Part of the Yanmar Repair Manuals.
When a ViO20 starts losing revs the moment the boom cylinder loads up, the crew stands still while you guess between fuel, hydraulics, and adjustment. This Yanmar ViO20 service manual takes the guessing out: 436 pages of factory procedures for the 3TNE74-ENBV diesel, the hydraulic system, and the undercarriage of this mini excavator.
The Service Standards section pins down wear limits for rubber and steel crawlers, track rollers, and hydraulic cylinders, plus a full tightening torque list for the machine and engine. The Engine section walks through compression measurement, valve clearance adjustment, fuel injection timing, and cooling system checks, with the specifications to judge what you measure.
It is an English-language PDF (34.46 MB) delivered as an instant download, so you can print the pages you need at the bench and get the machine back on the dirt instead of waiting on a dealer appointment.
Complete the set for your ViO20
- Parts Catalog: Yanmar VIO20 Parts Manual (incl. Wiring)
- Operator Manual: Yanmar ViO20 Excavator Operator Manual
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| General Cautions for Maintenance Work | 7-18 | Hydraulic Equipment Handling, Hydraulic Piping, Seal Handling, Hydraulic Hose Installation, Hydraulic Hose Specifications |
| Technical Data | 19-31 | Specifications, Outline Drawing, Working Area, Weight List, Lifting Capacity |
| Service Standards | 32-51 | Machine Performance, Engine, Undercarriage, Rubber Crawler, Steel Crawler, Controls, Hydraulic Cylinders, Tightening Torque |
| Engine | 52-94 | Compression Pressure, Valve Clearance, V-Belt, Fuel Injection Valve, Fuel Injection Timing, Cylinder Head, Piston, Crankshaft, Starter Motor, Alternator |
| Hydraulic System | 95-132 | Control Valve Operation, Hydraulic Circuit Schematic, Circuit Operation, Boom, Arm, Bucket, Swing, Travel, Pressure Adjustment, Relief Valves |
| Hydraulic Equipment | 133-311 | Hydraulic Pump, Control Valve, Pilot Valve, Swing Motor, Travel Motor, Pilot Check Valve |
| Adjustment and Repair | 312-388 | Electrical Equipment, Wiring Diagram, Engine Removal, Starter Motor, Undercarriage, Idler, Track Roller, Control Train, Swing Bearing, Hydraulic Cylinders, Swivel Joint, Piping |
| Periodic Inspection and Servicing | 389-391 | Periodic Inspection Schedule, Servicing Intervals |
| Fuel, Lube Oil and Grease | 392-393 | Recommended Fuel, Lubricants, Grease |
| Troubleshooting | 394-433 | Non-Breakdown Phenomena, Machine and Engine Faults, Electrical Equipment on Panel |
| Reference Data | 434-436 | Attachment Specifications |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Track roller tightening nut torque | 57.9 to 72.3 ft·lbf (78.4 to 98.0 N·m) | p. 48 |
| Pipe joint bolt (M12) tightening torque | 18.1 to 25.3 ft·lbf (24.5 to 34.3 N·m) | p. 51 |
| Swing motor to Turning frame tightening torque | 57.9 to 72.3 ft·lbf (78.4 to 98.0 N·m) | p. 49 |
| Travel reduction gear oil type | SAE 90 (GL-4) | p. 393 |
| Travel reduction gear oil capacity | 0.53 Qts. (0.5 L) | p. 393 |
| Hydraulic hose working pressure (SAE J517, 100R1, 02 dia.) | 2489 (17.2) PSI (MPa) | p. 14 |
| Hydraulic pipe joint bolt (M12) tightening torque | 18.1 to 25.3 ft·lbf (24.5 to 34.3 N·m) | p. 51 |
| Fuel-water separator element type | Mesh filter | p. 25 |
| LO filter filtration area | 124.1 (800) sq.in. (sq.cm) | p. 25 |
| LO filter valve opening pressure | 11.4 to 17.1 (0.08 to 0.12) PSI (MPa) | p. 25 |
| Air cleaner filtration area | 9.7 (0.9) sq.ft. (sq.m) | p. 25 |
| Rubber crawler lug height wear limit | 0.39 (10) in. (mm) | p. 41 |
