Komatsu PC78MR-6 Excavator Service Manual Workshop Guide

Manual Included: Shop Manual: 589 pages Specifications: Brand: Komatsu Model: PC78MR-6 Type: Excavator Serial Number: 1001 and up Manuals: Shop Manual Publication Number: SEBM030604 Language: English Format: PDF Description Table of Contents 01 GENERAL ………………………………………………………………………………………………….01-1 10 STRUCTURE AND FUNCTION, MAINTENANCE STANDARD…………………………………………………………….10-1 20 TESTING AND ADJUSTING ……………………………………………………………..20-1 30 DISASSEMBLY AND ASSEMBLY ………………………………………………….30-1 90 OTHERS ……………………………………………………………………………………………………..90-1 GENERAL This section lists the general machine dimensions, performance specifications, component weights, and fuel, coolant and lubricant specification charts. STRUCTURE, FUNCTION AND MAINTENANCE STANDARD This section explains the structure and function of each component. It serves not only to give an understanding of the structure, but also serves as reference material for troubleshooting. TESTING, ADJUSTING AND TROUBLESHOOTING This section explains checks to be made before and after performing repairs, as well as adjustments to be made at completion of the checks and repairs. Troubleshooting charts correlating Problems to Causes are also mention in this section. DISASSEMBLY AND ASSEMBLY KOMATSU Excavator This section explains the order to be followed when removing, installing, disassembling or assembling each component, as well as precautions to be taken for these operations. When the load is increased, the engine speed may lower or the engine speed may be normal and working speed may be lower. If this trouble occurs and the pump discharge pressure and LS differential pressure are normal, adjust the pump PC valve according to the following procedure. a Before loosening locknut, be sure to make match marks. 1. Loosen locknut (1) and adjust with adjustment screw (2). a Since the PC valve is of eccentric type, in which direction the adjustment screw should be turned to increase the absorption torque is unknown. Accordingly, monitor the engine speed when turning the adjustment screw. 2. After adjusting, tighten locknut (1).