Used Excavator Inspection Checklist: 50-Point Field Guide for International Buyers

When you are buying a used excavator from China — whether through ExcaYard, another exporter, or directly from a yard — you (or your inspector) need a checklist. Trust comes after verification, never before. This guide gives you the 50 points we actually run on every machine before listing it, plus the red flags that should make you walk away.

You can use this for your own physical inspection if you can travel to China. If not, the same list works as a question set: ask the seller to provide photos and measurements against each point. Their reaction tells you more than the answers.

Before you start: hours and serial verification

Verify the machine before touching it. Pull the hour meter reading and the engine ECM reading separately — if they don’t match, that’s a red flag. Photograph the serial number plate, write it down, and cross-reference it against the OEM service records if available.

For Cat machines, the Cat ET diagnostic tool pulls ECM data including total hours, fault history, and recent operator behavior. For Komatsu, KomNet does the same. Hitachi has Diagnostic Assistant. If the seller can’t or won’t connect a diagnostic tool, that is by itself a red flag.

Engine — 12 checkpoints

1. Cold start behavior: machine sat overnight, cold engine. It should start within 5-10 seconds without excessive cranking. White smoke for a few seconds is normal; sustained blue smoke is not.
2. Idle stability: at warm idle, the engine should hold steady RPM without surging or rough running.
3. Exhaust at full throttle: under load, exhaust should be near-clear. Heavy black smoke = injector or air filter problem. Blue smoke = oil burning. White smoke at operating temperature = head gasket or coolant problem.
4. Engine oil: pull the dipstick. Oil should be amber-brown, not milky (water contamination) or jet-black-and-thick (overdue service).
5. Oil filler cap underside: look for creamy residue — indicates coolant in the oil, very bad.
6. Coolant: should be the correct OEM colour, not rust-coloured or with floating debris.
7. Coolant reservoir level: should be at the cold-fill line.
8. Belt condition: alternator and fan belts should not have visible cracks or fraying.
9. Hose condition: all coolant and oil hoses should be supple, not brittle or bulging.
10. Listen for unusual noises: knocking, hissing, or rattling under acceleration.
11. Engine bay leaks: check the bottom of the bay and beneath the machine — wet patches or oil drips are a problem.
12. Air filter housing: open it. The element should be clean (or recently replaced); heavy dust caking means the filter is overdue.

Hydraulic system — 10 checkpoints

13. Cycle times: boom up, boom down, stick out, stick in, swing 180°. Each operation should complete within the OEM published times for the machine class (typically 4-7 seconds depending on size). Slow cycle = worn pump or relief valves.
14. Smooth response: stick movements should be progressive, not jerky. Erratic response under partial load indicates pilot or main valve issues.
15. Cylinder rod condition: every hydraulic cylinder rod — boom, stick, bucket — should be visually mirror-smooth and dry. Scratches, pitting, or weeping oil indicate seal failure or impending failure.
16. Hose and fitting leaks: walk around the machine after working it for 10 minutes. Any wet patches around connections are leaks.
17. Hydraulic oil sample: open the reservoir cap. Oil should be amber-clear, not dark brown or with visible particulates. A dark oil sample suggests overdue service or contamination.
18. Oil level: hot oil at operating temp should read between the marks on the sight gauge.
19. Drift test: park with boom fully raised, engine off, leave 30 minutes. The boom should not drop more than 2-3 cm. Significant drop = internal cylinder leak.
20. Pressure relief test: stall the bucket curl against the ground at full throttle. Relief should engage smoothly, not bang or chatter.
21. Auxiliary hydraulics: if equipped (for breakers, thumbs, etc.), test the aux circuit at full pressure.
22. Tracking straightness: drive the machine straight on flat ground. If it pulls left or right, one final drive is leaking or one swing motor is weak.

Undercarriage — 9 checkpoints

The undercarriage is the most expensive used-excavator wear item. A full undercarriage rebuild on a 20-ton class machine runs $8,000-15,000.

