Part of the Yanmar Repair Manuals.
Somewhere around hour 500, the hydraulic tank line filter on a Yanmar C50R-3C comes due, and the job stalls the moment you need the one number nobody remembers: the torque on the fitting, the pressure spec, the interval you actually missed. This 573 page factory service manual (publication 0BKC3-G50302) ends that stall, covering the C50R-3C crawler carrier from the 4JJ1X diesel down to the track rollers.
Inside are servicing standards with wear limits and a full tightening torque table, hydraulic system teardown for the pump, travel motor, swing motor, and control valve, electrical and hydraulic circuit diagrams, troubleshooting charts including HST, and a complete engine workshop manual.
The PDF carries 168 bookmarks, so jumping from a symptom in the troubleshooting chapter to the matching spec in the servicing standards takes seconds, not a flip through five hundred loose photocopies.
What's Inside This Yanmar C50R-3C Manual
| System | Pages | Key Topics |
|---|---|---|
| General Cautions for Maintenance Work | 7-20 | Correct Work, Safety Precautions, Preparations, Cautions for Disassembly and Reassembly, Cautions for Removal and Installation of Hydraulic Equipment |
| Technical Data | 21-36 | Outside Drawing, Hydraulic Circuit Diagram, E Lectrical Circuit Diagram, Main Parts Mass Chart |
| Servicing Standards | 37-52 | Servicing Standards for Parts of Undercarriage, Control Equipment, Hydraulic Equipment, Working Equipment, Tightening Torque Table |
| Engine Servicing Procedure | 53-54 | - |
| Structure and Operating Principles | 55-66 | Components and Names, Power Transmission Mechanism, Electrical Equipment of the Machine, Explanation of Starting and Stopping Engine Circuit |
| Hydraulic System | 67-234 | Outline, Hydraulic Pump, Gear Pump, Travel Motor, Swing Motor, Control Valve, Remote Control Valve, Swivel Selector |
| Service Procedures for Individual Components | 235-301 | Engine Related Components, Electrical Equipments, Undercarriage, Control System, Hydraulic System, Riggings, Swing Wagon |
| Periodic Inspection and Servicing | 302-305 | List of Periodic Inspection and Servicing |
| Fuel, Lube Oil and Grease Recommended | 306-309 | Fuel, Lube Oil and Grease Recommended |
| Troubleshooting | 310-323 | HST Troubleshooting |
| Option | 324-331 | Air Conditioner |
| Engine Workshop Manual (Isuzu 4JJ1X) | 332-573 | General Information, Engine |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| General tightening points (Coarse) M6 × 1.0 | 7.2 ±0.4 ft·lbf (9.8 ±0.5 N·m) | p. 46 |
| General tightening points (Fine) M8 × 1.0 | 18.1 ±0.9 ft·lbf (24.5 ±1.2 N·m) | p. 46 |
| Hydraulic oil tank line filter replacement interval | Every 500 hrs. (After first 250 hrs.) | p. 39 |
| Hydraulic oil tank return filter replacement interval | Every 1000 hrs. (After first 50 hrs.) | p. 39 |
| Tightening torque for metal fitting on hydraulic piping | Specified tightening torque (general guidance, no single value) | p. 16 |
| Tightening torque for HST pump bolts (M10x25-P1.5) | 36.9 ft·lbf (50 N·m) | p. 253 |
| Track roller & shaft (A) allowable limit | ø10.24 (260) in. (mm) | p. 42 |
| Sprocket (A) allowable limit | 1.46 (37) in. (mm) | p. 43 |
| Oil seal (Travel Motor) inspection standard | Replace | p. 155 |
| Air cleaner replacement interval | Every 1000 hrs. (After first 50 hrs.) | p. 39 |
| Pre-fuel filter replacement interval | Every 500 hrs. | p. 39 |
| Main fuel filter replacement interval | Every 500 hrs. | p. 39 |
Yanmar C50R-3C Common Problems This Manual Covers
One track weak or not driving
When one side drags or quits pulling, the travel motor is the usual suspect. Chapter 6 covers travel motor structure, disassembly, and inspection alongside the hydraulic pump and control valve, so you can trace the fault before ordering parts.
