If you need to rebuild your industrial diesel engine, this 136-page Yanmar TNV Series Service Manual PDF (OEM #M9961-02E070) breaks down the complete cylinder block, gear train, and fuel injection pump assemblies. Inside, you get full electrical wiring diagrams for the alternator and starter, along with step-by-step diagnostic charts to track down compression issues. Open the maintenance section to find precise service schedules and exploded views of the trochoid lubrication pump. Set the fuel injection nozzle pressure between 11.8 and 12.8 MPa, and make sure to swap in a fresh 119740-55650 fuel filter element every 500 hours.
What's Inside This Yanmar 2TNV70, 3TNV70, 3TNV76 Manual
| System | Pages | Key Topics |
|---|---|---|
| Preface | 3 | Service Procedures for Tnv Series Engines, Standard Engine Specifications, Components, Work Equipment Service Manual, Engine Quality Improvement, Specification Changes |
| Safety Labels | 4 | Basic Safety Rules and Precautions, Safety Precautions, Inspection and Maintenance Procedures, Safety Consideration, Safety Marks and Their Meanings, Danger, Warning, Caution |
| Safety Precautions | 5-8 | Service Area, Work Wear, Tools, Genuine Parts and Materials, Fastener Torque, Electrical, Waste Management, Further Precautions |
| Precautions for Service Work | 9-11 | Precautions for Safety, Preparation for Service Work, Preparation Before Disassembly, Precautions in Disassembly, Precautions for Inspection, Measurement, Adjustment and Check |
| General | 16-29 | Engine Nomenclature, Specifications, Fuel Oil, Lubricating Oil and Cooling Water, Engine External Views, Structural Description |
| Inspection and Adjustment | 30-56 | Periodic Maintenance Schedule |
| Troubleshooting | 57-62 | Preparation Before Troubleshooting, Quick Reference Table for Troubleshooting, Troubleshooting by Measuring Compression Pressure |
| Disassembly, Inspection and Reassembly of Engines | 63-102 | Complete Disassembly and Reassembly (Introduction, Special Service Tools, Precautions Before and During Reassembly, Operation), Cylinder Head: Disassembly |
| Lubrication System | 103-105 | Lubrication System Diagram, Trochoid Pump Components, Disassembly, Servicing Points, Parts Inspection and Measurement (Trochoid Pump Inspection and Measurement) |
| Cooling System | 106-107 | Cooling Water System, Cooling Water Pump Components, Disassembly (Reverse the Below Procedure for Reassembly), Servicing Points |
| Fuel Injection Pump / Governor | 108-111 | Introduction |
| Starting Motor Specifications and Characteristics | 112-114 | Specifications and Characteristics, Structure of a Starting Motor and the Wiring Diagram, Performance |
| Alternator | 115-122 | 20A Alternator (Specifications, Structure, Wiring Diagram, Standard Output Characteristics, Inspection) |
| Electric Wiring | 123-127 | Electric Wiring Diagram (Alternator, Starter) |
| Service Standards | 128-133 | Engine Tuning, Engine Body, Lubricating Oil System (Trochoid Pump) |
| Tightening Torque for Bolts and Nuts | 134-135 | Tightening Torques for Main Bolts and Nuts, Tightening Torques for Standard Bolts and Nuts |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| All Models | ||
| Fuel injection nozzle pressure (Standard) | 11.8~12.8 MPa (120~130 kgf/cm²) | p. 48 |
| Fuel filter element replacement interval | Every 500 hours or 6 months | p. 43 |
| Fuel filter element Part No. | 119740-55650 | p. 43 |
| Air cleaner element cleaning/replacement interval | Every 250 hours or 3 months | p. 41 |
| Starter motor Manufacturer's model | P1.1 | p. 112 |
| Starter motor Yanmar code | 119717-77010 | p. 112 |
| Cooling water pump bearing inspection | Check for abnormal noise, sticking or play and water leakage. Replace whole pump assy if necessary. | p. 107 |
| Thermostat valve opening temperature | 69.5~72.5 °C | p. 55 |
| Thermostat full open lift (at 85°C) | 8 mm or more | p. 55 |
| 2TNV70 | ||
| Cooling water capacity (engine only) | 0.6 L | p. 128 |
| 2TNV70 Displacement | 0.570 L | p. 17 |
| 3TNV70 | ||
| 3TNV70 Displacement | 0.854 L | p. 18 |
Yanmar 2TNV70, 3TNV70, 3TNV76 Common Problems This Manual Covers
Yanmar 3TNV70 turns over slowly in cold weather and exhibits a hard starting or no-start condition. p. 112
Test the starter motor electrical draw. Verify the no-load terminal voltage and current are 11.5V/90A or less as specified on page 112. Inspect the overrunning clutch system for wear. Measure the loaded torque to ensure it reaches 8.24 Nm. Replace the starter assembly if values fall out of range.
