Komatsu's own document number, WEBM008601, is printed on the cover of this Komatsu PC80MR-3 shop manual PDF, the 302-page factory book written for that hydraulic excavator. Hydraulic circuit and electrical diagrams close out the book, the hydraulic sheet tracing oil from the pump group through the control valve, while the largest share of pages goes to disassembly and assembly of the injection pump, engine head, swing motor and reduction gear, and swivel joint. Before you split anything, Testing and Adjusting walks you through engine speed measurement, exhaust smoke colour, and pinning down the cause of hydraulic drift. Check the track frame idler guide against its 74 mm basic width and 78 mm limit, and fill the final drive with SAE 85W-90. Guess a figure and you pay for the second teardown. Bookmarks and a live text layer take you straight to the right procedure, and your PC80MR-3 is swinging a bucket again before the crew loses another shift.
What's Inside This Manual
| System | Pages | Key Topics |
|---|
| Structure and Function | 27-108 | Power Train, Swing Machinery, Track Frame and Idler Cushion, Control Valve |
| Testing and Adjusting | 109-174 | Normal or Standard Technical Data, Measuring the Engine Speed, Checking the Exhaust Smoke Colour, Analysis of the Causes of Hydraulic Drifts |
| Disassembly and Assembly | 175-294 | Counterweight, Injection Pump, Engine Head, Pump Group, Engine Pumps, Complete Radiator and Air Conditioning Condenser, Swing Motor and Reduction Gear, Swivel Joint |
| Other | 295-302 | Hydraulic Circuit, Electrical Diagram |
Quick Reference Specifications
| Specification | Value | Page |
|---|
| Final drive oil viscosity | SAE 85W-90 | p. 17 |
| Tightening torque for nuts of flared (1/2" - 20) | 2.6±0.5 kgm (25.5±4.9 Nm) | p. 13 |
| Tightening torque for nuts of flared (9/16" - 18) | 4±0.5 kgm (39.2±4.9 Nm) | p. 13 |
| Vertical width of idler guide (Track frame) | 74 mm (Basic dimension), 78 mm (Limit size) | p. 35 |
| Vertical width of idler guide (Idler support) | 73 mm (Basic dimension), 69 mm (Limit size) | p. 35 |
| Travel motor change displacement pressure | 32 bar | p. 46 |
| Travel motor min. pressure opening brake | 13 bar | p. 46 |
| Tightening torque of cylinder head (Boom) | 961 ± 96.1 Nm | p. 51 |
| Tightening torque of cylinder head (Boom swing) | 785 ± 78.5 Nm | p. 51 |
| General valve P1 (boom – arm - bucket) - Boom swing and travel | 256 – 275 bar | p. 113 |
| Main valve P2 (Blade - Swing) | 201 – 215 bar | p. 113 |
| Engine High Idling Speed | 2250 +100/-50 rpm | p. 111 |
