26
39 GW
6
59
20A
108 LW
61
B
90
58
1
2WR
B
109 LO
M
B
5R
YB 84
B
RW 66 67
51 YG
85
8
5R
64 BAT
11 WY 54
P
IG
L
106 W 105 LG
101
GW
71
M
72
81 9
68
52 YR
IC REG
B
YB
69
50 GW
81 O
1
55
52 2
70
82
5
WY 54 PL
1
B
6
B
WG 5
51 31
W 70 2BR
4
55 YL B
10
47 3LY
53
107 WR
HOLD
B
B
92 L
PULL
50
84 6
100 Lg E
49
2B
85 4
B
RG
15
12 20
R +1
11
2
YB
B
GAUGE CLUSTER
5
87 1.25 BrR
86
B
LgR
B 79
21
3
4 WG
6
1
WY
RG
1 WY
5
POSITION
POSTION
10A
45
38 8
2R
27 8
71 3Y 7
2RB 72 L POSITON
PREHEATING
11 WY
E 42
5R
POSITION
6
43 R2
40
7
ACC
2RB
5
2W 5
70
2BR
B
3
ON
25
51 YG
86 LgR
E
3
50 GW 48 LgB
B 2
3
YG
3
YG
FUEL METER
10
11
TERMO METER
13
ILLUMINATION
1
12
6
56 YB
26
32 39
GW
B
52 YR 63
B
BY
64 LW
A
28
B
33 B
60 GY
AIR FILTER RESTRICTION 9
1 WY
M
M
P1
21 WB
H
B
YB
2
YB
19
P2
61 LB
16 RW
13 BW
C
W
15 YG
W
72 L
BR
2W
5
TERMINAL
58 GB
22 BR
E
5
2
CHARGE
20 G
39
47 3LY
2
6
L
WG
47 3LY
R1
4
ENG. OIL PRESS.
1 WY
5R WASHER ON
8
6
57 LB
OFF
L 8
OFF
AC
B
EMPTY
19 LB
WASHER
P
C
START
ON
OFF
TERMINAL
7
POSITION
S
B
TWO-SPEED
5
18 LY
M 8
WG
ENG. WATER TEMP.
L
14 2WR
3R
6
B
E
4
37 6
22
POSITION
18
WG
2W
3
B
1.25 YG
17
44
30A
3
B
17 PB
6
ENG. STOP SOL.
HORN, ROOM LAMP 4
WORK LIGHT 2RG
B
HI
30A
78
1
2
LO
30A
16
14
13
OFF
2YG
2
3
RELAY,SOL
RADIO, HEATER, WIPER
81 O
B
M
57
B 30A
- B +B L
91
1
77
M
R B
M
Y S
46
WY 1.25 YB
86
83
B
30A
86
47 9
2
90
7
60
62
55 YL B
54 PL
83
73
2
9
63
M
WY
LR
2
S
1
88
B 14
113 OW
82
80
75
20R
20B
111 GL
1
87
76
89 1.25 RL
1
110 G
B
91 1.25 O
20A
4 1.25 RG
4
56 B
65
74
112 WR
8
29
36 23
41
4
86
LgR
H EM
1.25
49 P 2
48 2B
E
6
2B
WG
1
4
30
61 LB 45 BW
B
HOLD B
6
2 3 5
HOLD
43
34
YB
Lg
46 WB
24 2
35 B
COMPONENTS
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
BATTERY (E-13) STARTER MOTOR (M-1) DIODE (D-1) AIR HEATER (E-8) GENERATOR (E-2) ENGINE STOP SOLENOID (SV-3) ENGINE WATER TEMP SWITCH (SW-5) ENGINE OIL PRESS SWITCH (SW-6) COOLANT THERMO SENSOR (SE-2) AIR FILTER RESTRICTION SWITCH (SW-14) NORTH AMERICAN AND AUSTRAILIA: STANDARD HEATER (OPTIONAL) (E-12) WIPER MOTOR (FOR CAB) (M-2) WASHER MOTOR (FOR CAB) (M-3) HORN (E-3) CAB LAMP (L-1)
16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31.
