Keep a Liebherr A 900 - A 942 wheeled hydraulic excavator digging with the factory service manual written for it. The pages were printed in 1982 and apply from serial number 101. These machines are purely hydraulic and electromechanical, so every fix comes down to pressures, flows, clearances and torques.
The book covers the hydraulic double pump data and regulation, the oil cooling circuit, rotary connection resealing and the air brake system. It also covers swing gear, axles, the two speed gearbox, hydrostatic steering and cylinder repair. A guessed torque on a swing ring bolt or a guessed pump regulation pressure can cost you a swing bearing or a pump.
Check the pump and swing ring data for your model before you order, so the right part arrives the first time.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| General | 1-6 | Title, Contents |
| Tables, Data and Torque | 7-50 | Conversion Factors, Metric Bolt Sizes, Tightening Torques, Ermeto Couplings, ISO Tolerances, Graphic Symbols |
| Special Tools and Welding | 51-108 | Special Tools, Welding Instructions, Mini Test System, Flow Meter, Spool Travel Measuring Tool |
| Lubrication and Inspection | 109-178 | Lubrication, Technical Data, Inspection Schedule |
| Engine | 179-220 | Deutz Engine FL 912, Liebherr Engine D 904, Sensor Controlled Low Idle Automatic, Valve Clearance |
| Swing Gear and Swing Brake | 221-268 | Swing Gear, Swing Brake, Torque Values, Swing Brake Maintenance, Pressure Settings |
| Hydraulic System | 269-564 | Hydraulic Diagrams, Hydraulic Double Pump Data and Regulation, Oil Cooling Circuit and Thermostat Valve, Pump Troubleshooting by Comparative Cycle Times |
| Air Pressure System | 565-614 | Brake Valve, Air Cylinders |
| Rotary Connection | 615-632 | Hydraulic Rotary Connection Construction, Function and Resealing |
| Electrical System | 633-688 | Wiring Diagrams, Electrical Box, Charging, Starting and Accessory Circuits |
| Heater and Air Conditioner | 689-726 | Heater, Air Conditioner, Engine Oil Cab Heater, Cab Heater Installation |
| Two Speed Gearbox | 727-740 | Two-Speed Gearbox, Install Gearbox to Undercarriage |
| Axles and Differential | 741-824 | Front and Rear Axle, Differential, Contact Patterns, Removing and Installation of Rear Axle |
| Hydrostatic Steering | 825-856 | Hydraulic Circuit, Servostat, Flow Indicator |
| Oscillating Axle Support | 857-904 | Axle Stabilizers, Checking and Bleeding of System, Valve Blocks |
| Brakes | 905-926 | Pressure Chart, Wheel Cylinders, Master Cylinder, Troubleshooting of Brake System, Parking Brake |
| Swing Ring | 927-936 | Axial Play, Backlash, Swing Ring Bolt Torques, Upper Carriage Weights |
| Special Equipment and Accessory Kits | 937-1258 | Special Equipment, Accessory Kits, Overload Warning Device, Hoist Limit, Load Check Valve, Hydraulic Hammer |
| Hydraulic Cylinders | 1259-1299 | Hydraulic Cylinder Repair |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| All Models | ||
| Swing ring axial play, new | 0.8 mm (0.031 in) | p. 897 |
| Swing ring axial play, maximum | 2.2 mm (0.086 in) | p. 897 |
| Swing ring backlash | 1.4 mm (0.055 in) | p. 897 |
| Swing ring bolt torque M20 10.9 (lubricated) | 480 Nm (355 ft-lbs) | p. 897 |
| Upper carriage weight | 6250 kg (14,000 lbs) (A 900) / 7500 kg (16,535 lbs) (A 902) / 9400 kg (20,730 lbs) (A 912) / 11,000 kg (24,250 lbs) (A 922) / 12,100 kg (27,000 lbs) (A 942) | p. 897 |
| Hydraulic double pump output | 55.2 kW / 75 HP at 2300 RPM (A 912) / 69 kW / 94 HP at 2300 RPM (A 922) | p. 475 |
| Hydraulic double pump max flow | 2x126 L/min (2x33.2 GPM) (A 912) / 2x156 L/min (2x41 GPM) (A 922) | p. 475 |
| Pump regulation begin | 217 bar (3146 PSI) (A 912) / 228 bar (3300 PSI) (A 922) | p. 475 |
| A 900, A 902, A 912 | ||
| Swing ring bolt torque M16 10.9 (lubricated) | 240 Nm (180 ft-lbs) | p. 897 |
| A 922, A 942 | ||
| Swing ring bolt torque M20 12.9 (lubricated) | 570 Nm (420 ft-lbs) | p. 897 |
| A 912, A 922 | ||
| Pump Allen bolt torque | 43 Nm (32 ft-lbs) | p. 475 |
| Cooler motor constant flow | 18 L/min (4.75 GPM) | p. 331 |
| Oil cooler check valve setting | 3 bar (43 PSI) | p. 331 |
| Hydraulic oil thermostat valve | starts to close above 40 C (105 F), fully closed at approx. 55 C (130 F) | p. 331 |
