©
2003 Caterpillar
All Rights Reserved
Printed in U.S.A.
This attachment schematic is to be used in conjunction with the Standard Schematic in
this Service Manual.
RENR5419-02
February 2003
385B Excavators
One Way with Two Pump Flow
MYA1-UP
RCD1-UP
BKF1-UP
FDL1-UP
CLS1-UP
BKX1-UP
BLY1-UP
Hydraulic System - Attachment
RIGHT
C
STICK CYLINDER BOOM CYLINDERBUCKET CYLINDER
PR
PB
E
F
SWING
PR
A
Dr
B
Dr
Pi
Pi
Pa
Pb
L2
D
L1
Qmax Qmin
LEFT
D
F
E
P2
Dr
TRACK
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
aL3
bL3
D1
D2
AL4
BR1
R2
ATT
AR1
BL1
AL1
AR3AL3
PSga2a1
DR5
BL4
A
B
bL2
SINGLE SINGLE
PF
PR
LS2
B
L1
PS1
B
A
L
R1
STICK
1
BUCKET
S
BOOM
TRAVEL
(L)
TRAVEL
(R)
DR4
LS1
REV
SA1
P2
Pb
Pa
Pi
Pi
Dr
P1
)(
)(
C
FWD FWD
REV
aL1
aR1
bL4
aL4
bR1
bL1
OUT
IN
P1
aR3
aL3
bR3bL3
BR3
FRONT
P
T
B
M2
Dr
A
BL3
P1
P2
M1
aL2
UP
Dr
REAR
B
CLOSE
DOWN
PR
B1
OPEN
A
NN
SA2
OUT
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
177-2650
P
P
1 2
1
2
Item
Component
No.
ATTACHMENT COMPONENTS
1
2
1
2
Line Relief Valve (One Way Flow)
Proportional Valve (Attachment)
The attachment proportional valve is
controlled by the attachment control pedal.
f05395
