2020 CAT 345D Used Excavator 45 Ton Crawler for Sale

The 345 Series occupies a critical niche in Caterpillar‘s large excavator lineup —above the 336 (~36–38 tons) and below the 349 (~49–50 tons). This places it squarely in the “heavy production” excavator class: powerful enough for tough quarry and mining applications, yet still manageable for mass earthmoving, road construction, and heavy infrastructure projects. The 345 family encompasses multiple generations, each with its own engine technology, emission standards, and target applications.

Generation overview:

Across generations, the 345 family enjoys a reputation for durability. One UK owner of a 17-year-old 345C noted that the decision to perform a full rebuild rather than replace the machine was driven by “sustainability, cost and the company’s fondness of the excavator due to its reliability”. Aggregated owner feedback from Machineryline shows a reliability rating of 4.0/5, a maintenance rating of 5.0/5, and an operation rating of 4.0/5, with owners emphasizing the machine’s “excellent powerful engine” and that “the tracks run perfectly”.

Performance highlights:

• Gradeability. The 345 Series is capable of climbing a 70% slope, delivering excellent off-road mobility that few machines in its class can match.

• Fuel Efficiency (GC models). The 345GC increases fuel efficiency (cubic meters/tonnes per unit of fuel) up to 25% and lowers operating costs up to 30% compared to previous models, thanks to electronically controlled main pumps and a valve that ensures more work gets done with each unit of fuel.

• All-weather adaptability. Standard high-ambient temperature capability of 52° C (125° F) and 3320 m (10,900 ft) altitude capability makes the 345 series suitable for operation from the Arabian desert to high-altitude mines in the Andes.

A 2009 345D owner on Machineryline summarized the experience well: “The excavator is reliable, although not brand new. Caterpillar is excellent machinery. There is access to all important joints. The cabin is comfortable. The excavator does not fail in operation”.

While generally durable, the 345 series has documented weaknesses that used buyers should be aware of. As one comprehensive review notes: “From hydraulic issues and engine performance concerns to … these problems can lead to costly repairs and downtime”.

1. Slow Engine Speed-up & Inconsistent RPM. A known problem on the 345B L involves a non-responsive throttle knob: the engine stays at idle despite turning the knob to increase engine speed. Potential causes include a faulty throttle position sensor or a failed engine control module (ECM connection or sensor failure in the engine control circuit).

2. Dipper Stick Slow & Powerless Retraction. In a 345BL, the dipper retract motion becomes slow and powerless, often starting after the stick passes vertical and accompanied by hydraulic noise. Common causes include worn cylinder piston seals, internal leakage in the main hydraulic control valve (stick circuit), or main pump flow or pressure problems.

3. Swing Drive Seal Failure. Both swing drive boxes in a 345 are prone to leaking seals, particularly the pinion shaft lip seals. This is a known service item requiring replacement of the pinion seals and associated O-rings, with periodic lubrication and seal inspection recommended.

4. Undercarriage Wear. Undercarriage wear is a top concern. Track components (chains, sprockets, carrier rollers, track shoes, and track adjusters) are heavy wear items. On high-hour or straight-framed “UHD” models, the track frame alignment can also be a concern.

5. Hydraulic System Malfunctions. There are reports of pilot control valves sticking or failing, causing loss of pilot oil pressure and making the machine unresponsive.

6. Electrical and Sensor Failure. Solenoids (e.g., the travel speed shift solenoid) fail electrically; engine speed sensors fail, causing erratic RPM or shutdown; friction and wear on sensor probe tips require physical sensor replacement.

7. Radiator and Cooler Plugging. The radiator fins pack with dust and debris in quarry applications, leading to high coolant temperatures. It requires daily or weekly washout, not just blowing from the fan side. Degraded coolant hoses, clamps, and thermostat gaskets fail with age, causing small leaks and air locks.

8. Hydraulic Hose Abrasion. The hoses between the main control valve and the upper structure are in constant motion; without periodic rerouting or clamp replacement, they will chafe and burst. Hardened, aged hose rubber is more likely to fail under peak system pressure.

9. C13 Injector Seepage (345C/345D). A minor weep from a C13 injector’s external seal can cause fuel to leak into the engine valley, producing a fuel smell inside the cab (via the HVAC intake). The repair requires removing the injector, replacing the copper sealing washer, and re-torquing the injector hold-down clamp — moderate cost if caught early.

Key Takeaway for Used Buyers: Most of these issues are detectable with proper pre-purchase inspection — cold-start observation, full hydraulic function testing, running the machine until the oil hits operating temperature, and a thorough undercarriage and hose inspection. A machine with documented service records and clean S·O·S oil analysis is far less likely to present major surprises than a cheaper unit with unknown history.