Manual Section: 8. the Specifications of a Starting Motor and the CharacteristicsDiesel engine runs rough under load, surges erratically at idle, and shuts off unexpectedly. p. 48
Check the fuel injection nozzle pressure using a pop tester. Adjust the pressure to the standard 11.8~12.8 MPa range detailed on page 48. Inspect the fuel filter element and replace it if it exceeds the 500-hour service interval. Bleed all air from the fuel lines before restarting.
Manual Section: 2. Inspection and AdjustmentExhaust emits excessive black smoke and engine shows inability to reach rated speed under load. p. 128
Measure the intake and exhaust valve head gap with a feeler gauge. Adjust the clearance to 0.15~0.25 mm following the service standards on page 128. Inspect the air cleaner element for severe restriction. Replace the filter element if the equipment has surpassed the 250-hour maintenance interval.
Manual Section: 11. Service StandardsCoolant temperature runs high during operation accompanied by an unexplained fluid level drop and overheating. p. 55
Drain the cooling system and remove the thermostat. Suspend the unit in heated water and verify the valve opening temperature is 69.5~72.5 deg C as outlined on page 55. Check the cooling water pump bearing for abnormal noise or play. Replace the entire pump assembly if leakage is present.
Manual Section: 2. Inspection and AdjustmentFrequently Asked Questions
What is the torque specification for the cylinder head bolts on a YANMAR TNV Series engine?
The cylinder head bolts should be tightened in two steps. The first step requires a torque of 26.0~30.0 Nm (2.7~3.1 kgf·m), and the second step requires 53.9~57.9 Nm (5.5~5.9 kgf·m). This procedure is detailed in section 4.2.4 Servicing points, Point 8.
How do I bleed the fuel system on a YANMAR TNV engine?
To bleed the fuel system, first check the fuel oil level and refuel if insufficient. Then, open the fuel cocks of the water separator and fuel filter, and loosen the air bleeding bolt on the water separator by 2-3 turns. Once fuel flows out clear without bubbles, tighten the bolt and feed fuel using the priming pump or electro-magnetic fuel feed pump for 10-15 seconds.
What are the standard valve clearance specifications for a YANMAR TNV Series engine?
The standard valve clearance should be between 0.15 mm and 0.25 mm. This adjustment is necessary to maintain proper contact of the valves and seats and should be performed while the engine is cold.
What is the effective lubricating oil capacity for the oil pan of a 2TNV70 engine?
The effective lubricating oil capacity for the oil pan of a 2TNV70 engine (VM class) is 0.7 liters. The total volume is 1.7 liters. This capacity may vary depending on the machine unit the engine is installed on.
How quickly can I access this manual after buying?
A 136-page Service Manual in searchable PDF format, available the moment you complete checkout. View on computer, tablet, or phone, with no shipping wait.
Am I able to print pages from this manual?
The PDF is DRM-free. Print whatever sections you need to take out to the shop. Standard letter or A4 paper works.
Are there wiring harness diagrams in this Yanmar TNV Series manual?
Yes, full electrical schematics are included with wire colors, connector locations, and circuit descriptions.
Document Quality
This is a scanned PDF document with an OCR text layer, allowing you to search and copy the full text content. The text is generally crisp and easy to read throughout the manual. Diagrams and illustrations are scanned raster images; their labels are readable, though some may appear slightly less sharp when zoomed in. The pages are clean, free of scan artifacts, stains, or skewed content. There are no notable blank or filler pages.
Reviews
There are no reviews yet.