RADIO (FOR CAB OPTION) (E-10) HORN SWITCH (SW-7) GAUGE CLUSTER (E-6) CHARGE INDICATOR RELAY (R-8) DIODE (D-2) FUEL SENSOR (SE-1) INDICATOR (OPTION) (C-8) (NOT SHOWN) DIODE (D-3) DIODE (D-4) BOOM WORKING (L-2) LIGHT LEFT (55W) LEVER LOCK SWITCH (SW-9) DIODE (D-12) DECEL RELAY (R-3) CRANE TIMER RELAY (OPTION) (R-20) (NOT SHOWN) DECEL SWITCH (SW-11) DIODE (D-13)
32. OPERATING LEVER LOCK SOLENOID (SV-1) 33. DECEL MOTOR (M-4) 34. TWO-SPEED SELECT SOLENOID (SV-2). 35. TWO-SPEED SELECT SW (SW-3). 36. SEQUENCE BOX (E-14) 37. WORKING LIGHT SWITCH (SW-2) 38. HEATER SWITCH (OPTION) (SW-10) 39. WIPER WASHER SWITCH (FOR CAB) (SW-4) 40. ENGINE STOP RELAY (R-7) 41. TIMER UNIT (R-6) 42. SAFETY RELAY (R-2) 43. KEY SWITCH (SW-1) 44. BATTERY RELAY (R-1) 45. FUSE BOX (E-1) 46. FEED PUMP (M-6) 47. FUSIBLE LINK (45A) (E-4)
48. HOUR METER (E-26) 49. SLEW/SWING PRESERVATION RELAY (R-23) (NORTH AMERICA: STANDARD) 50. SLEW/SWING LEVER PRESSURE SWITCH LEFT (SW-30) 51. SLEW/SWING LEVER PRESSURE SWITCH RIGHT (SW-31) 52. SWITCH SELECT RELAY (R-22) 53. SLEW/SWING SELECT SWITCH (SW-28) 54. SLEW/SWING SELECT RELAY (R-14) 55. SLEW/SWING SELECT SOLENOID (SV-12) 56. NIBBLER OPEN SWITCH (SW-33) 57. DIODE (D-14) 58. NIBBLER OPEN RELAY (R-24) 59. NIBBLER OPEN SOLENOID (SV-9) 60. NIBBLER CLOSE SOLENOID (SV-10) 61. NIBBLER CIRCUIT 62. LEVER CLOSE RELAY (R-25)
CIRCUIT DIAGRAM LEGEND
SHOWS CIRCUIT CROSSING NOT CONNECTED
SHOWS CIRCUIT CONNECTED
54 COMPONENT NUMBER
COMPONENT OUTLINE
6
6
TO
FROM
NUMBER REFERS TO CONTINUATION OF A CIRCUIT
63. 64. 65. 66. 67. 68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79. 80.
NIBBLER CLOSE SWITCH (SW-34) SLEW SWING CIRCUIT AIR CONDITIONER (FOR CAB OPTION) CONDENSER SPEED SHIFT RELAY (R-10) CONDENSER SPEED SHIFT SWITCH (SW-16) CONDENSER RELAY (R-11) CONDENSER MOTOR (E-17) COMPRESSOR (E-18) HI, LOW PRESSURE SWITCH (SW-15) COOLING UNIT (E-16) POWER SHIFT SOLENOID (SV-5) FUSE (E-15) COOLER RELAY (R-13) BLOWER MOTOR WORK LIGHT CIRCUIT WORK LIGHT RELAY (R-9) CAB/CANOPY WORKING LIGHT (L-5) TRAVEL ALARM SELECTOR SWITCH (SW-23)
WIRE IDENTIFICATION 6 FROM FUSE PANEL
INDICATES EXTERNAL GROUND
INDICATES INTERNALLY GROUNDED COMPONENT
6 WIRE NUMBER WIRE SIZE
2 R WIRE COLOR
B . . Black Br . . Brown G . . Green Gr. . Gray L. . . Blue
81. 82. 83. 84. 85. 86. 87. 88. 90. 91.
