.
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5. Swing motor and slew ring
Rotate the upper structure slowly and listen for grinding or clunking. Excess noise or jerky rotation can mean a worn slew bearing or swing motor problems, which are costly repairs.
Overall, if the engine runs strong, hydraulics feel tight, and the undercarriage isn't worn out, the PC75UU-2 can still be a very useful compact excavator.