Komatsu ecot3 PC300LC-8 Shop Manual page 145

10 Structure, function and maintenance standard
1. Arm valve
2. R.H. travel valve
3. Swing valve
4. Boom valve
5. L.H. travel valve
6. Bucket valve
7. Boom Hi valve
8. Arm Hi valve
9. Service valve 1
10. Service valve 2
11. Arm spool
12. R.H. travel spool
13. Swing spool
14. Boom spool
15. L.H. travel spool
16. Bucket spool
17. Boom Hi spool
18. Arm Hi spool
19. Service spool 1
20. Service spool 2
21. Pressure compensation valve
22. Variable pressure compensation valve
23. Suction valve
24. Check valve (for boom regeneration circuit)
25. Check valve (for arm regeneration circuit)
26. LS shuttle valve
27. LS select valve
28. Merge-divider valve
29. Arm quick return valve
30. Self pressure reducing valve
31. Travel junction valve
32. Back pressure valve
33. Boom drift prevention valve
34. Boom Hi check valve
35. Main relief valve (bucket side)
Set pressure:
36.1 ± 0.25 MPa {367.5 ± 2.5 kg/cm
(112 l/min)
When digging force increased:
38.2 ± 0.25 MPa {389.5.5 ± 2.5 kg/cm
(110 l/min)
PC300, 350-8
36. Main relief valve (arm side)
Set pressure:
36.1 ± 0.25 MPa {367.5 ± 2.5 kg/cm
(112 l/min)
When digging force increased:
38.2.1 ± 0.25 MPa {389.5.5 ± 2.5 kg/cm
(110 l/min)
37. Unload valve (bucket side)
Cracking pressure:
3.1 ± 0.5 MPa {32 ± 5 kg/cm
38. Unload valve (arm side)
Cracking pressure:
3.1 ± 0.5 MPa {32 ± 5 kg/cm
39. Safety-suction valve
Set pressure:
17.2 ± 0.5 MPa {175 ± 5 kg/cm
40. Safety-suction valve
Set pressure:
38.2 ± 0.5 MPa {390 ± 5 kg/cm
41. 2-stage safety-suction valve
Set pressure:
1 stage: 21.1 ± 0.5 MPa {205 ± 5 kg/cm
2 stage: 17.2 ± 0.5 MPa {175 ± 5 kg/cm
42. 2-stage safety-suction valve
Set pressure:
1 stage: 28.4 ± 0.5 MPa {290 ± 5 kg/cm
2 stage: 14.7 ± 0.5 MPa {150 ± 5 kg/cm
43. Safety valve
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38.2 ± 0.5 MPa {390 ± 5 kg/cm
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