©
2005] Caterpillar
All Rights Reserved
Printed in U.S.A.
RENR5425-02
January 2005
385B Excavators
Fine Filtration
MYA1-UP
RCD1-UP
FDL1-UP
ANS1-UP
CLS1-UP
Hydraulic System (Attachment)
ONE POSITION
TWO POSITION
THREE POSITION
VENTED
PRESSURIZED
RETURN ABOVE FLUID LEVEL
RETURN BELOW FLUID LEVEL
LINES CROSSING
LINES JOINING
TWO-WAY
THREE-WAY
FOUR-WAY
SPRING
CONTROL VALVES
RESTRICTION
LINE RESTRICTION
(FIXED)
2-SECTION PUMP
MAIN
AUX.
SPRING
(ADJUSTABLE)
VARIABILITY
LINE RESTRICTION
(VARIABLE)
LINE RESTRICTION
(VARIABLE and PRESSURE COMPENSATED)
PRESSURE
COMPENSATION
PUMP: VARIABLE and
PRESSURE COMPENSATED
ENERGY TRIANGLES
HYDRAULIC PNEUMATIC
MEASUREMENT
PRESSURE
TEMPERATURE
FLOW
ROTATING SHAFTS
UNIDIRECTIONAL BIDIRECTIONAL
PUSH-PULL LEVER
PEDAL
GENERAL MANUAL
PUSH BUTTON
SPRING
MANUAL CONTROL SYMBOLS
HYDRAULIC MOTORS
FIXED
DISPLACEMENT
VARIABLE DISPLACEMENT
NON-COMPENSATED
UNIDIRECTIONAL
BIDIRECTIONAL
HYDRAULIC PUMPS
FLUID STORAGE RESERVOIRS
CROSSING AND JOINING LINES
VALVE ENVELOPES
VALVE PORTS
BASIC COMPONENT SYMBOLS
FLUID CONDITIONER
PUMP or MOTOR
FLUID POWER SYMBOLS
FIXED
DISPLACEMENT
VARIABLE DISPLACEMENT
NON-COMPENSATED
UNIDIRECTIONAL
BIDIRECTIONAL
VALVES
PILOT CONTROL SYMBOLS
RELEASED PRESSURE
EXTERNAL RETURN
INTERNAL RETURN
REMOTE SUPPLY PRESSURE
SIMPLIFIED
COMPLETE
INTERNAL
SUPPLY PRESSURE
ACCUMULATORS
SPRING LOADED
GAS CHARGED
SOLENOID
or MANUAL
SOLENOID
and PILOT
SOLENOID and
PILOT or MANUAL
COMBINATION CONTROLS
SOLENOID
SERVO
THERMAL
DETENT
HYDRAULIC AND PNEUMATIC CYLINDERS
DOUBLE ACTING
SINGLE ACTING
BASIC SYMBOL
SPRING LOADED
CHECK VALVES
TWO
POSITION
INFINITE
POSITIONING
FLOW IN ONE
DIRECTION
FLOW ALLOWED IN
EITHER DIRECTION
THREE
POSITION
CROSS
FLOW
PARALLEL
FLOW
INTERNAL PASSAGEWAYS
NORMAL POSITION
AB
PT
AB
PT
SHIFTED POSITION
INFINITE POSITION
CONTROL VALVES
385B:
5090B:
SJY1-UP
Schematic
RIGHT
C
STICK CYLINDER BOOM CYLINDERBUCKET CYLINDER
PRPB
E
F
SWING
PR
A
Dr
B
Dr
Pi
Pi
Pa
Pb
L2
D
L1
Qmax Qmin
LEFT
D
F
E
P1
P2
Dr
REV
FWD FWD
TRACK
REV
BL2
AL2
PSA3
PSA2
PSA1
PG
PIN
TOUT
DR1
DR2
DR3
Pi5
PAC
Pi3
Pi2
Pi1
Pi4
Pi6
M1
T2T1
R
S
A
PSA4
DR6
M
G
aR3
aL3
bR3
bL3
aL1
aR1
bL4
aL4
bR1
PF
PR
bL1
D1
D2
AL4
BR1
R2
ATT
AR1
BL1
AL1
AR3
BR3
AL3
BL3
PSga2a1
DR5
BL4
A
B
dR1
bL2
LS2
B
L1
PS1
B
A
L
aL2
R1
STICK
BUCKET
UP
S
BOOM
TRAVEL
(L)
TRAVEL
(R)
DR4
LS1
SA1
P2
Pb
Pa
Pi
Pi
Dr
P1
)(
)(
C
FRONT
P
T
B
M2
Dr
A
CLOSE
P1
P2
M1
Dr
REAR
B
PR
B1
DOWN
OPEN
A
NN
SA2
OUT
IN
MAIN CONNNECTOR LINE
PILOT LINE
DRAIN LINE
This Attachment Schematic is intended to
be used in conjunction with the Standard
Hydraulic Schematic in this Service Manual.
Hydraulic Schematic
201-4925
P
P
1
1
Item
Component
No.
ATTACHMENT COMPONENTS
1
Hydraulic Oil Filter
f05349
