Complete digital official shop manual contains service, maintenance, and troubleshooting information for the Komatsu PC20R, PC27R, PC27MR, PC30MR, PC35MR, PC40MR, PC50MR Hydraulic Excavator. Diagnostic and repair procedures are covered in great detail to repair, maintain, rebuild, refurbish or restore your excavator like a professional mechanic in local service/repair workshop. This cost-effective quality manual is 100% complete and intact as should be without any missing pages. It is the same factory shop manual used by dealers that guaranteed to be fully functional to save your precious time.

This manual for Komatsu PC20R-8, PC27R-8, PC27MR-2, PC30MR-2, PC35MR-2, PC40MR-2, PC50MR-2 Hydraulic Excavator is divided into different sections. Each section covers a specific component or system and, in addition to the standard service procedures, includes disassembling, inspecting, and assembling instructions. A table of contents is placed at the beginning of each section. Pages are easily found by category, and each page is expandable for great detail. It is in the cross-platform PDF document format so that it works like a charm on all kinds of devices. You do not need to be skilled with a computer to use the manual.

"Shop Manual (WEBM000201).pdf"
298 pages
PC20R-8, PC27R-8 HYDRAULIC EXCAVATOR

"Shop Manual (SEBM032411).pdf"
630 pages
PC27MR-2, PC30MR-2, PC35MR-2, PC40MR-2, PC50MR-2 HYDRAULIC EXCAVATOR

"Operation & Maintenance Manual (WEAM000101).pdf"
196 pages
PC20R-8, PC27R-8 HYDRAULIC EXCAVATOR

EXCERPT:

STRUCTURE, FUNCTION AND MAINTENANCE STANDARD - OPERATION FOR EACH FUNCTION AND VALVE
L.H., R.H. TRAVEL JUNCTION CIRCUIT PC27MR, 30MR-2
1. When traveling in a straight line
FUNCTION
ï To compensate for any difference in the oil flow in the left and right travel circuits when traveling in a straight line, the junction circuit opens when the left and right travel spools are operated.
ï In this way, the flow of oil to the left and right travel motors is almost the same when traveling in a straight line, so there is no travel deviation.
ï When steering the machine, the difference in the load pressure returns the reducing valve of the travel valve on the inside of the turn and the opening of the notch in the travel junction valve spool becomes smaller, so the machine can be steered.
OPERATION
ï When left and right travel spools (1) are operated, the pump discharge flows from pump circuit PP and circuits PA to actuator circuits B.
ï When traveling in a straight line, to make actuator circuits PA equal, left and right reducing valves (2) are pushed to the right by the same amount, and notch a and the travel junction circuit are opened.
ï In this way, the left and right travel actuator circuits are interconnected by the travel junction circuit, so if any difference occurs in the flow of oil to the left and right travel motors, the compensation is carried out to prevent any deviation in travel.
2. Steering when traveling
OPERATION
• When traveling in a straight line, if left travel spool (L. H. 1) is returned to the neutral position and the steering is operated, a difference (R. H. B > L. H. B) is generated in the load pressure of left and right travel actuator circuits PA, and LS pressure PLS becomes the same pressure as R.
H. B.
• As a result, flow control valve (3) on the left travel side is pushed to the left by LS circuit PLS.
Because of this, the opening of the left notch a is made smaller, so it becomes possible to operate the steering when traveling.
• Damper b is provided in the circuit to damper any excessive characteristics in the opening or closing of the travel junction circuit if the spool is operated suddenly.
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