Part of the Case Repair Manuals.
Need to rebuild the drive motor on your crawler excavator? This 927-page Case 688 service manual pdf (OEM #DON 8-88991) breaks down every component from the final drive transmission to the turntable bearing. You get complete hydraulic schematics detailing the swing control valve circuits and full electrical wiring diagrams for tracking down parasitic draws. Open up the engine section to find detailed troubleshooting charts and page after page of step-by-step teardown procedures. Verify the No. 1 compression ring end gap sits between 0.25 and 0.55 mm, then torque the boom cylinder piston to exactly 400 Nm. Guessing clearances leads to blown engines and wasted weekends. Grab this bookmarked file, pull it up on your shop tablet, and start turning wrenches.
What's Inside This Case 688 Manual
| System | Pages | Key Topics |
|---|---|---|
| General | 6-35 | Sectional Index, Safety, General Information and Torque Specifications (Standard Torque Data for Nuts and Bolts, Torque Data for Hydraulic Fittings) |
| Engine | 36-263 | Cylinder Head, Valve Train, Cylinder Block, Pistons, Crankshaft, Camshaft |
| Fuel System | 264-327 | Fuel Filters, Fuel Injectors, Fuel Injection Pump, Fuel Shutoff Solenoid, Primer Pump, Injection Pump Timing |
| Electrical | 328-432 | Alternator, Battery, Starter Motor, Electrical Schematics, Troubleshooting, Printed Circuit Board |
| Track | 433-458 | Front Idler, Track Roller, Sprocket, Spring |
| Power Train | 459-530 | Drive Motor, Final Drive Transmission, Swing Motor, Swing Reduction Gears, Brakes |
| Hydraulics | 531-869 | Hydraulic Troubleshooting, High Pressure Pump, Attachment Valve Bank, Drive Control Valve, Swing Control Valve, Hydraulic Oil Tank |
| Mounted Equipment | 870-927 | Upperstructure, Turntable Bearing, Boom, Dipper, Bucket, Cab |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Standard Torque Data for Nuts and Bolts (10 mm, Grade 8.8) | 44 Nm / 32 lb-ft | p. 11 |
| Boom Cylinder Piston to Piston Rod Torque | 400 Nm / 295 lb ft | p. 838 |
| Piston Rings No. 1 Compression End Gap in 102.02 ID Cylinder | 0.25 to 0.55 mm | p. 117 |
| Piston Rings No. 1 Compression Side Clearance | 0.075 to 0.120 mm | p. 117 |
| Radiator Cap Pressure | 1.03 Bar / 15 psi | p. 55 |
| Lower Radiator Mounting Bolts Torque | 44 Nm / 32.5 lb ft | p. 55 |
| Pilot Circuit (servo-asistance) Operating Pressure | 33 to 36 Bar / 478 to 522 psi | p. 535 |
| Boom Flow Setting (Flowmeter) | 148 to 155 l/min / 39.1 to 40.9 US gal/min | p. 544 |
| Thermostat Fully Open Temperature | 94°C / 201°F | p. 22 |
| Engine Oil Capacity (with filter change) | 10.5 litres | p. 17 |
| Fuel Tank Capacity | 247 litres | p. 17 |
| Total Hydraulic System Capacity | 155 litres | p. 17 |
