Kubota U25 Mini Excavator – Parts, Specs & Serial Number Guide

The Kubota U25 is a compact, ultra-maneuverable 2.5-ton class mini excavator featuring a true zero-tail swing design—perfect for tight urban spaces and small-scale excavation work. Despite its size, the U25 offers strong digging force, exceptional reliability, and simplified service access, making it a favorite among contractors, landscapers, and rental fleets.

Key Specifications:

Engine:

• Model: Kubota D1105-E3B

• Type: 3-cylinder, liquid-cooled, diesel engine

• Displacement: 68.5 cu in (1.123 L)

• Gross Power: 20.9 hp (15.6 kW) @ 2,300 rpm

Transmission & Drive:

• Travel Speed: Low: 1.5 mph (2.4 km/h), High: 2.7 mph (4.3 km/h)

• Drive Motors: Hydraulic axial piston motors with planetary final drives

Hydraulic System:

• Pump Capacity: 23.8 + 14.2 + 11.3 l/min (triple pump)

• Auxiliary Hydraulic Flow: 12.3 gpm (46.6 l/min)

• Max Hydraulic Pressure: 2,623 psi (18.1 MPa)

• Control System: Pilot-controlled joysticks for boom, arm, bucket, and swing

Dimensions:

• Operating Weight: 5,625 lbs (2,552 kg)

• Max Digging Depth: 8 ft 4.8 in (2.56 m)

• Max Reach at Ground Level: 14 ft 1.2 in (4.3 m)

• Tail Swing Radius: 2 ft 7 in (zero-tail swing)

Performance:

• Bucket Breakout Force: 4,990 lbf (22.2 kN)

• Arm Digging Force: 2,994 lbf (13.3 kN)

• Ground Clearance: 12 in

Maintenance & Common Parts:

Routine Maintenance Needs:

• Engine oil & filter every 100–250 hours

• Hydraulic oil & filter inspection every 250 hours

• Track tension check monthly

• Grease swing pivot, boom, and arm bushings every 10 hours

Commonly Replaced Parts:

• U25 Hydraulic Cylinder Seal Kits

• Final Drive Motors

• Rubber Tracks & Sprockets

• Fuel, Air, and Oil Filters

• Control Levers and Foot Pedals

Common Issues & Quick Fixes:

• Hydraulic Drifting or Weak Boom: Usually indicates worn cylinder seals—install new seal kits.

• Final Drive Sticking or Leaking: Caused by worn seals or contaminated gear oil—replace with a complete U25 final drive motor.

• Rubber Track Wear or Tension Loss: Inspect regularly and replace with durable OEM-fit rubber tracks.

Pro Tips:

• Use biodegradable hydraulic fluid when working in environmentally sensitive areas.

• Keep the radiator and oil cooler screens clean to avoid overheating in tight urban zones.

• Grease all pivot points daily for extended bushing and pin life.

Serial Number Location:

• Found on the right side of the machine frame near the hydraulic track motor or stamped near the front right cab base.

• Use your serial number to match exact-fit Kubota U25 parts.