Service History: Request maintenance records to verify regular servicing. Lack of documentation may indicate neglect.

Structural Integrity: Inspect the boom, arm, and undercarriage for cracks, rust, or weld repairs. Misaligned tracks or excessive wear suggest heavy use.

Hydraulic System: Check for leaks, slow movements, or unusual noises during operation. Replacing hydraulic pumps can be costly.

Engine Hours: Compare hours to the model's typical lifespan. Cat excavators often last 10,000+ hours with proper care.

Seller Reputation: Buy from dealers with verified reviews or OEM-certified resellers. Avoid auctions with no inspection access.