A swing motor that whines under load or an LS valve that won't hold its setting can idle a crew for days; this Komatsu PC88MR-6 shop manual PDF (Komatsu WEBM007200) is the 328-page factory answer for that hydraulic excavator. Disassembly and assembly fills more than a third of the book, working through the injection pump, engine head, radiator and A/C condenser, and the swing motor with its reduction gear. Hydraulic and electrical circuit diagrams close out the manual, and the structure and function chapter explains the power train, track frame and idler cushion, main pump, and control valve before you open any of them. Set the P1 general valve (boom, arm, bucket) to 265 bar, then confirm the engine holds 2080 ± 100 rpm with the pump at maximum pressure. Calibrating secondary valves from memory burns a whole shift. Bookmarked and text-searchable, the PDF is yours after one purchase, for as long as this machine runs.
What's Inside This Manual
| System | Pages | Key Topics |
|---|
| Structure and Function | 27-132 | Power Train, Swing Machinery, Track Frame and Idler Cushion, Hydraulic Pump, Control Valve |
| Testing and Adjusting | 133-196 | Normal or Standard Technical Data, Checking the Exhaust Smoke Colour, Checking and Calibrating Pressure in the Secondary Valves, Checking and Adjusting the LS Valve |
| Disassembly and Assembly | 197-320 | Injection Pump, Engine Head, Engine Pumps, Complete Radiator and Air Conditioning Condenser, Swing Motor and Reduction Gear |
| Other | 321-328 | Hydraulic Circuit Diagram, Electrical Circuit Diagram |
Quick Reference Specifications
| Specification | Value | Page |
|---|
| Standard tightening torque for 6mm bolt (8.8 grade) | 0.96±0.1 kgm (9.5±1 Nm) | p. 12 |
| Standard tightening torque for 8mm bolt (8.8 grade) | 2.3±0.2 kgm (23±2 Nm) | p. 12 |
| Main relief valve pressure | 32 kg/cm2 | p. 53 |
| Engine speed with pump at max. pressure | 2080 ± 100 rpm | p. 136 |
| General valve P1 (boom – arm - bucket) pressure | 265 bar | p. 137 |
| Servocontrols feed valve pressure | 31.4 bar | p. 170 |
| Engine High Idling Speed | 2250 +100/-50 rpm | p. 135 |
| Engine Low Idling Speed | 1100 ± 50 rpm | p. 135 |
| Engine Oil Pressure (High Idling, SAE 30) | 3.5 – 5.5 kg/cm² | p. 135 |
| Engine Oil Pressure (Low Idling, SAE 30) | 1.8 kg/cm² | p. 135 |
| Fuel Injection Timing Advance | 5 ± 0.75 degrees | p. 135 |
| Swing Circle Grease Quantity | 5.5 l | p. 29 |