23. Track chain stretch: measure the pitch (centre-to-centre distance) over 5 links. Compare to OEM new spec. More than 4% stretch = chain needs replacement.
24. Sprocket teeth: should be triangular and crisp. Rounded, hooked, or visibly worn teeth mean replacement.
25. Idler condition: front idler tread should be flat. Cupped or dished idlers indicate misalignment or end-of-life.
26. Track rollers: bottom rollers carry the machine weight. Each should spin freely (machine on blocks or with track raised). Frozen rollers = bearings gone.
27. Carrier rollers: top rollers — should also spin freely.
28. Track shoe condition: shoes should be intact, not cracked or broken. Check for stretched bolt holes.
29. Track tensioner: should hold tension. Grease cylinder hold-firm — sagging tracks indicate failed tensioner.
30. Track frame welds: visually inspect for crack repairs or new welds. Fresh weld marks indicate prior structural damage.
31. Final drive housing: look for oil leaks at the seal between final drive and chassis. Final drive leaks are a serious red flag.

Swing & rotation — 4 checkpoints

32. Slew bearing play: push and pull the boom laterally with the engine off. Any audible click or felt play means the slew bearing is wearing — a 4-figure expense.
33. Swing motor noise: slew the machine 360° slowly. Should be smooth without grinding.
34. Swing brake: engaged brake should hold the machine still on a slight slope.
35. Slew bearing grease: check the grease fitting — should accept fresh grease, indicating the lubrication channel is intact.

Cab & controls — 8 checkpoints

36. All gauges work: engine temperature, hydraulic temperature, fuel level, hour meter — verify each shows realistic values.
37. Joystick response: each joystick should return to centre smoothly. Sticky or off-centre = pilot valve repair due.
38. Pedal response: track pedals, swing pedal, throttle — all should return cleanly to neutral.
39. AC operation: turn on the AC, verify cold air after 2-3 minutes. AC failure is common but inexpensive to fix.
40. Heater: at idle, heater should produce warm air within 5 minutes.
41. Wipers and washer: both wiper modes, washer fluid spray. Often broken on field-worked machines.
42. Dome and work lights: all bulbs working. Check headlights, boom lights, rear work lights.
43. Seat condition: cushion and back should be intact, not torn. Operator seat replacement is $300-500.

Structural — 6 checkpoints

44. Boom welds: look for repair welds along the boom edges and joints. Honest repair welds are acceptable; hidden cracks are not.
45. Stick welds: same inspection.
46. Bucket teeth and edge: tooth-tip wear is normal; edge plate cracks or repairs are a concern.
47. Cylinder mount welds: pin mounts should be original or professionally repaired.
48. ROPS/FOPS cabin structure: should be intact. A damaged ROPS frame compromises operator safety and is usually a deal-breaker.
49. Cooler and radiator condition: external fins should be clean. Heavy plugging = overheating risk.
50. Frame condition: chassis underneath — any major cracks, repairs, or rust-through is a deal-breaker.

Common red flags — walk away signs

These are the patterns we see on machines that should never have made it to market. If you encounter any of these, walk away regardless of price.

• Hour meter recently replaced: confirmed by mismatch between meter reading and ECM data. Honest sellers disclose meter changes with full original-meter documentation. Without that disclosure, it’s odometer fraud.
• Repainted recently with hidden damage: fresh paint over crash-damaged boom or arm. Tap the area — repaired structural damage often sounds different from original metal.
• No service records and no ECM access: legitimate sellers can usually produce some service history and always allow ECM diagnostic access. Refusal of both is a signal to leave.
• Engine ECM error codes recently cleared: an ECM that shows zero historical fault codes on a 7,000-hour machine has been wiped. Honest sellers leave the history visible.
• Price significantly below market: 25%+ below comparable machines on Mascus or MachineryTrader = something is wrong. Either undisclosed damage or stolen-machine resale.
• Seller insists on inspection at a “secondary” location: not the registered yard. Often used to hide the actual condition or storage circumstances.
• Inconsistent serial number documentation: serial on the chassis plate, ECM reading, and shipping documents should all match. Any inconsistency = walk away.

When the machine passes all 50

If a machine passes all 50 points cleanly, it is genuinely a Grade A unit. Most used machines we inspect have 2-5 minor issues that we disclose in writing — a small AC leak, one worn cylinder rod, missing wipers. These are normal and priced accordingly. What you should never see is a “passes all points perfectly” machine at significantly below market price — that combination is the strongest red flag of all.

Our 150-point inspection extends this list with additional fluid analysis, ECM data extraction, and component end-of-life predictions. The summary above is what you (or your independent inspector) can verify in a single yard visit.

If you would like a 150-point ExcaYard inspection report on a specific machine in our stock or a machine you have found elsewhere, contact us. We perform third-party inspections for buyers who have identified a unit but want independent verification before purchase.