Bucket Operating Circuit; Bucket Crowd Circuit; Bucket Dump Circuit; Swing Operating Circuit - Doosan DX140R Shop Manual

Bucket Operating Circuit

The bucket operating circuit includes the left main pump, the left
half of the control valve and the bucket cylinder. 350 kg/cm
(4,978 psi) overload relief valves at BKT and BKTD 1 ports of
the control valve protect the circuit and its components from
being damaged.

Bucket Crowd Circuit

When the bucket control lever is placed in the crowd position,
the bucket control valve spool on the right side of the control
valve opens and oil from rear main pump flows to the bucket
cylinder.

Bucket Dump Circuit

When the bucket control lever is put in the dump mode, the
bucket control valve spool in the right half of the control valve
opens to supply oil from the rear main pump to the cylinder.

Swing Operating Circuit

The swing operating circuit consists of the front main pump in
the pump assembly, the left half of the control valve and the
swing motor. To keep the upper works from coasting when the
swing control is in neutral, an electrical sensor in the control
circuit activates a valve to automatically engage a mechanical
brake.
Hydraulic System Troubleshooting, Testing and Adjustment
2
BKTD
TL
CONTROL
VALVE(R)
Figure 6
BKTD
TL
CONTROL
VALVE(R)
Figure 7
BUCKET
CYLINDER
BKT PILOT VALVE
PL
PUMP(R)
FG015080
BUCKET
CYLINDER
BKT
PILOT VALVE
PL
PUMP(R)
FG015081
SP001942
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