TRAVEL ALARM NORTH AMERICAN OPTION TRAVEL RIGHT (FORWARD) PRESSURE SWITCH (SW-24) TRAVEL RIGHT (REVERSE) PRESSURE SWITCH (SW-25) TRAVEL LEFT (FORWARD) PRESSURE SWITCH (SW-26) TRAVEL LEFT (REVERSE) PRESSURE SWITCH (SW-27) TRAVEL ALARM (E-20) TRAVEL ALARM EUROPEAN OPTION POWER SOCKET (E-7) ENGINE INST PANEL AND RELAY ASSY. (PART IN RELAY CONSOLE)
NOTES Lg. . Light Green O . . Orange P . . Pink R . . Red Sb . Sky Blue
V . . Violet W . . White Y . . Yellow
1. Diagram shown with vehicle parked, power OFF, and controls in OFF or NEUTRAL position.
ELECTRICAL SCHEMATIC EH50.B HYDRAULIC EXCAVATORS Additional copies of this Hydraulic and Electrical Schematic can be ordered through Technical Publications Distribution System. The Part Number is 6-78850
GROUND BCO4N075
NEUTRAL CIRCUIT
TRAVEL CIRCUIT - TRAVEL FORWARD OPERATION AT TRAVEL 2ND SPEED 4 A1G A1
R1
A1
A2
D2
P
P
P3
401 A3
A2 A2G A4
407
404
407
406
P2
T
T1 13-1
402 P2
B
A R
A
3
23
403
T
6
7
407
P3
30
15
P2
9
4
401
B
A
A
3
23
403
6 402
302
24
301 407
7
407
P3
D1 P2
30
15 R2 A
R1
PP 305
305
DR
B
A
T
29
R1
PP 305
305
C
A C F E
PG
DR
B
A
T
29 A
B
28
303
D B D P G
29
304
B
8
10
C PG
304
D2
S1
303
D A C F E
B
304
B
8
22
5
405
19
R2
10
A
D1
404
406
405
304
D2
A
29
P2
408
408
403
P
P1
S1
B D P G
407
406
402
302
24
D1 P2
407
404
T1
301 407
401 A3
A2 A2G A4
13-1
405
19
P
P
P3
1
402
405
P
P1
B
D2
13
408
408
403
A1G A1
R1
A1
A2
22
5
13 1
4
401
404
406
9
4
D1
B
28 27
P
27
P
T A2B2 A1 B1
T A2B2 A1 B1
T
T PP P2 P SW31
PP P2 P SW31
P1 P SW30
25
P1 P SW30
25
16
16
3 7 4 8
21
B9
Pa9
A9
2 Pb8
Dr B8
A8 Pa8
B7
A7 Pa7
P1
P2
Pa6
A6
B6
Pa5
A5
B5
Pa4
Pa3
B4
A4
A3
P3 B2
B3
A2 Pa2
B1
3 7 4 8 D
A1 Pa1
20
21
B9
11 2 4
3
1
2 4
Dr B8
A8 Pa8
B7
A7 Pa7
P1
P2
Pa6
A6
B6
Pa5
A5
B5
Pa4
Pa3
B4
A4
A3
P3 B2
B3
2 4
MRV3
17
26
204
203
204
204 P
P
T
204
T
201 MRV T
T
P 204
2 Pb8
T2
Pb9
Pb6
Pb7
Pb5
Pb4
T1
Pb3
Pb2
P T2
Pb1
Pb8
Pb9
Pb6
Pb7
Pb5
Pb4
T1
Pb3
3
4
1
2
A1G A1
R1
D2
P
P
P3
401 A3
A2 A2G A4
407
404
407
406
P2
1
5
T1 13-1
402
B
B
A
A
P1
3
23
T
6
7 P3
30
15
D1
12
9
4
401
404
406
P P2
B
A
A
3
