Komatsu Galeo PC138US-8 Shop Manual page 223

10 Structure, function and maintenance standard
P1 : From self pressure reducing valve
A1 : To PPC valve
A2 : To center swivel joint, port E1
A3 : To swing motor, port B
A4 : To control valve, port PS
A5 : To control valve, port PST
T : To hydraulic tank
ACC : To accumulator (for PPC circuit)
1. PPC lock solenoid valve
2. 2nd travel speed select solenoid valve
3. Swing holding brake solenoid valve
4. Pump merge-divider solenoid valve
5. Travel junction solenoid valve
Solenoid valve
6. Coil (ON/OFF type)
7. Push pin
8. Valve spool
9. Sleeve
10. Block
11. Plug
Check valve
12. Plunger
13. Plug
PC138US, USLC-8
Operation
Check valve
Installed between port (P) and PPC solenoid
q
valve. When the engine is stopped, plunger (1)
is pushed back to the left with spring (2) reac-
tion force, and ports (ACC) and (P) are closed
to maintain the pressure in the accumulator.
When the engine is running, plunger (1) is
q
pushed to the right with the pilot pressure that
is sent to port (P), and ports (P) and (ACC) are
interconnected.
SEN02550-01
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