Part of the Case Repair Manuals.
Swing bearing loose, travel motor dragging, or a pilot circuit that will not hold: the 771-page Case CX50B service manual PDF, shop manual 6-77470NA, answers those jobs on the hydraulic excavator itself. Wiring diagrams trace circuits from the key switch through the solenoids, and hydraulic schematics show pump-to-valve-to-cylinder routing across the machine. Troubleshooting runs a substantial block of the book, splitting hydraulic, electrical, and engine faults into charts you follow from symptom to the test that proves it. Set piston pump P1 and P2 working pressure at 23.0 MPa (3340 psi), check the 2-speed shift signal at 3.5 MPa (507 psi), and fill the 3TNV82A with 3.6 L. Text-searchable, it prints clean, so the pages you need can live on the bench and take some grease.
What's Inside This Case CX50B Manual
| System | Pages | Key Topics |
|---|---|---|
| Standard Specifications and Maintenance | 4-105 | Specifications (Components Name, Machine Dimensions, Performance) |
| Hydraulic, Electrical, and Component Systems | 106-259 | Hydraulic System Summary, Electrical System, Hydraulic Components, Electrical Equipment, Circuit Operation |
| General Disassembly and Assembly | 260-495 | General Disassembly, Attachments, Upper Slewing Structure, Travel System, Disassembly Procedures |
| Troubleshooting | 496-543 | Hydraulic System Troubleshooting, Electrical System Troubleshooting, Engine Troubleshooting, Diagnostic Procedures |
| Engine | 544-767 | Engine Nomenclature, Periodic Maintenance, Inspection and Adjustment, Disassembly and Reassembly, Lubrication System, Cooling System, Fuel Injection Pump, Turbocharger |
| Electrical and Hydraulic Schematics | 768-771 | Electrical Schematic, Hydraulic Schematic, Piping Diagrams, Component Identification |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Working pressure (Piston pump P1 + P2) | 23.0 MPa (3340 psi) | p. 212 |
| Working pressure (Gear pump P3) | 20.0 MPa (2900 psi) | p. 174 |
| Rated operating pressure | 23.0 MPa (3340 psi) | p. 212 |
| 2-Speed shifting pressure | 3.5 MPa (507 psi) | p. 212 |
| Engine Oil Capacity (3TNV82A Total) | 3.6 L | p. 569 |
| Coolant Water Capacity (3TNV82A) | 1.8 L | p. 569 |
| Main Relief Valve Setting (P1, P2) | 23.0 +0.5 MPa (3340 +72 psi) | p. 89 |
| Travel Motor Mounting Bolt Torque | 181 Nm (133 lb ft) | p. 455 |
| Sprocket Mounting Bolt Torque | 181 Nm (133 lb ft) | p. 454 |
| Cylinder Head Bolt Torque (TNV82A First Step) | 30.0-34.0 Nm (3.1-3.5 kgf-m) | p. 642 |
| Cylinder Head Bolt Torque (TNV82A Second Step) | 61.7-65.7 Nm (6.3-6.7 kgf-m) | p. 642 |
| Connecting Rod Bolt Torque (3TNV82A) | 37.2-41.2 Nm (3.8-4.2 kgf-m) | p. 659 |
Case CX50B Common Problems This Manual Covers
Case CX50B creeps or barely moves in both low and high travel speed ranges
Check travel circuit pressure before pulling the final drive. Working pressure at the piston pumps should hit 23.0 MPa (3340 psi) per the spec on page 212, and 2-speed shifting pressure should read 3.5 MPa (507 psi). Low pressure on one side points to a travel motor or pump, not the undercarriage.
Manual Section: Hydraulic System Troubleshooting p. 212Tracks sag, jump the sprocket, or throw a chain on side hills
Measure track sag across the top rollers and inspect sprocket teeth for hooked or pointed wear. Replace worn sprockets, idlers, and bottom rollers as a set so the new chain does not wear in a step pattern. Torque sprocket mounting bolts to 181 Nm (133 lb ft), the value listed on page 454.
Manual Section: Travel System p. 454Boom and arm cylinders drift down under load, bucket lifts slow and weak
Warm the oil, then test main relief pressure at a test port. The setting on page 89 is 23.0 +0.5 MPa (3340 +72 psi). If relief holds but one function is weak, the leak is past a cylinder piston seal or spool. Trace the circuit on the hydraulic schematic.
Manual Section: Hydraulic System Troubleshooting p. 89Engine cranks slowly or will not start in cold weather
Load test the battery and clean both cable ends down to bare metal before condemning the starter. Verify alternator output reaches 40 A as listed on page 744 with the engine at high idle. Check engine oil level and grade against the 3.6 L total capacity on page 569, since heavy oil drags cranking speed down.
Manual Section: Electrical System Troubleshooting p. 745Black or white exhaust smoke with low output power under digging load
Pop test the injection nozzles first. Opening pressure should fall between 19.6 and 20.6 MPa (200 to 210 kgf/cm2) per page 610. Then set valve clearance cold to 0.15 to 0.25 mm on intake as shown on page 609. Replace the air filter before chasing fuel, since a plugged element alone will smoke black.
Manual Section: Engine Troubleshooting p. 610Swing hesitates, groans, or will not hold position on a slope
Inspect the swing bearing bolts and check bearing play with a dial indicator at the boom foot. Verify pilot circuit supply from the gear pump, rated at 20.0 MPa (2900 psi) on page 174, since weak pilot pressure will not stroke the swing spool fully. Confirm the swing motor brake releases at 0.89 MPa (129 psi).
Manual Section: Hydraulic System Troubleshooting p. 174Frequently Asked Questions
What are the torque specs for the sprocket mounting capscrews on a Case CX50B excavator?
The tightening torque for the sprocket mounting capscrew (M14) is 181 Nm (133 lb ft). p. 144
What are the service limits for the sprocket teeth width and outside diameter?
The service limit for the sprocket teeth width is 27 mm (1.06 in), and the service limit for the sprocket outside diameter is 427 mm (16.8 in). p. 144
What is the standard tightening torque for M10 bolts on the CX50B?
The standard tightening torque for an M10 bolt (10.9T) is 83.4 Nm (61.5 lb ft) for non-lubricated threads, or 70.6 Nm (52.1 lb ft) for lubricated threads. p. 60
What is the procedure for bleeding air from the fuel system?
To bleed the fuel system, loosen the air bleeding bolt on the water separator by turning it 2-3 times counter-clockwise. When the fuel coming out is clear and free of bubbles, tighten the air bleeding bolt. p. 131
What is the standard valve clearance for the 3TNV82A engine in a Case CX50B excavator?
The standard valve clearance for the 3TNV82A engine is 0.15 to 0.25 mm for both intake and exhaust valves. p. 144
Will this Case CX50B Service Manual download right away?
You get a 771-page searchable PDF that downloads instantly after checkout. Open it on your laptop, tablet, or phone, and bring it right to the shop floor.
Can I print just the pages I need from this Case CX50B manual?
You can. The PDF is unlocked and carries no copy protection, so print the sections you want and keep the file as your backup.
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