Pages from 9803-9800 – JCB JS290 Tier III Auto Hydraulic Excavator Service Manual
Complete workshop & service manual with electrical wiring diagrams for JCB JS290 Tier III Auto Hydraulic Excavator. It’s the same service manual used by dealers that guaranteed to be fully functional and intact without any missing page.
This JCB JS290 Tier III Auto Hydraulic Excavator service & repair manual (including maintenance, overhaul, disassembling & assembling, adjustment, tune-up, operation, inspecting, diagnostic & troubleshooting…) is divided into different sections. Each section covers a specific component or system with detailed illustrations. 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. The printer-ready PDF documents work like a charm on all kinds of devices.
9803-9800 – JCB JS290 Tier III Auto Hydraulic Excavator Service Manual.pdf
EXCERPT:
Service Manual
JS290 – Tier III Auto
Section 1 – General Information
Section 2 – Care and Safety
Section 3 – Routine Maintenance
Section B – Body & Framework
Section C – Electrics
Section E – Hydraulics
Section F – Transmission
Section J – Track and Running Gear
Section K – Engine
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Cushion Control Off
Fig 6. Cushion Control Off
When the cushion switch is illuminated, the cushion solenoid is energised and pilot pressure is fed to port S on the cushion valve. The two inner left and right cushion spools are both pushed into the centre of the outer spool, so that the unrestricted galleries X and the cushion valve spools are open to allow the pilot outputs from the hand controller to pass through the valve unrestricted, to the main control valve. When the dipper hand controller is operated, pilot pressure from the lever to port A, moves the outer spool to the right and pilot pressure is fed to the dipper spool in the control valve, via port C. At the conclusion of the hand controller operation, the returning pilot oil, goes straight back to the lever, with no restriction.
There is no cushioning effect. Hot oil from port R returns to tank via the dipper hand controller, as it does in the warming circuit in the neutral position. K Fig 6. ( T E-117)
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