5-24
GTH-1256
Part No. 1272856
September 2016
Section 5 • Schematics
Hydraulic Schematic - Perkins Engine
Perkins engine - Sheet 2 of 2
M
R
F
P
B
N’
R1
T1
T1’
T2’
T2
R2
capacity:
0.13 USG
precharge
pressure
725 psi
capacity:
0.13 USG
precharge
pressure
435 psi
Pressure
switch
activating
pressure
1,015 psi
Pressure
switch
activating
pressure
29-145 psi
(optional)
2,175 psi
A3
A1
A2
B3
B1
B2
4,350
psi
4,060
psi
5,655
psi
3,335
psi
3,625
psi
3,190
psi
2,610 psi
3,190
psi
A
B
T
T
b
b
b
a
a
a
24
GPM
42
GPM
42
GPM
13
GPM
33
GPM
33
GPM
LS
P
DLS
M
LS
LD
T
T
D
P
T
X
Y
C1
C1
C2
C2
C3
C3
C4
C4
P1
P1
P2
P2
P
T
L
R
P
T
A
B
T
A
A
B
B
V
L
P
Double displacement
steering actuator
max displacement 13.43 ci/rev
min displacement 3.66 ci/rev
A u x i l i a r y g e a r p u m p
with integrated relief valve
for brakes/chassis levelling
displacement: 1.53 ci/rev
Suction screen
Suction screen
Boom and steering
functions piston pump
load sensing type
displacement: 3.66 ci/rev
Shutoff valve
Shutoff valve
Air bleeding valve
Diesel engine
Hydraulically powered
service brakes
pedal pump
Chassis sway and boom auxiliary
line main valve
Chassis sway and
boom auxiliary line
circuit test port
Boom functions load sensing
control valve hydraulically actuated
Boom lift cylinder
Boom telescope cylinder
Forks tilt cylinder
Forks level slave cylinder
Boom functions control
hydraulically piloting joistick
Boom telescoping/chassis sway
functions selector valve
electrically actuated
Boom lift/forks tilt
functions selector valve
electrically actuated
Steering modes selector valve
electrically actuated
Hydraulic fluid
tank (capacity: 53 USG)
Rear axle
Front axle
Front axle
steering cylinder
Rear axle steering cylinder
Chassis sway cylinder
Chassis sway cylinder
1
2
3
4
N
S
L
L
1
B
X
Boom and steering functions
hydraulic circuit test port
Pump stand-by
pressure test port
(320 psi)
Hydraulically piloted
double check valve
piloting ratio: 4/1
Sing
piloting ratio: 4/1
cracking pressure: 5,075 psi
le overcenter safety valve
Double overcenter safety valve
piloting ratio: 4/1
cracking pressure: 5,075 psi
Double overcenter safety valve
piloting ratio: 7.6/1
cracking pressure: 5,075 psi
Anticavitation valve
cracking pressure
72 psi
Double overcenter safety valve
piloting ratio: 4/1
cracking pressure: 5,075 psi
X
1
X
2
G
MH
S
A
T
1
P
S
F
a
F
a1
F
e
M
B
T
2
R
B
M
A
F
S
Hydrostatic transmission pump
max displacement: 5.49 ci/rev
Check valve
cracking pressure
36 psi
Cracking pressure
6,890 psi
Cracking pressure
6,890 psi
Cracking press.
406 psi
Cracking press.
6,450 psi
Hydrostatic transmission
high pressure test port
X7
X8
TP
3
TP
4
TP
1
TP
5
TP
2
Hydrostatic transmission
boost pressure test port
Hydrostatic transmission
pump
displacement: 1.20 ci/rev
charge
Rear axle
lockout cylinder
Rear axle
lockout valve
X1
19
X120
C2
C1
P
T1
Hydrostatic transmission motor
max displacement: 6.53 ci/rev
T
P
A
B
X140
X137
A
M1
T2
G
B
U
Flushing valve
Mechanical gear speed
selector valve
4 ways/2 positions
Mechanical gear speed
selector actuator
Mechanical gearbox
(2 speeds shift-on-fly)
HYDRAULIC CIRCUIT
COLORS LEGENDA
Actuators functions lines
Low pressure lines
Hydrostatic transmission
high pressure lines
Hydraulic pi LS lines
Open circuits pressure lines
Suction lines
Tank lines
Check valve
cracking pressure:
116 psi
X122
Heat exchanger
Return filter
with suction line
pressurized at 7 psi
FRONT
RIGHT
Parking brake
selector valve
Parking brake control valve
(restrictor dia. 0.079 inches)
1
1
2
2
3
3
C2
C4
P1
P2
Boom auxiliary line/attachments quick coupling cylinder
functions selector valve electrically actuated (optional)
Quick coupling
hydraulic ports
Hydraulically piloted
double check valve
piloting ratio: 4/1
(optional)
Quick coupling cylinder
(optional)
A
B
L
X230
1,740 psi
Heat exchanger fan
hydraulic motor
displacement
0.68 ci/rev
Front axle differential
lock selector valve
(optional)
4,350
psi
X138
X136
X220
X211
X210
X141
X132
X133
X212
X200
X221
X128
C2
C4
P1
P2
X213
Chassis sway function
enabling selector valve
electrically actuated
C1
C3
C3
C1
R
Z
Shutoff valve
B2
A2
B1
A1
T
P
1
1
0
0
2
2
Outriggers control valve
X22
X21
X23
X24
4
V2
V2
V1
V1
M1
M1
M2
M2
1
1
2
2
3
3
4
C1
C1
C2
C2
RH outrigger cylinder
LH outrigger cylinder
Pressure sensitive regenerative
dual counterbalance safety valve
piloting ratio: 4.1/1
cracking pressure: 5,075 psi
Pressure sensitive regenerative
dual counterbalance safety valve
piloting ratio: 4.1/1
cracking pressure: 5,075 psi
Oil radiator
fan drive pump
displacement:
0.98 ci/rev