Manual Section: Chapter 6 Hydraulic System p. 67Slow or weak hydraulic functions
Sluggish dump or swing usually points to low oil, clogged filters, air in the system, or pump wear. The troubleshooting charts, including a dedicated HST troubleshooting section, walk from symptom to cause, and the manual gives measurable standards like a dump speed of 6.2 ±0.6 seconds extended.
Manual Section: Chapter 10 Troubleshooting p. 310Engine cranks but will not start
Hard starting on a diesel comes down to fuel delivery, air ingress, or the starting circuit. Chapter 5 explains the starting and stopping engine circuit and the machine's electrical equipment so you can test the circuit instead of swapping parts.
Manual Section: Chapter 5 Structure and Operating Principles p. 55Overheating during work
A machine that runs hot under load will take out gaskets and hoses if you keep working it. The Workshop Manual section covers the engine in depth, and the manual lists a 14.8 quart radiator capacity so you refill correctly after a cooling repair.
Manual Section: Workshop Manual p. 332Hydraulic leaks at hoses and fittings
A weeping fitting loses pressure and lets contamination in, which then eats pumps and motors. Chapter 7 gives removal and installation procedures for the hydraulic system components, with exact torques such as 36.9 ft·lbf for the HST pump bolts.
Manual Section: Chapter 7 Service Procedures for Individual Components p. 235Worn rollers, idler, or sprocket
Track component wear creeps up until tension and tracking go bad. Chapter 3 lists allowable wear limits, including a 1.46 in sprocket limit, plus torques like 217 to 238.7 ft·lbf for the nuts installing the track rollers.
Manual Section: Chapter 3 Servicing Standards p. 37No service history on a used machine
Buying secondhand with no records means guessing what was done. Chapter 8 lays out the full list of periodic inspection and servicing so you can baseline the machine, with filter and fluid intervals such as the air cleaner after the first 50 hours and every 1000 hours thereafter (page 39).
Manual Section: Chapter 8 Periodic Inspection and Servicing p. 302Frequently Asked Questions
Which machine and engine does this manual cover?
It covers the Yanmar C50R-3C crawler carrier, Yanmar publication 0BKC3-G50302, with the 4JJ1X diesel engine. Chapters cover the hydraulic, electrical, control, and track systems of the machine, and a bound-in Workshop Manual section covers the engine itself.
Does it include torque specs and wear limits?
Yes. The Chapter 3 Servicing Standards section has a general tightening torque table plus special torques (for example, 217 to 238.7 ft·lbf for the track roller nuts) and allowable limits for track components, control equipment, hydraulic equipment, and working equipment. p. 37
Does it cover service on the 4JJ1X engine?
Yes. The Workshop Manual section at the back is dedicated to the engine, covering general information and engine service, and Chapter 7 handles removal and installation of engine related components on the machine. p. 332
Will it help me troubleshoot hydraulic or drive problems?
The Chapter 10 Troubleshooting section provides symptom-based charts, including a dedicated HST troubleshooting section for the drive system. Chapter 6 backs it up with structure and service detail for the hydraulic pump, travel motor, swing motor, and control valve. p. 310
How quickly can I access this manual after buying?
This is a 573-page searchable PDF ready for immediate download. Works on any device, so pull it up on your phone while you're under the hood. No shipping, no waiting.
Am I able to print pages from this manual?
Absolutely. No DRM or copy protection. Print the whole manual or just the pages you need. Any home or office printer works.
Can I find wiring schematics in this Yanmar C50R-3C manual?
Yes. You'll find full electrical schematics with wire routing diagrams, connector identification, and circuit descriptions.
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