Part of the Yanmar Repair Manuals.
Pull the valve cover on the 2TNE68-EFW and you have two numbers to get right before it runs again: 0.15 to 0.25 mm of intake valve lash on a cold engine, and a healthy cylinder should still pull 470 PSI at 250 rpm. Both figures come from this Yanmar service manual for the C12R(EP) crawler carrier, publication 131103, and guessing at either one is how a quiet diesel becomes a smoky one.
The 221 page PDF covers the whole machine around that engine: service standards and tightening torques, hydraulic cylinders, tank and piping, wiring diagrams with circuit descriptions for starting and charging, periodic servicing charts, and a troubleshooting chapter. Engine work gets its own chapter, from compression testing through cylinder head, piston, crankshaft and governor measurement.
It is bookmarked for navigation, downloads immediately after purchase, and prints cleanly, so the pages that matter can sit on the bench and get dirty.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| General Cautions for Maintenance Work | 9-22 | Correct Work, Safety Precautions, Preparations, Cautions for Disassembly and Reassembly, Cautions for Removal and Installation of Hydraulic Equipment |
| Technical Data | 23-34 | Specifications, Machine Dimensions, Hydraulic Circuit Schematic, Wiring Diagram, Weight of Components |
| Service Standards | 35-50 | Machine Performance, Engine, Undercarriage, Control Devices, Hydraulic Cylinder, Work Implement, List of Tightening Torque (Machine) |
| Engine | 51-96 | Measurement |
| Structure and Operation | 97-110 | Electrical Equipment of Machine (Parts Layout of Electrical Equipment, Monitor and Alarm Systems, Wiring Diagram, Circuit Description of Engine Start and Stop, Circuit Description of Battery Charging) |
| Hydraulic Equipment | 111-146 | Hydraulic Cylinder, Hydraulic Oil Tank, Hydraulic Piping |
| Structure and Operation | 147-198 | Electrical Equipment, Undercarriage, Control Equipment, Power Transmission, Hydraulic Equipment, Wagon |
| Periodic Inspection and Servicing | 199-202 | Lube Oil, Hydraulic System, Undercarriage, Steering Equipment, Electric Equipment, Fuel, Cooling Water, Rubber Hose |
| Fuel, Lube Oil and Grease Recommended | 203-206 | Engine Oil, Transmission Oil, Hydraulic Oil, Fuel, Engine Cooling Water, Fuel Tank, Cooling System |
| Troubleshooting | 207-219 | Machine and Engine, H.S.T., Fuel System, Cooling Water System, Cylinder Head, Piston, Starter Motor, Battery |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Engine \u00d7 Engine mount tightening torque | 44.1 to 58.8 ft\u2022lbf (4.5 to 6.0 N\u2022m) | p. 48 |
| Engine mount vibroisolating rubber Nut M12 tightening torque | 32.6 to 43.5 ft\u2022lbf (44.1 to 58.9 N\u2022m) | p. 48 |
| Hydraulic oil type | YANMAR SUPER HYDRO OIL (ISO VG46) | p. 205 |
| Hydraulic oil system prescribed amount | 4.36 Gals. (16.5 L) | p. 205 |
| Fuel filter filtration area | 66.96 sq.in. (432 sq.cm) | p. 27 |
| LO filter filtration area | 124.0 sq.in. (800 sq.cm) | p. 27 |
| Air cleaner type | Cyclone type | p. 28 |
| Air cleaner filtration area | 4.7 sq.ft. (0.44 sq.m) | p. 28 |
| Hydraulic hose installation tightening torque (valve piping) | 16.6 to 20.3 ft\u2022lbf (22.5 to 27.4 N\u2022m) | p. 142 |
| HST (High) relief set pressure | 3959 to 4002 PSI (27.4 to 27.7 MPa) | p. 25 |
| HST (Low) relief set pressure | 58 to 87 PSI (0.4 to 0.6 MPa) | p. 25 |