23
403
6 402 405
302
24
301
19
407
7
407
P3
D1 P2
30
15 R2 A
R1
PP 305
305
DR
B
A
T
29
303
R1
PP D
B D P G
29
304
B
8
10
C PG
304
D2
S1
303
D A C F E
22
5
304
B
8
10
B
405
304
D2
A
A
P2
408
408
403
R2
B D P G
407
406
402
P1
S1
29
407
404
T1
302
24
407
D1 P2
401 A3
A2 A2G A4
13-1
301 407
P
P
P3
1
402 405
19
D2
13
403
405
A1G A1
R1
A1
A2
22
408
408
403
4
401
404
406
9
4
D1
13
P2
3
4
1
BUCKET CIRCUIT - BUCKET DIGGING OPERATION 4
P1
T
Pb1
12
SLEWING CIRCUIT - SLEWING LEFT OPERATION
T T1
Pb2
Pp1
2
A1
T
204
T
Pp1
A2
P
T
204
14
2 P
T2
P
201 MRV
204
14
11
3
1
MRV3
203
18
204 P
2 4
202
204
203
3
1
204
203
26
D
A1 Pa1
11
202
17
B1
206
204
18
A2 Pa2
3 7 4 8
11
3
1
2 Pb8
20
3 7 4 8
206
Pa9
A9
305
305
C
A C F E
PG
DR
B
A
T
29 A
B
B
28
28 27
P
27
P
T A2B2 A1 B1
T A2B2 A1 B1 T
T
PP
PP P2 P SW31
P2 P SW31
P1 P SW30
25
P1 P SW30
25
16
16 3 7 4 8
3 7 4 8
21
B9
A9
Pa9
2 Pb8
Dr B8
A8 Pa8
B7
A7 Pa7
P1
P2
Pa6
A6
B6
Pa5
A5
B5
Pa4
A4
B4
Pa3
A3
P3 B2
B3
A2 Pa2
B1
D
A1 Pa1
20
21
B9
11 2 4
3
1
2 4
3
1
Pa9
2 Pb8
Dr B8
A8 Pa8
B7
A7 Pa7
P1
P2
Pa6
A6
B6
Pa5
A5
B5
Pa4
A4
B4
Pa3
A3
P3 B2
B3
2 4
206
MRV3
17
26
204 P
P
T
204
T
201 MRV P 204
2 Pb9
T2
Pb8
Pb7
Pb6
Pb5
Pb4
Pb3
T1
Pb2
T
P T2
Pb1
Pb9
T2
Pb8
Pb6
Pb7
Pb5
Pb4
Pb3
T1
8. 9. 10. 11. 12. 13. 14.
SWING CYLINDER DOZER CYLINDER SWIVEL JOINT PILOT VALVE (ATT) PILOT VALVE (TRAVEL) SOLENOID VALVE PILOT VALVE (DOZER)
15. 16. 17. 18. 19. 20. 21.
COMPONENT IDENTIFICATION SHUTTLE VALVE 22. NIBBLER CYLINDER MULTI CONTROL VALVE 23. STOP VALVE RETURN FILTER (ELEMENT) 24. SELECTOR VALVE SUCTION STRAINER 25. OIL COOLER INLINE FILTER 26. HYDRAULIC OIL TANK CHECK VALVE 27. SOLENOID VALVE HYDRAULIC RESERVOIR VENT 28. SOLENOID VALVE
29. ORIFICE
Pb2
T
Pb1
Pp1
2
PUMP ASSEMBLY CONTROL VALVE SLEWING MOTOR TRAVEL MOTOR BOOM CYLINDER / CANOPY CAB ARM CYLINDER BUCKET CYLINDER
T
204
T
Pp1
1. 2. 3. 4. 5. 6. 7.
P
T
204
14
2 P
T2
P
201 MRV
204
14
11
204
203
204
T
3
1
MRV3
203
18
204 P
2 4
202
204
203
3
1
204
203
26
D
A1 Pa1
11
11
202
17
B1
3 7 4 8
204
18
A2 Pa2
20
3 7 4 8
206
A9
1
4
3
2
12
1. 2. 3. 4. 5. 6.
