Kubota U45-3 Mini Excavator – Parts, Specs & Serial Number Guide

The Kubota U45-3 is a powerful 4.5-ton zero-tail swing mini excavator, offering the perfect blend of mid-range digging performance and jobsite flexibility. Its zero-tail swing design allows operators to dig and rotate safely in confined areas without overhang, while its robust hydraulic system and comfortable cab make it a workhorse for contractors, utility crews, and landscapers.

Key Specifications:

Engine:

• Model: Kubota V2203-M

• Type: 4-cylinder, water-cooled, diesel engine

• Displacement: 134.1 cu in (2.197 L)

• Gross Power: 39.4 hp (29.4 kW) @ 2,200 rpm

Transmission & Travel:

• Travel Speed: Low: 1.7 mph (2.7 km/h), High: 2.9 mph (4.6 km/h)

• Drive Type: Hydraulic travel motors with planetary reduction

Hydraulic System:

• Pump Capacity: 34.1 + 34.1 + 17.1 l/min (triple pump)

• Auxiliary Hydraulic Flow: 15.6 gpm (59 L/min)

• Max Hydraulic Pressure: 3,000 psi (20.6 MPa)

• Control System: Pilot-operated joystick controls with pattern selector

Dimensions:

• Operating Weight: 10,300 lbs (4,672 kg)

• Max Digging Depth: 11 ft 9 in (3.6 m)

• Max Reach at Ground Level: 18 ft 4 in (5.6 m)

• Tail Swing Radius: Zero-tail swing

Performance:

• Bucket Breakout Force: 9,485 lbf (42.2 kN)

• Arm Digging Force: 5,470 lbf (24.3 kN)

Maintenance & Common Parts:

Routine Maintenance:

• Replace fuel, oil, and air filters every 250 hours

• Grease all pivot joints daily for optimal bushing and pin life

• Inspect and adjust track tension biweekly

• Clean radiator fins and oil cooler screen regularly

Frequently Replaced Parts:

• Hydraulic Cylinder Seal Kits

• Final Drive Motors

• Rubber Tracks & Sprockets

• Fuel, Oil, and Air Filters

• Quick Couplers & Attachments

Common Issues & Quick Fixes:

• Boom Drift or Weak Cylinder Response: Usually caused by worn seals—swap in new cylinder kits.

• Final Drive Leaks or Grinding: Replace the unit with a compatible U45-3 final drive motor.

• Engine Starting Trouble in Cold Weather: Replace worn glow plugs and fuel filters.

Pro Tips:

• Use Kubota Super UDT2 fluid to ensure full compatibility and reduce system wear.

• Check track rollers and idlers monthly—uneven wear is a sign of loose or misaligned undercarriage components.

• Store with the boom slightly elevated to reduce cylinder pressure while parked.

Serial Number Location:

• Found on a metal plate on the front right side of the operator’s cab frame and stamped on the undercarriage near the hydraulic track motor.

• Record your serial number before ordering parts from our Kubota U45-3 catalog.