The Caterpillar 320 series has long been a benchmark in the mid-sized excavator market. From the legendary 320D to the modern Next Gen models, these 20–22 ton machines are prized for their durability, powerful hydraulics, and strong resale value. For contractors seeking a reliable used excavator, the Cat 320 is often at the top of the list—competing directly with models like the used Komatsu PC200, used Hitachi ZX200, and used Volvo EC210.
However, not all used Cat 320s are equal. A machine that has spent its life in light municipal work will look very different from one that has endured years in mining or heavy demolition. Knowing what to inspect can mean the difference between a smart investment and a costly repair project.
This guide presents five critical inspection tips for evaluating a used Caterpillar 320 excavator. Whether you’re a first-time buyer or an experienced fleet manager, these tips will help you make a confident, data-driven decision.
Tip 1: Cold Start Engine Inspection
The engine is the heart of any used excavator, and for the Cat 320, it’s typically a Caterpillar C4.4, C6.4, or C7.1 depending on the series (320D, 320E, Next Gen). A thorough cold start inspection can reveal hidden issues that warm-up might mask.
What to Look For:
Cold Start Behavior: Request that the machine be left untouched before your inspection. A healthy Cat 320 should start within a few seconds of cranking. Observe the exhaust:
- Brief black smoke during startup is normal.
- Persistent black smoke indicates incomplete combustion—often due to clogged air filters, faulty injectors, or turbocharger issues.
- Blue smoke signals burning oil—a sign of worn piston rings, valve seals, or turbocharger seal failure.
- White smoke that continues after warm-up suggests coolant entering the combustion chamber—potentially a blown head gasket.
Idle Stability: Once started, the engine should idle smoothly without fluctuating RPMs. Listen for knocking, ticking, or metallic noises.
Under Load Performance: After reaching operating temperature, test the engine under hydraulic load. According to user feedback, the Cat 320 “has good grunt” and “never feels underpowered digging hard clay” . If the engine bogs down, suspect fuel system or turbocharger problems.
Competitor Context:
- Used Komatsu PC200: Often praised for fuel efficiency and hydraulic smoothness, but some users note it lacks the “grunt” of a Cat.
- Used Hitachi ZX200: Known for fast cycle times but reported by some operators to have higher long-term maintenance costs.
- Used Volvo EC210: Offers excellent cab comfort and safety, but resale value typically lags behind Cat.
Tip 2: Hydraulic System Function Test
The Cat 320’s hydraulic system is engineered for power and precision. Hydraulic component repairs are among the most expensive on any used excavator, making this inspection critical.
What to Look For:
Visual Inspection: Walk around and inspect all hoses, cylinders, and connections:
- Wet spots or drips around fittings
- Kinked, chafing, or bulging hoses
- Cylinder rods with scoring, pitting, or chrome peeling—damaged rods will tear cylinder seals
Function Testing: With engine at operating temperature, test:
- Boom up/down
- Arm (stick) in/out
- Bucket curl/dump
- Swing left/right
- Travel forward/reverse
Smooth, responsive movement without jerking or hesitation indicates a healthy system.
Hydraulic Drift Test: Position the bucket with arm extended and engine off. A small amount of drift is normal, but rapid drift (arm dropping significantly within minutes) indicates internal cylinder seal leakage or valve wear.
Listen for Unusual Noises: Whining or grinding during operation can indicate pump cavitation or internal wear.
Real-World User Insight:
One operator noted, “Hydraulics are smooth enough, I didn’t run into annoying lag or weird noises which you sometimes get with beat-up machines” . This aligns with the 320’s reputation for reliable hydraulic performance.
Tip 3: Undercarriage and Structural Integrity
Undercarriage wear is one of the largest variable costs in owning a used excavator. A full undercarriage replacement can run $5,000–$10,000. Structural cracks can be even more expensive—or render the machine unsafe.
What to Look For:
Track Chains: Measure track sag between the carrier roller and track shoe. Excessive sag indicates chain stretch. Also inspect for:
- Rust between bushings (indicates prolonged sitting)
- Worn or broken track links
- Missing track shoes or bolts
Sprockets and Idlers: Drive sprockets with sharp, hooked teeth indicate advanced wear. Front idlers should show no excessive wear or leaking seals.
Rollers: Check all bottom and carrier rollers. Rollers that don’t turn freely (seized bearings) or show flat spots need replacement. Oil leaks from rollers indicate seal failure.
Track Frame and Main Frame: Inspect the track frame for cracks or welding repairs—especially around the turntable connection. Cracks here can indicate overloading or accident damage.
Boom and Arm: Inspect all pivot points for excessive play. Check weld joints at stress points—particularly where the boom attaches to the frame and where the arm attaches to the boom.
Undercarriage Wear Benchmark:
If you can see significant wear on track chain bushings (flattening), the undercarriage likely has less than 50% life remaining. Track tension should be within manufacturer specs—too tight accelerates wear; too loose risks derailment.