NOTES 201 (MAIN RELIEF VALVE P1,P2) 23.0 MPa (3340 psi) 202 (MAIN RELIEF VALVE P3) 23.0 MPa (3340 psi) 203 (OVERLOAD RELIEF VALVE) 27.5 MPa (4000 psi) 204 (OVERLOAD RELIEF VALVE) 25.5 MPa (3700 psi) 304 (SLEW RELIEF VALVE) 21.0 MPa (3050 psi) 13-1 (PILOT RELIEF VALVE) 3.5MPa (508 psi)
1
4
3
12
HYDRAULIC SYMBOLS PRESSURE PILOT MAIN PRESSURE PILOT SEC PRESSURE CASE DRAIN COMPONENT
CHECK VALVE
54 COMPONENT NUMBER
SHOWS CIRCUIT CROSSING NOT CONNECTED
SHOWS CIRCUIT CONNECTED
FILTER OR SCREEN
HYDRAULIC SCHEMATIC EH50.B HYDRAULIC EXCAVATORS Additional copies of this Hydraulic and Electrical Schematic can be ordered through Technical Publications Distribution System. The part number is 6-78850
RESTRICTOR
OIL COOLER BC04N072
BOOM CIRCUIT - BOOM-UP OPERATION
ARM CIRCUIT - ARM-IN OPERATION 4 A1G A1
R1
A1
A2
D2
P
P
P3
401 A3
A2 A2G A4
407
404
407
406
P2
D1
T
T1 13-1
402 P2
B
A R
A
3
23
403
T
6
7
407
P3
30
15
P2
9
4
401
B
A R
A
3
23
403
6 402
302
24
301 407
7
407
P3
D1 P2
30
15 R2 A
R1
PP 305
305
DR
B
A
T
29
R1
PP 305
305
C
A C F E
PG
DR
B
A
T
29 A
B
28
303
D B D P G
29
304
B
8
10
C PG
304
D2
S1
303
D A C F E
B
304
B
8
22
5
405
19
R2
10
A
D1
404
406
405
304
D2
A
29
P2
408
408
403
P
P1
S1
B D P G
407
406
402
302
24
D1 P2
407
404
T1
301 407
401 A3
A2 A2G A4
13-1
405
19
P
P
P3
1
402
405
P
P1
B
D2
13
408
408
403
A1G A1
R1
A1
A2
22
5
13 1
4
401
404
406
9
4
B
28 27
P
27
P
T A2B2 A1 B1
T A2B2 A1 B1
T
T PP P2 P SW31
PP P2 P SW31
P1 P SW30
25
P1 P SW30
25
16
16
3 7 4 8
21
B9
Pa9
A9
2 Pb8
Dr B8
A8 Pa8
B7
A7 Pa7
P1
P2
Pa6
A6
B6
Pa5
A5
B5
Pa4
Pa3
B4
A4
A3
P3 B2
B3
A2 Pa2
B1
3 7 4 8 D
A1 Pa1
20
21
B9
11 2 4
3
1
2 4
Dr B8
A8 Pa8
B7
A7 Pa7
P1
P2
Pa6
A6
B6
Pa5
A5
B5
Pa4
Pa3
B4
A4
A3
P3 B2
B3
2 4
MRV3
17
26
204
203
204
204 P
P
T
204
T
201 MRV T
T
P 204
2 Pb8
T2
Pb9
Pb6
Pb7
Pb5
Pb4
T1
Pb3
Pb2
P T2
Pb1
Pb8
T2
Pb9
Pb6
Pb7
Pb5
Pb4
T1
Pb3
3
4
1
2
A1G A1
R1
D2
P
P
P3
401 A3
A2 A2G A4
407
404
407
406
P2
D1
1
5
T1 13-1
402
B
B
A
A
P
3
23
T
6
7 P3
30
15
D1
12
9
4
401
404
406
P P2
B
A
A
3
23
403
6 402 405
302
24
301
19
407
7
407
P3
D1 P2
30
15 R2 A
R1
PP 305
305
DR
B
A
T
29
303
R1
PP D
B D P G
29
304
B
8
10
C PG
304
D2
S1
303
D A C F E
22
5
304
B
8
10
B
405
304
D2
A
A
P2
408
408
403
R2
B D P G
407
406
402
P1
S1
29
407
404
T1
302
24
407
D1 P2
401 A3
A2 A2G A4
13-1
301 407
P
P
P3
1
402 405
19
D2
13
403
405
A1G A1
R1
A1
A2
22
408
408
403
4
401
404
406
9
4
13
P2
3
4
1
DOZER CIRCUIT - DOZER-DOWN OPERATION 4
P1
T
Pb1
12
SWING CIRCUIT - BOOM SWING-LEFT OPERATION
T
Pb2
Pp1
2
A1
T
204
T
Pp1
A2
P
T
204
14
2 P
T2
P
201 MRV
204
14
11
3
1
MRV3
203
18
204 P
2 4
202
204
203
3
1
204
203
26
D
A1 Pa1
11
202
17
B1
206
204
18
A2 Pa2
3 7 4 8
11
3
1
2 Pb8
20
3 7 4 8
206
Pa9
A9
305
305
C
A C F E
PG
DR
B
A
T
29 A
B
B
28
28 27
P
27
P
T A2B2 A1 B1
T A2B2 A1 B1 T
T
PP
PP P2 P SW31
P2 P SW31
P1 P SW30
25
P1 P SW30
25
16
16 3 7 4 8
3 7 4 8
21
B9
A9
Pa9
2 Pb8
Dr B8
A8 Pa8
B7
A7 Pa7
P1
P2
Pa6
A6
B6
Pa5
A5
B5
Pa4
A4
B4
Pa3
A3
P3 B2
B3
A2 Pa2
B1
D
A1 Pa1
20
21
B9
11 2 4
3
1
2 4
3
1
Pa9
2 Pb8
Dr B8
A8 Pa8
B7
A7 Pa7
P1
P2
Pa6
A6
B6
Pa5
A5
B5
Pa4
A4
B4
Pa3
A3
P3 B2
B3
2 4
206
MRV3
17
26
204 P
P
T
204
T
201 MRV P 204
2 Pb9
T2
Pb8
Pb7
Pb6
Pb5
Pb4
Pb3
T1
Pb2
T
P T2
Pb1
Pb9
T2
Pb8
Pb6
Pb7
Pb5
Pb4
Pb3
T1
8. 9. 10. 11. 12. 13. 14.
