Part of the Case Repair Manuals.
Your 680 has the boom drifting down under load and the loader feels soft, and the fix starts in the Case 680B, 680C, W7E, 680 CK service manual PDF, 834 pages of factory repair data published under OEM number 9-71984 for these loader backhoe models. Hydraulic testing walks you through pump, control valve, and cylinder work before you condemn a part, while wiring coverage maps the Series B and Series C electrical systems circuit by circuit. Exploded views and rebuild procedures take up big blocks of the book, from the A267 diesel bottom end to the Model 36 backhoe. Set boom-down relief pressure to 1250 psi (1100 to 1350 at 10 gpm), pull cylinder head bolts to 145 to 155 ft. lbs. Backhoe hydraulic troubleshooting eats whole afternoons when you are guessing at pressures. Text is searchable and bookmarked by system, and it prints clean, so the pages can live on your bench and take some grease.
What's Inside This Case 680B, 680C, W7E, 680 CK Manual
| System | Pages | Key Topics |
|---|---|---|
| General | 3-22 | Specifications for Case A267 Diesel Engine, Series B Prior to SN 9103967, Lubrication, Maintenance, And Torque Charts, Series B, Maintenance and Lubrication, Series C |
| Engine | 23-234 | Prior to SN 9103967 (Throttle Controls and Linkage, Stall Checks, Air Intake and Exhaust System) |
| Fuel System | 235-328 | Prior to SN 9103967 (Fuel Injectors, Case Powrcel Fuel Injection Pump), SN 9103967 Thru 9111008 (Electric Fuel Pump, Fuel System and Filters, Fuel Injection Pump, Fuel Injectors) |
| Hydraulics | 329-360 | Hydraulic Testing, Equipment Pump, Control Valves, Hydraulic Cylinders |
| Steering | 361-498 | Hydraulic Cylinders, Hydrostatic Steering System, Steering System |
| Power Train | 499-616 | 4-Speed Synchromesh Transmission Series C, Differential and Planetaries, Series C, 4-Speed Mechanical Transmission and Differential Brakes, Supplement to Section S |
| Brakes | 617-652 | Series C, Hydraulic Brake System, Series B |
| Electrical System | 653-740 | Electrical |
| Mounted Equipment | 741-834 | Loader, Loader Supplement, Series C, Model 36 Backhoe |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Camshaft Nut | 95 to 105 Ft. Lbs. | p. 9 |
| Connecting Rod Bolts | 95 to 105 Ft. Lbs. | p. 9 |
| Pump mounting bolts torque | 200 ft. lbs. | p. 332 |
| Special fitting torque | 20 ft. lbs. | p. 353 |
| Boom (Down) Relief Valve Pressure | 1250 psi, range 1100-1350 @10 gpm | p. 408 |
| Boom ("B" Port) Relief Valve Pressure | 2750 psi, range 2600-2900 @10 gpm | p. 408 |
| Stud nut torque | 200 foot pounds (2400 inch pounds) | p. 366 |
| Tilt spool secondary relief valve setting | 2500 P.S.I., range 2400-2600 P.S.I. @ 10 G.P.M. | p. 377 |
| Clam spool secondary relief valve setting | 2500 P.S.I., range 2100-2300 P.S.I. @ 10 G.P.M. | p. 377 |
| A267 Engine Full Load Rated Engine Speed | 2000 RPM | p. 4 |
| A267 Engine No Load Governed Engine Speed | 2150 RPM | p. 4 |
| A267 Engine Idle Speed | 750 RPM | p. 4 |
