jcb JS300 Service Manual page 702

Section E - Hydraulics
Hydraulic System
Hydraulic Operation and Schematics
Bucket Opening
K Fig 10. ( T
For schematic, E-42).
Servo pressure from port 1 of the hand controller 48
selects the bucket open spool position via the pilot shuttle
block 46, port A8 and B8. Servo pressure at port Pa7 then
selects the bucket spool and upper pressure switch.
Flow from pump 2 is available to the bucket spool via the
parallel working gallery and boom over bucket priority
valve BBV.
At the spool the flow is diverted to port A7 of the main
control valve 14 to the bucket ram 13.
Returning oil enters the main control valve 14 at port B7
and is diverted by the bucket spool to the tank port.
Pressure in the neutral circuit drops after the selected
bucket spool, this is sensed at the port Ps2 and at the
pump bringing it into full flow.
E-41 9813/5100-1 E-41