SWING CYLINDER DOZER CYLINDER SWIVEL JOINT PILOT VALVE (ATT) PILOT VALVE (TRAVEL) SOLENOID VALVE PILOT VALVE (DOZER)
15. 16. 17. 18. 19. 20. 21.
COMPONENT IDENTIFICATION SHUTTLE VALVE 22. NIBBLER CYLINDER MULTI CONTROL VALVE 23. STOP VALVE RETURN FILTER (ELEMENT) 24. SELECTOR VALVE SUCTION STRAINER 25. OIL COOLER INLINE FILTER 26. HYDRAULIC OIL TANK CHECK VALVE 27. SOLENOID VALVE HYDRAULIC RESERVOIR VENT 28. SOLENOID VALVE
29. ORIFICE
Pb2
T
Pb1
Pp1
2
PUMP ASSEMBLY CONTROL VALVE SLEWING MOTOR TRAVEL MOTOR BOOM CYLINDER / CANOPY CAB ARM CYLINDER BUCKET CYLINDER
T
204
T
Pp1
1. 2. 3. 4. 5. 6. 7.
P
T
204
14
2 P
T2
P
201 MRV
204
14
11
204
203
204
T
3
1
MRV3
203
18
204 P
2 4
202
204
203
3
1
204
203
26
D
A1 Pa1
11
11
202
17
B1
3 7 4 8
204
18
A2 Pa2
20
3 7 4 8
206
A9
1
4
3
2
12
1. 2. 3. 4. 5. 6.
NOTES 201 (MAIN RELIEF VALVE P1,P2) 23.0 MPa (3340 psi) 202 (MAIN RELIEF VALVE P3) 23.0 MPa (3340 psi) 203 (OVERLOAD RELIEF VALVE) 27.5 MPa (4000 psi) 204 (OVERLOAD RELIEF VALVE) 25.5 MPa (3700 psi) 304 (SLEW RELIEF VALVE) 21.0 MPa (3050 psi) 13-1 (PILOT RELIEF VALVE) 3.5MPa (508 psi)
1
4
3
12
HYDRAULIC SYMBOLS PRESSURE PILOT MAIN PRESSURE PILOT SEC PRESSURE CASE DRAIN COMPONENT
CHECK VALVE
54 COMPONENT NUMBER
SHOWS CIRCUIT CROSSING NOT CONNECTED
SHOWS CIRCUIT CONNECTED
FILTER OR SCREEN
HYDRAULIC SCHEMATIC EH50.B HYDRAULIC EXCAVATORS Additional copies of this Hydraulic and Electrical Schematic can be ordered through Technical Publications Distribution System. The part number is 6-78850
RESTRICTOR
OIL COOLER BC04N073
NIBBLER AND BREAKER CIRCUIT - NIBBLER CLOSE OPERATION
COMBINED OPERATION CIRCUIT - TRAVEL FORWARD, 1ST SPEED / DOZER-DOWN OPERATION 4
A1G A1
R1
A1
A2
D2
P
P
P3
401 A3
A2 A2G A4
407
404
407
406
P2
T
T1 13-1
402 P2
B
A R
A
3
23
403
T
6
7
407
P3
P2
30
15
29
6 402
302
24
301
7
407
30
15 R2 A
R1
PP 305
305
DR
B
A
T
R1
PP 305
305
C
A C F E
PG
DR
B
A
T
29 A
B
28
303
D B D P G
29
304
B
8
10
C PG
304
D2
P3
S1
29 A
A
D1 P2
303
D A C F E
A R
3
23
403
304
B
8
10
B
407
R2 A
22
5
405
19
304
D2
B
405
P
P1
S1
B D P G
401
404
406
9
4
D1
P2
408
408
403
402
302
24
D1 P2
407
