How Old Is Too Old for a Full-Size Excavator

[MikePhua]

The Economics of Ownership vs Rental
For contractors and landowners who frequently rent full-size excavators, the tipping point often comes when rental costs begin to rival the price of ownership. Spending $4,000 or more in a single month to rent a 20-ton class machine (typically in the 150–200 size range) can prompt serious consideration of buying used. But with used machines often clocking 5,000 to 8,000 hours, the question arises: when does age become a liability?
Excavators in this class—such as the Caterpillar 320, Komatsu PC200, or Hitachi ZX200—are built for durability. Many reach 10,000 to 15,000 hours before major component failures, provided they’ve been maintained properly. However, age affects more than just the hour meter. Rubber components, seals, hoses, and electrical connectors degrade over time, even if the machine hasn’t been heavily used.
Hydraulic Hose Longevity and Replacement Costs
Hydraulic hoses are often the first components to show age. After 6–7 years, even low-hour machines may develop leaks due to hardening of the outer jacket or internal cracking. Hoses that flex frequently—such as those on the boom, stick, and bucket—are especially vulnerable.
Signs of aging hoses:

• Surface cracking or “checking”
  
• Oil seepage through the outer jacket
  
• Flattened or hardened O-rings
  
• Weeping at crimped ends
  

Terminology:

• Checking: Small surface cracks caused by UV exposure and aging.
  
• Weeping: Slow leakage of fluid that doesn’t form droplets but leaves a greasy film.
  

Replacement costs vary. A full hose set for a 20-ton excavator can exceed $5,000 in parts alone, with labor adding another $2,000–$3,000 depending on access and routing. However, hoses are not the most expensive concern.
Structural Integrity and High-Risk Components
When evaluating older excavators, structural components deserve closer scrutiny than hoses. Cracks in the carbody, boom welds, or swing bearing mounts can signal fatigue or past abuse. These repairs are costly and often require disassembly or welding in confined spaces.
High-risk areas:

• Boom-to-stick welds
  
• Carbody center frame
  
• Swing bearing and gear teeth
  
• Final drives and planetary gears
  

Terminology:

• Carbody: The main structural frame of the excavator, connecting the upper and lower assemblies.
  
• Swing Bearing: A large bearing that allows the upper structure to rotate; failure here can be catastrophic.
  

A contractor in Indiana once purchased a 10,000-hour excavator for $35,000, only to discover a hairline crack in the swing bearing mount. The repair required removing the entire upper structure and cost nearly $12,000. Lesson learned: always inspect structural welds and listen for unusual noises during rotation.
Undercarriage Wear and Hidden Costs
The undercarriage is another area where age shows. Track chains, rollers, sprockets, and idlers wear gradually, but once they reach critical thresholds, replacement becomes unavoidable. A full undercarriage rebuild on a 20-ton machine can cost $10,000–$15,000.
Inspection tips:

• Measure track chain pitch with calipers
  
• Check roller flanges for thinning
  
• Inspect sprocket teeth for hooking
  
• Look for uneven wear on pads and links
  

Terminology:

• Pitch: The distance between track chain links; excessive pitch indicates wear.
  
• Hooking: Curved wear on sprocket teeth that reduces engagement and increases slippage.
  

In one case, a buyer in Missouri found a machine with 7,500 hours and a clean engine—but the undercarriage was at 80% wear. He negotiated a $7,000 discount and used the savings to rebuild the tracks, extending the machine’s life by another 3,000 hours.
Engine and Hydraulic System Considerations
Engines in older excavators are often reliable if maintained, but hydraulic pumps and valve blocks can be expensive to rebuild. A main pump failure can cost $8,000–$12,000, while valve block replacements may run $4,000–$6,000.
Best practices:

• Pull oil samples from engine, hydraulics, and finals
  
• Scan for fault codes if the machine has electronic controls
  
• Listen for pump whine or erratic cylinder movement
  
• Check for slow swing or travel response
  

Terminology:

• Oil Sampling: A diagnostic method that analyzes fluid for wear metals, contamination, and viscosity breakdown.
  
• Pump Whine: A high-pitched noise indicating cavitation or internal wear in hydraulic pumps.
  

A fleet manager in Alberta used oil sampling to detect early pump wear in a 6,800-hour Komatsu PC200. By replacing the pump proactively, he avoided a jobsite failure and kept the machine in rotation for another two years.
Buying Strategy and Inspection Protocol
When shopping for older excavators, the key is to prioritize structural integrity and component history over cosmetic appearance. Machines with faded paint and worn seats may still be mechanically sound, while freshly painted units can hide serious flaws.
Recommended steps:

• Visit the machine on a jobsite and observe it under load
  
• Let the owner operate it while you watch and listen
  
• Ask for service records, especially for pump, finals, and swing bearing
  
• Budget for immediate hose replacement if the machine is over 7 years old
  

Terminology:

• Final Drives: Gear assemblies that transmit power from the travel motor to the tracks.
  
• Service Records: Documentation of maintenance and repairs, critical for assessing machine history.
  

Conclusion
There’s no fixed age at which an excavator becomes “too old”—but there are clear signs when age begins to outweigh value. Machines with 6,000–8,000 hours and 7–10 years of service can still be excellent investments if inspected thoroughly and priced appropriately. Hoses and seals are manageable; structural cracks, swing bearing wear, and undercarriage failure are deal-breakers unless deeply discounted. With a sharp eye and a methodical approach, older excavators can deliver thousands of productive hours without breaking the bank.