Tip 4: Operational Functions and Cab Evaluation
The operator’s daily experience directly impacts productivity. A machine with failing controls or an uncomfortable cab will cost you in efficiency.
What to Look For:
Travel Test: Drive the machine forward in a straight line. If it consistently veers without steering input, there may be hydraulic imbalance or final drive issues.
Swing Function: Swing should be smooth in both directions. Grinding or hesitation can indicate swing bearing wear or swing motor issues.
Brake Test: On a grade, the machine should hold position without drifting.
Cab Ergonomics: Sit in the operator’s seat and evaluate:
- Seat condition and adjustability
- Joystick responsiveness and button functionality
- HVAC operation—working air conditioning and heat
- Gauges and warning lights—all should function
User Feedback on Cab Comfort:
One operator noted that the Cat 320’s cab is “solid, especially the new seat—not bad on long shifts, though the AC could be stronger for hotter days” . Another mentioned, “It’s not the most comfy cab if you’re running 10+ hours. It’s fine but your back notices by the end of the week” .
Next Gen Considerations:
If inspecting a Next Gen Cat 320 (2020+), note the keyless start system. One user observed, “First thing I noticed was no key, just a code and button to start. Not sure I love all the gadgets but the basics work” .
Tip 5: Documentation and Hour Meter Verification
The most overlooked aspect of buying a used excavator is verifying its history. Inconsistent documentation can indicate tampering or hidden damage.
What to Check:
Service Records: Request full maintenance logs. Look for consistent service intervals—oil and filter changes, hydraulic filter replacements, and major component overhauls. A documented service history is a strong indicator of responsible ownership.
Hour Meter Consistency: Cross-reference displayed hours with physical wear indicators:
- Pedal rubber wear (should match hours)
- Seat condition (original vs. replaced)
- Joystick wear
- Paint fade on high-touch areas
If the machine shows 4,000 hours but pedals are worn smooth and the seat is heavily cracked, the meter may have been tampered with.
Usage History: Ask about previous applications. A machine used in landscaping or municipal work will have less stress than one used in mining or rock quarry applications.
Major Repairs: Ask whether the engine, hydraulic pump, swing motor, or final drives have been rebuilt. Documented rebuilds with quality parts can extend machine life; undocumented repairs should be treated with caution.
Red Flags:
- 🚩 Excessive welding or poorly executed repairs—indicates structural damage
- 🚩 Inconsistent hours—worn pedals but low meter hours
- 🚩 Fluid contamination—milky oil (water) or metallic sheen (internal wear)
- 🚩 Missing service records—a well-maintained machine will have documentation
Market Context: Pricing and Comparisons
According to recent listings, a used Caterpillar 320D with 6,000–8,000 hours typically ranges from $31,000 to $45,000 depending on condition and attachments . A Next Gen Cat 320 (2020+) with lower hours can command $85,000–$120,000.
Competitor price benchmarks:
- Used Komatsu PC200-8: Typically 5–10% below comparable Cat models
- Used Hitachi ZX200: Often 10–15% less than Cat
- Used Doosan DX225: Positioned as a value option, 15–20% below Cat
Conclusion: Inspect Smart, Invest Wisely
The Caterpillar 320 has earned its reputation through decades of reliable performance. From the legendary 320D to the advanced Next Gen models, these machines deliver the power, durability, and resale value that contractors trust. However, a used excavator is only as good as the inspection behind it.
By following these five critical inspection tips—cold start engine evaluation, hydraulic system testing, undercarriage inspection, operational function testing, and documentation verification—you can confidently assess any used Cat 320 and avoid costly surprises.
Your Trusted Partner for Used Caterpillar Excavators: Taihongmachinery
At Taihongmachinery (TH Engineering Equipment Limited) , we specialize in connecting international buyers with high-quality used Caterpillar excavators, including the popular Cat 320 series. With years of experience serving buyers across Africa, the Middle East, Southeast Asia, and Latin America, we understand what it takes to deliver reliable equipment you can trust.
Why Choose Taihongmachinery:
- Curated Inventory: We carefully inspect every used Caterpillar excavator before listing—verifying hour meters, component wear, and operational condition against OEM standards.
- Transparent Condition Reports: We provide detailed photos, videos, and honest assessments—including engine start-up videos, hydraulic function tests, and undercarriage wear measurements.
- Third-Party Inspections Welcome: We encourage buyers to arrange independent inspections through SGS, Bureau Veritas, or other agencies.
- Competitive Pricing: Our direct sourcing channels allow us to offer fair market prices—typically 15–25% below dealer retail.
- Full Export Support: From documentation to shipping coordination, our logistics team handles the complexities.
- After-Sales Assistance: Even after your used excavator arrives, we’re here to help with parts sourcing and technical support.
Whether you’re searching for a dependable used Cat 320D, a modern Next Gen 320, or comparing against used Komatsu PC200, used Hitachi ZX200, or other brands, Taihongmachinery has the expertise and inventory to meet your needs.
Ready to find your used Caterpillar 320? Contact our team today for personalized assistance and transparent pricing.
