Part of the Kubota Repair Manuals.
This 739-page Kubota KX057-4, U55 service manual PDF (factory number RY911-20510) covers the KX057-4 and U55-4 excavators. The hydraulic circuit diagram maps the pump, control valve, swivel motor and travel motor circuits, and the hose routing drawings show where each line runs out to the boom, arm and blade cylinders. Wiring circuits, meter panel troubleshooting and pilot valve rebuilds for control, travel, swing and blade follow, plus device performance measurement so you confirm the numbers before handing the machine over. Spin the return filter on to 68.6 to 78.4 N·m; a 1/2 hose union nut takes 58.8 to 63.7 N·m. Chapter bookmarks and a searchable text layer land you on the travel motor or refrigerant section in seconds.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| Information | 6-22 | Safety First, Safety Decals |
| General | 23-76 | Checking Bachoe Identification, Engine Identification, Handring Precautions for Electrical Parts and Wiring, Tightning Torques, New Product Feature, New Features Outline |
| Machine Body | 77-117 | Front Operating Machine, Upper Swivel, Chassis |
| Engine | 118-227 | Engine Specifications, Special Tools, Troubleshooting, Servicing Specifications |
| Hydraulic System | 228-510 | Diagram of Hydraulic Circuit, Hydraulic Device Layout, Features, Pump, Control Valve, Swivel Motor, Travel Motor, Hydraulic Cylinder |
| Electrical System | 511-661 | Electronic Device Layout, Wiring Circuit, Troubleshooting, Inspections, Meter Panel Operation Procedures |
| Cabin | 662-739 | Air Conditioning System, Wiper, Troubleshooting, Maintenance and Service Related Specifications, Torque, Precautions When Repairing the Refrigerant System |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Torque for Hydraulic Hose Fittings (Union Nuts) | 7.8 to 11.8 N·m (1/8), 24.5 to 29.2 N·m (1/4), 37.2 to 42.1 N·m (3/8), 58.8 to 63.7 N·m (1/2), 117.6 to 127.4 N·m (3/4), 181.3 to 191.1 N·m (1), 220.5 to 230.3 N·m (1-1/4) | p. 37 |
| Torque for Hydraulic Hose Fittings (Tapered Nuts) | 19.6 to 29.4 N·m (1/8), 36.6 to 44.1 N·m (1/4), 68.6 to 73.5 N·m (3/8), 83.4 to 88.3 N·m (1/2), 166.6 to 181.3 N·m (3/4) | p. 37 |
| Tightening torque for filter (return) | 68.6 to 78.4 N·m | p. 90 |
| Tightening torque for nut (2) (suction filter) | 16 to 24 N·m | p. 91 |
| Tightening torque Bolt (3) | 123.6 to 147.1 N·m, 12.6 to 15.0 kgf·m, 91.17 to 108.4 lbf·ft | p. 97 |
| Oil cooler joint screw torque | 64 to 73 N·m (6.5 to 7.5 kgf·m, 47 to 54 lbf·ft) | p. 194 |
| Tightening torque for bolt (25) (hydraulic oil tank) | 77.5 to 90.2 N·m | p. 89 |
| Tightening torque for bolts (a) (b) (c) (d) (anti vibration support) | 77.5 to 90.2 N·m | p. 93 |
| AUX2 port MAX. flow volume (Theoretical) | 37 L/min (9.87 U.S.gal/min) | p. 549 |
| AUX1 port MAX. flow volume (Theoretical) | 75 L/min (20 U.S.gal/min) | p. 549 |
| Engine Oil Capacity (Crankcase) | 9.0 L | p. 66 |
