Introduction
You've just purchased a used excavator from a Chinese yard, or you're about to. The machine is a 2018 Komatsu PC200-8 with 6,200 hours, graded B, priced at USD 48,500 FOB Shanghai. Or maybe it's a 2019 Doosan DX225LC with 5,800 hours, also grade B, at USD 42,000 FOB. Either way, the next 90 days determine whether that machine delivers five years of service or becomes a money pit. This guide gives you six maintenance steps, grounded in how ExcaYard prepares machines and what third-party inspectors from SGS, Bureau Veritas, and Intertek actually check. Each step includes what to do, why it matters, and how to avoid the most common post-import failures.
Step 1: Baseline the Machine Before It Leaves the Yard
Before shipment, you need a complete maintenance baseline. That means recording current engine hours, hydraulic pump pressure, undercarriage percentage, and any active fault codes. Request the 150-point inspection report, which covers serial number, engine, hydraulics, undercarriage, boom and arm, bucket, cab, electrical system, fluid leaks, and test operation. The deliverables should include a photo set, video walkaround, condition grade, repair notes, and loading readiness. If you're buying a medium excavator (20-30 tons), pay special attention to engine hours, undercarriage percentage, hydraulic pump pressure, and boom and arm cracks. For a large excavator (35+ tons), focus on structural welds, slew bearing, track frame, cooling system, and transport dimensions. For mini excavators (1-8 tons), check hydraulic leaks, swing play, track wear, and attachment pins. Without this baseline, you cannot track degradation or prove pre-existing conditions to your insurer.
Step 2: Establish a Fluid and Filter Schedule Based on Hours and Grade
Once the machine arrives, change all fluids and filters unless you have documented proof they were replaced within the last 250 hours. This includes engine oil, hydraulic oil, coolant, and fuel filters. For a grade B machine like a 2017 CAT 320D with 7,100 hours, assume the hydraulic oil has 2,000+ hours unless the inspection report states otherwise. Use OEM-specified fluids. For Komatsu PC200-8, PC220-8, PC240LC-8, PC300-8, and PC360-7 models, use Komatsu-specified hydraulic oil and engine oil. For Doosan DX225LC, DX300LC, DX380LC, DH225LC, and DH420LC, follow Doosan's fluid recommendations. For CAT 320D, CAT 320D2, CAT 323D, CAT 336D, and CAT 349D, use CAT-specified fluids. Then set a schedule: engine oil every 500 hours, hydraulic oil every 2,000 hours (or annually), coolant every 2,000 hours, and fuel filters every 500 hours. If you operate in high-dust environments like the Middle East, halve those intervals. In Kenya, where machines often work in quarry and infrastructure projects, stick to the standard intervals but check air filters weekly.
Step 3: Inspect and Maintain the Undercarriage Weekly
The undercarriage is the most expensive wear component on any excavator. A new track group for a 20-ton machine can cost USD 8,000-12,000. For a used machine, you want to measure track tension, bushing wear, sprocket teeth, and idler condition every 250 hours. For medium excavators, undercarriage percentage is a key inspection focus. If your machine arrived at 60% undercarriage, you have roughly 2,000-3,000 hours before replacement. For large excavators, track frame and structural welds matter more. For mini excavators, track wear and swing play are critical. In sandy environments like the Middle East, undercarriage wear accelerates. Buyers in UAE, Saudi Arabia, Oman, and Qatar should check hydraulic hose condition and sand/dust wear as part of a weekly routine. In Kenya, buyers should check undercarriage condition and maintenance records where available, and plan for Mombasa clearance delays that can leave machines sitting in salt air. A simple weekly walkaround: check track tension, look for oil leaks around final drives, and inspect sprocket teeth for sharp edges.
Step 4: Monitor Hydraulics and Cooling System Under Load
Hydraulic pumps and cooling systems fail under heat and contamination. After every 500 hours, take hydraulic oil samples and send them for analysis. Look for iron, copper, and silicon levels. If silicon is high, you have dirt ingress. If iron is high, you have pump or motor wear. For high-temperature regions, the cooling system is your first line of defense. Middle East buyers must verify high-temperature cooling condition and air-conditioning system function before purchase, then maintain them monthly. Clean the radiator and oil cooler fins with compressed air or low-pressure water every 250 hours in dusty conditions. Check hydraulic hoses for cracking and abrasion. A blown hose on a 30-ton machine can cost USD 500-1,500 in parts and lost production. For large excavators, cooling system is a specific inspection focus. For medium excavators, hydraulic pump pressure is a key metric. If pressure drops more than 10% from baseline, investigate immediately.
Step 5: Document Everything for Compliance and Resale
Maintenance records are not just for you; they are for customs, insurers, and future buyers. Keep a log of every fluid change, filter replacement, and repair. Include dates, hours, parts used, and technician name. This log supports your export document pack, which includes commercial invoice, packing list, bill of lading, certificate of origin, China customs export declaration, inspection report, serial-number photos, and insurance document if CIF. Note that document names and destination requirements should be confirmed with your clearing agent. For Kenya, buyers need KEBS/PVoC review. For Middle East, buyers need to confirm destination charges. If you ever resell the machine, a complete maintenance history can add 10-15% to resale value. It also helps with warranty claims if you bought a grade A machine with a limited warranty. Use a simple spreadsheet or a maintenance app; the format matters less than consistency.
Step 6: Plan Major Component Replacements by Grade and Hours
Every used excavator has a finite component life. Use your grade and hours to plan. Grade A: clean condition, low visible wear, strong operation record. You likely have 3,000-5,000 hours before major components. Grade B: normal used condition with moderate wear. Plan for hydraulic pump rebuild at 8,000-10,000 hours, undercarriage at 6,000-8,000 hours, and engine overhaul at 12,000-15,000 hours. Grade C: working machine needing visible repair or refurbishment planning. You should budget for immediate repairs. For a 2016 CAT 336D with 9,500 hours, grade B, expect to replace undercarriage within 1,000 hours. For a 2018 Komatsu PC300-8 with 7,200 hours, grade B, check slew bearing and track frame. For a 2019 Doosan DX380LC with 6,800 hours, grade B, monitor hydraulic pump pressure. Set aside 10-15% of the purchase price annually for maintenance and repairs. That is USD 4,200-6,300 per year on a USD 42,000 machine.
What to Do Next
Start with Step 1 today. If your machine is still in the yard, request the 150-point inspection report and a third-party verification from SGS, Bureau Veritas, or Intertek. If it has arrived, baseline your fluids, filters, and undercarriage within the first 48 hours. Then set a weekly and monthly maintenance calendar based on your operating environment. For buyers in Kenya, review KEBS/PVoC requirements and plan Mombasa clearance. For buyers in the Middle East, prioritize cooling system and hydraulic hose checks. For all buyers, keep a maintenance log and plan major replacements by grade and hours. A used excavator is a capital asset; treat maintenance as a profit center, not a cost. For more details on machine preparation and export documentation, visit ExcaYard.com.