Part of the Yanmar Repair Manuals.
Need the Yanmar ViO38U service manual PDF with full factory specs? This 487-page OEM reference puts factory-level detail on every system of the ViO38U compact excavator: engine internals, fuel injection, hydraulic circuits, and electrical troubleshooting. Inside, you get complete wiring diagrams with monitor and alarm circuit logic, a full hydraulic circuit schematic tracing flow through the control valve, pilot valve, swing motor, and travel motor, plus a dedicated troubleshooting section with a compression pressure test guide and quick-reference fault tables. Separate torque tables break out machine fasteners, engine hardware, and hydraulic fittings. Check the hydraulic return filter bypass valve setting at 0.15 MPa and verify the air cleaner's 0.9 m² filtration area before putting anything back together. Your machine isn't making money sitting in the yard. Download, search by keyword, and get to work.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| General Cautions for Maintenance Work | 8-9 | Correct Work, Safety Precautions, Preparations, Cautions for Disassembly and Reassembly, Cautions for Removal and Installation of Hydraulic Equipment |
| Technical Data | 18-31 | Specifications, Outline Drawing and Working Area, Weight List of Main Parts, Lifting Capacity List |
| Service Standards | 32-55 | Machine Performance, Engine, Undercarriage (Rubber Crawler Specifications, Steel Crawler Specifications, Common Specifications of Steel & Rubber Crawlers), Controls |
| Safety (Engine) | 58-69 | Safety Precautions for Engine Disassembly, Assembly, And Service Operations |
| Engine | 70-115 | Engine Assembly, Disassembly, Pistons, Crankshaft, Cylinder Head, Valve Train, Component Inspection and Clearances |
| Fuel System | 116-147 | Fuel Injection Pump, Injection Nozzle, Fuel Filter, Bleeding Procedures, Injection Timing Adjustment |
| Cooling System | 148-155 | Radiator, Water Pump, Thermostat, Coolant Capacity, Cooling Fan, Belt Tension |
| Lubrication System | 156-163 | Oil Pump, Oil Pressure Specifications, Oil Filter, Lubrication Circuit, Oil Capacity 3.5 L |
| Starter Motor | 164-178 | Starter Motor Disassembly, Assembly, Brush Wear Limits, Commutator Inspection, No-Load Test Specifications |
| Alternator and Wiring | 179-199 | Alternator Output, Regulator, Rotor and Stator Tests, Wiring Harness, Engine Electrical Troubleshooting |
| Electric System | 200-211 | Electrical Equipment Layout, Monitor and Alarm Systems, Wiring Diagram, Engine start/stop Circuit, Battery Charging |
| Hydraulic System | 212-308 | Hydraulic Pump, Control Valve, Pilot Valve, Swing Motor, Travel Motor, Pressure Adjustment |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Return filter type | Y2502 | p. 23 |
| Return filter filtration area | 4600 cm² | p. 23 |
| Oil/water separator type | Mesh filter | p. 25 |
| Air cleaner type | Cyclone type | p. 25 |
| Air cleaner filtration area | 0.9 m² | p. 25 |
| Allowable clearance for front attachment pins and bushings | 1 mm | p. 47 |
| Idler & shaft pin wear limit (Steel Crawler) | 20 mm | p. 45 |
| Headlight power | 12-55 V-W | p. 26 |
| Boom light power | 12-55 V-W | p. 26 |
| Thermostat opening temperature | 70 to 73 °C | p. 25 |
| Thermostat full-open temperature | 80 to 84 °C | p. 25 |
| Engine Model | 3TNV88-BQBVA | p. 24 |