The 345 family has relatively straightforward maintenance. The D-series transmission is hydrostatic, but the main hydraulic pumps use variable displacement axial piston units with normal service for strainers, filters, and fluid changes. For the 345GC, maintenance intervals have been extended substantially: up to 25% more fuel efficiency and up to 30% less maintenance cost compared to a 349D2 Tier 3 excavator in similar applications. This is partly due to electronically controlled pumps and a more efficient hydraulic valve to ensure more work gets done with each unit of fuel.

Key service components (common across the C13 and C9.3B) include:

• Fuel tank capacity: 600–705 L (depending on generation)

• Hydraulic system total capacity: 310–423 L

• Engine oil capacity: 32 L

• Cooling system capacity: 40 L (C9.3B) to ~50 L (C13)

• S·O·S sampling ports are standard on all fluid circuits

A full set of OEM filters for the 345C/345D includes two fuel filters and a double-element hydraulic return filter. Owners who use only genuine Cat filters report significantly longer component life than those who switch to aftermarket alternatives.

The largest routine maintenance item is the undercarriage. Track chain, sprockets, carrier rollers, and track shoes together can cost $8,000–12,000 to replace as a set. Many owners get two new or rebuilt sprockets when they replace the chains to avoid rapid new-on-old wear. Labor charges for a full undercarriage swap are approximately 16–24 machine hours depending on shop equipment.

For a high-hour unit, buyers should also budget for hydraulic pump servicing ($3,000–6,000)\ast \ast and\ast \ast finaldriveresealing($1,500–2,500) around 10,000–12,000 hours.

When evaluating any used 345 excavator, follow this protocol:

1. Verify generation, serial number, and history. Before inspecting the machine, identify its exact generation (345B, 345C, 345D, or 345GC) and serial number prefix. This determines which engine, emission tier, and hydraulic system it has. Request complete service records — engine oil changes, filter replacements, S·O·S oil analysis results, major repair invoices. Verify that the hour meter reading matches visible wear on pedals, joysticks, bucket pins, and interior panels.

2. Cold-start the engine. Listen for unusual knocking, ticking, or rough idle. Watch for excessive smoke: black = fuel system issues or air filter restriction, blue = oil burning, white = coolant leak or injector issue. Let the machine warm up fully (15–20 minutes) and monitor all dashboard warning lights — some issues only appear at operating temperature.

3. Test all hydraulic functions. Operate the machine through its full range — boom, stick, bucket, swing, and travel. The machine should respond smoothly without hesitation, whining pumps, or jerky movements. Load the hydraulics by digging into a bank or lifting the machine off the ground. Check for hydraulic drift: if the boom drops more than 1–2 inches per minute with the engine off, cylinder seals are failing.

4. Inspect the undercarriage thoroughly. Measure track sag (should be 10–30 mm between the track and carrier roller). Inspect track shoes for uneven wear patterns. Check sprockets for “hooking” (pointed tooth tips indicate imminent replacement). Examine rollers for flat spots, seized rotation, or leaking seals. Check idlers for scoring or misalignment. The undercarriage is one of the most expensive components to replace — on a 345, a full set of tracks, sprockets, and rollers can cost $8,000–12,000.

5. Check for structural cracks and weld repairs. Carefully inspect high-stress areas: boom foot (where boom attaches to the frame), boom-to-stick pivot point, stick-to-bucket linkage, and main frame near the slew bearing. Look for weld repairs that may indicate previous cracking. Fresh paint in these areas warrants closer inspection.

6. Test the electrical system and monitor. Check all dashboard indicators, gauges, warning lights, and the LCD monitor function. Test the cab HVAC system, radio, lights, wipers, and horn. Verify the backup camera works (on GC models). On earlier 345D units, also inspect the throttle position sensor input stability and ECM for any communication faults.

7. Request S·O·S oil analysis. This is the single most valuable pre-purchase test. Lab results for engine oil, hydraulic oil, and final drives reveal internal wear patterns, contamination, and fuel/coolant dilution before symptoms appear. Fine metal particles in engine oil indicate bearing wear; particles in hydraulic oil suggest pump wear.

8. Run a diagnostic scan (if possible). For the 345C and 345D, connecting Cat ET diagnostic software reveals active or logged fault codes that may not trigger dashboard warnings — including engine derate events, injector performance codes, and sensor failures.

9. Look for Cat Certified Used. A Cat Certified Used machine has passed a comprehensive 140-point inspection, including engine, hydraulics, and undercarriage checks, and comes with warranty coverage. These machines command a premium but offer the lowest risk.

10. Beware of repainted machines. Fresh paint can hide cracks, weld repairs, and hydraulic leaks. Look for paint overspray on hydraulic hoses, wiring, and decals — telltale signs of a cosmetic refresh intended to hide problems. A legitimate seller will be transparent about any repainting and its purpose.