SENR8916
16 Page
SENR8916
September 1995
350 and 350L Excavators
Heavy Lift
Hydraulic System (Attachment)
©
1995 Caterpillar
All Rights Reserved
Printed in U.S.A.
350:
2ZL171-Up
350L:
3ML685-Up
9FL420-Up
SENR8916
16 Page, B/W
1
6
3
5
3
4
2
2
1
4
5
6
HYDRAULIC SCHEMATIC
5I-4053
XA
PD
JL3
JL1
JR3
JR1
JR2
(REV)
( FWD )
TRT
TLP
TLA1
TLA2
MA
G
A
ST2
SWING PUMP
TRA2
TRA1
( FWD )
(REV)
TRP
TLT
(CLOSE)
PUMP CONTROL
PRESS. SWITCH
SOLENOID VALVE
ON : H MODE
OFF : L,S MODE
PUMP CONTROL
PRESS.SWITCH
Pi
R
T1
RIGHT
L'
L'
BR
BR
MB
MA
M
MB
A'
B'
STICK CYLINDER
FRONT
BOOM CYLINDERS
BUCKET CYLINDER
PR
PG
E
F
SWIVEL
SWING
D
SH
XB
MA
T1
LEFT
A'
SH
D
F
E
P
T
M2
M1
B'
B
P1
T
P2
Pi
Dr
REV
FWD
FWD
A
TRACK
T2
X
T2
P
REV
A2
PP
T
B
DR5
A
JPd
Jd
JPg
JP1
T
IN
OUT
HEAVY LIFT
SOLENOID VALVE (2)
NORMAL : OFF
HEAVY LIFT : ON
HEAVY LIFT
SOLENOID VALVE (1)
NORMAL : OFF
HEAVY LIFT : ON
(OPEN)
(UP)
JL2JL4JR4
Pi1 Pi2 Pi3
aR3
DR1
aL3
bR3
DR2
DR3
bL3
aL1
aR1
bL4
aL4
bR1
PF
PR
bL1
TOUT
PIN
PG
LS2
DR4
AL4
BR1
R2
ATT
AR1
Pi4
BL1
AL1
IMP2
PSW
PTA
TRBM1
AR3BR3
AL3
BL3
AL2
PG
PR
FRONT
BL4
bL2
A3
A4
A5
A1
S
P
B1
T
B2
B3
BM2
IMP1
T
T
P
SD1
P
aL2
R1
STICK
A
BUCKET
CLOSE
BOOM
TRAVEL(L)
TRAVEL(R)
B4
B5
Z
Y
(DOWN)(CLOSE)
(OPEN)
STICKSWING
BOOMBUCKET
TRAVEL(R)
TRAVEL(L)
M
MA
B
A
CLOSE
PD
P1
T
P2Pi
Dr
(REAR)
(FRONT)
X
PS1
LS1
S1Dr1 Dr2
LS2
OPENOPEN
BL2
PS
SA2
M2
P2
P1
M1
UPDOWN
TRAVEL ALARM
PRESS. S/W
SA1
ENGINE SPEED
SIGNAL
DS
dR1 HL1
LS
DOWN
UP
SWING 2 STEP
POWER CONTROL
MAIN CONNECTOR LINE
PILOT LINE
DRAIN LINE
Item
No.
Description
ATTACHMENT COMPONENTS
1
2
3
4
5
6
Boom Drift Reduction Valve
Solenoid Valve, Heavy Lift
Check Valve
Pressure Reducing Valve
Solenoid/Pilot Valve
Solenoid Valve, Heavy Lift