406
T1
301 407
407
404
13-1
405
19
A3
A2 A2G A4
1
402
405
P
P1
B
P
P
P3
13
408
408
403
D2
401
A1G A1
R1
A1
A2
22
5
13 1
4
401
404
406
9
4
D1
B
28 27
P
27
P
T A2B2 A1 B1
T A2B2 A1 B1
T
T PP P2 P SW31
PP P2 P SW31
P1 P SW30
25
P1 P SW30
25
16
16
3 7 4 8 B9
Pa9
A9
2 Pb8
Dr B8
A8 Pa8
B7
A7 Pa7
P1
P2
Pa6
A6
B6
Pa5
A5
B5
Pa4
Pa3
B4
A4
A3
P3 B2
B3
A2 Pa2
B1
D
A1 Pa1
20
21
B9
11 2 4
3
1
2 4
Dr B8
A8 Pa8
B7
A7 Pa7
P1
P2
Pa6
A6
B6
Pa5
A5
B5
Pa4
Pa3
B4
A4
A3
P3 B2
B3
2 4
MRV3
17
26
204 P
P
T
204
T
201 MRV P 204
2 Pb8
T2
Pb9
Pb6
Pb7
Pb5
Pb4
T1
Pb3
Pb2
T
P T2
Pb1
Pb8
T2
Pb9
Pb6
Pb7
Pb5
Pb4
T1
Pb3
Pb2
3
4
1
2
12
COMBINED OPERATION CIRCUIT - TRAVEL FORWARD, 1ST SPEED / BOOM-UP OPERATION
A1G A1
R1
A1
A2
P
P
P3
A3
407
404
407
406
P2
T
T1 402 P2
B
B
22
5
A
A
T
3
402
302
24
A
B
P
C
H
SHUTTLE VALVE
D 301
19
407
7
407
P3
D1 P2
30
A
15
S1
Pb8
304
B
8
Pb7
303 PP
ATT PILOT VALVE (L.H.) 305 PG
DR
B
i8 j
A
T
29
4
P 1
i5 j
B
3
28 27
P
ATT PILOT VALVE (R.H.)
2
i4 j 4
i6 j i1 j
T
i7 j
3
i3 j
T PP P2
i2 j
P 1
T A2B2 A1 B1
SLEWING MOTOR
2
P SW30
16 2 Pb8
Dr B8
A8 Pa8
B7
A7 Pa7
P1
P2
Pa6
A6
B6
Pa5
A5
B5
Pa4
A4
B4
Pa3
A3
P3 B2
B3
A2 Pa2
B1
3 BOOM UP BOOM DOWN 4 7 ARM IN ARM OUT 8 BUCKET DUMP BUCKET DIGGING
SLEW (Swing) LEFT SLEW (Swing) RIGHT
B T DR A
Pb3
A7
H
Pa8
R
SWING CYLINDER
Pa7
20 11 3
1
ARM
B3
H A6
ARM CYLINDER
B1 A1 B2 A2
P1 P2
2 4
3
1
BOOM SWING LEFT SLEW LEFT BOOM SWING RIGHT SLEW RIGHT
Pa5
A5 A4
Pa4
H Pa3
A3
Pb2
SLEW
B2
Pb1
DOZER
B1
R
NIBBLER CYLINDER
P3
T1
R
Pa6
SELECTOR VALVE A2 A1
RETURN FILTER CHECK HYDRAULIC OIL TANK VALVE
Pa2 Pa1
CONTROL VALVE
SOLENOID VALVE
SLEW RIGHT
3 7 4 8
2 4
P2
TRAVEL B6 RIGHT B5 SWING
Pp1
T
D
A1 Pa1
206
A8
B7
Pb4 SERVICE B4
3 7 4 8 Pa9
Pb5
T
PB PP
A9
Pa9
PP
25
B9
Pb6
MULTI CONTROL VALVE
P1
P SW31
21
BOOM CYLINDER
A9
P1
305
C
A C F E
TRAVEL LEFT
R
R1
D B D P G
A
B
T2 B9
BUCKET BOOM Pb8' Dr B8
R2
10 29
Pb9
304
D2
A
R
BUCKET CYLINDER
T
P NIBBLER & BREAKER SOLENOID VALVE
6 405
H
4 2
23
403
405
P
P1
12
TRAVEL PILOT VALVE
3 1
408
408
403
13-1
3
(LEFT) (RIGHT)
401
404
406
9
4
D1
13 1
4
1
SCHEMATIC PIPING FOR HYDRAULIC SYSTEM
401 A2 A2G A4
T
Pb1
Pp1
2
D2
T
204
T
Pp1
4
P
T
204
14
2 P
T2
P
201 MRV
204
14
11
204
203
204
T
3
1
MRV3
203
18
204 P
2 4
202
204
203
3
1
204
203
26
D
A1 Pa1
11
202
17
B1
206
204
18
A2 Pa2
3 7 4 8
11
3
1
Pb8
20
3 7 4 8
206
2
Pa9
A9
BREAKER
21
3 7 4 8
SUCTION STRAINER
SLEW LEFT
11
IN
202
OUT
204 MRV3
203
18
17
26
A3
204
203
204
P
P
T
S E F C A
204
14
204
2
P T2
Pb9
T2
Pb8
Pb7
Pb6
Pb5
Pb4
ENGINE
FILTER
HYDRAULIC PUMP
T
201 MRV T
DOZER PILOT VALVE
A1 A2
204
P
A4
Pb3
T1
Pb2
G
P
B D SWIVEL JOINT
DOZER CYLINDER
T
OIL COOLER
P 2
A2 1
4
3
SOLENOID VALVE
PILOT CIRCUIT
12
D1 A B
FORWARD P
1
A1
H
Pp1
2
T
P1
P2
Pb1
R
RELIEF VALVE
D2 B
FORWARD
BACKWARD
BACKWARD
TRAVEL 2-SPEED T1
LEVER LOCK
MAIN CIRCUIT
A SUPPLY / RETURN (DRAIN) CIRCUIT
TRAVEL MOTOR (LEFT)
1. 2. 3. 4. 5. 6. 7.
PUMP ASSEMBLY CONTROL VALVE SLEWING MOTOR TRAVEL MOTOR BOOM CYLINDER / CANOPY CAB ARM CYLINDER BUCKET CYLINDER
8. 9. 10. 11. 12. 13. 14.
SWING CYLINDER DOZER CYLINDER SWIVEL JOINT PILOT VALVE (ATT) PILOT VALVE (TRAVEL) SOLENOID VALVE PILOT VALVE (DOZER)
15. 16. 17. 18. 19. 20. 21.
COMPONENT IDENTIFICATION SHUTTLE VALVE 22. NIBBLER CYLINDER MULTI CONTROL VALVE 23. STOP VALVE RETURN FILTER (ELEMENT) 24. SELECTOR VALVE SUCTION STRAINER 25. OIL COOLER INLINE FILTER 26. HYDRAULIC OIL TANK CHECK VALVE 27. SOLENOID VALVE HYDRAULIC RESERVOIR VENT 28. SOLENOID VALVE
29. ORIFICE
1. 2. 3. 4. 5. 6.
NOTES 201 (MAIN RELIEF VALVE P1,P2) 23.0 MPa (3340 psi) 202 (MAIN RELIEF VALVE P3) 23.0 MPa (3340 psi) 203 (OVERLOAD RELIEF VALVE) 27.5 MPa (4000 psi) 204 (OVERLOAD RELIEF VALVE) 25.5 MPa (3700 psi) 304 (SLEW RELIEF VALVE) 21.0 MPa (3050 psi) 13-1 (PILOT RELIEF VALVE) 3.5MPa (508 psi)
TRAVEL MOTOR (RIGHT)
HYDRAULIC SYMBOLS PRESSURE PILOT MAIN PRESSURE PILOT SEC PRESSURE CASE DRAIN COMPONENT
CHECK VALVE
54 COMPONENT NUMBER
SHOWS CIRCUIT CROSSING NOT CONNECTED
SHOWS CIRCUIT CONNECTED
FILTER OR SCREEN
HYDRAULIC SCHEMATIC EH50.B HYDRAULIC EXCAVATORS Additional copies of this Hydraulic and Electrical Schematic can be ordered through Technical Publications Distribution System. The part number is 6-78850
RESTRICTOR
OIL COOLER BC04N074