KENR5490-01 VOL 1
30 Page (Dimensions: 39 inches x 28 inches)
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 PEDALGENERAL 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
A B
P T
A B
P T
SHIFTED POSITION
INFINITE POSITION
CONTROL VALVES
ATTACHMENT
MANUAL SHUTOFF
SHUTTLE PILOT
CONTROLLED
Hydraulic Symbols (Electrical)
Electrical Symbols Table
325-AG135 PK-14
Circuit Identification
Number
Wire Color
Wire Gauge
Harness identification code
This example indicates
wire 135 in harness "AG".
325-PK-14
Wire Gauge
Wire Color
Circuit Number
Identification
Wire Number Identification Codes
Current Standard
Previous Standard
Electrical Schematic Example
Hydraulic Schematic Example
325-PK
Wire Color
Circuit Number
Identification
B
A
Wire
Wire
(EXAMPLE VALVE)
Current Standard
Transducer
(Fluid)
Transducer
(Gas / Air)
G
Generator
Electrical Wire
Pressure Switch
M
Electric Motor
Pressure Switch
(Adjustable)
Temperature Switch
T
Pressure
Symbol
Temperature
Symbol
Level
Symbol
Flow
Symbol
Electrical Symbols (Electrical)
Volume 1 of 2: Pilot (Center Pivot)
KENR5490-01
April 2010
450E Backhoe Loader
Hydraulic System
EBL1-UP
©
2010 Caterpillar
All Rights Reserved
Printed in U.S.A.
COMPONENT LOCATIONS
3
1
6 7
6
5
5
7
3
1
8
8
9
9
9
10
10
10
11
11
11
12
12
12
14
13
13
14
15
16
15
15
14
17
16
23
232425
242528
28
29
Tap Description
T1 Pump Discharge
T2 Load Sense
SOS Oil Sampling
TAP LOCATIONS
(A) Outlet Manifold
(B) Left Stabilizer Control Valve
(C) Extendable Stick Control Valve
(D) Bucket Control Valve
(E) Swing Control Valve
(F) Stick Control Valve
(G) Boom Control Valve
A B C D E F
G
H
I
BACKHOE VALVE
29
The 450E machines are equipped with a pilot controlled backhoe valve that is visible with the floor plate at the rear
of the cab removed.
This illustration shows a eight bank backhoe valve. The components in the backhoe valve are:
SOS
Implement and
Steering Pump
HYDRAULIC OIL FILTER
SOS
Filter Bypass Switch
6
The 450E machines are equipped with a mechanically
controlled loader valve as shown in this illustration.
The loader valve is accessed from below the floor
plate. The loader control valve group contains:
LOADER VALVE
E
28
DC
B
A
Travel at high speeds over rough terrain causes bucket movement. The
optional Ride Control System acts as a shock absorber by absorbing
bucket forces, which stabilize the machine.
The Ride Control System components include; ride control relay (A), ride
control solenoids (B), ride control accumulator (C), and ride control
pressure switch (D).
Two solenoids are now used on the "E" Series machines Ride Control
System.
The Ride Control System, on machines with the optional autoshift
transmission, is controlled by the Machine ECM. The Machine ECM
monitors the position of the ride control switch and determines when to
operate the ride control system.
RIDE CONTROL
B
A
C
D
IMPLEMENT / STEERING PUMP
The implement and steering pump on the 450E machines is similar to the "D" Series
machines, but now includes a torque control solenoid (not visible). The torque control solenoid
provides an additional pump setting.
The implement and steering pump is located below the floor plate in the cab. The pump control
valve (H) contains a torque control spool adjustment screw (B) and a flow compensator adjust-
ment screw (A). The adjustment screws and the load sensing pressure tap (T2) are accessible
from the cab.
1
F
View of mechanically controlled loader valve with floor plate removed.
Loader Valve
These illustrations show the implement and steering pump out of the machine. The following compo-
nents are visible:
Torque control adjustment (A), Flow compensator adjustment (B), Load sensing pressure tap (T2),
Inlet port (C), Case drain port (D), Torque control solenoid (E), Discharge pressure tap (T1), Torque
limiter (F), Outlet port (G)
B
C
D
THREE BANK VALVE:
J
K
M
P
R
N
E
G
A
B
E
F
D
C
D
E
C
T2
T1
T2
T1
The 450E machines are equipped with hydraulically assisted master cylinders, which decreases the
amount of pedal effort when braking. This illustration shows the boosted brakes valve group, which uses
oil from the pilot accumulator to add boost to the master cylinder. The hydraulic force multiplies the pedal
effort so the operator can get more braking force with less effort.
The brake boost valves are connected to the master cylinder (A) at each brake pedal (B). Oil enters
the master cylinder through the supply hose (C) and exits the master cylinder through the return hose
(D). The oil flows to the service brakes through the hoses (E) at the bottom of the master cylinder.
The master cylinders can be removed from the machine from inside the operator's compartment.
This illustration shows a sectional view of the boosted brake valve group. When the brake pedal is
depressed, the boost brake valve moves to the left and inlet oil from the pilot manifold is directed
to the master cylinder.
BOOSTED BRAKES
J
K
Drain
EIGHT BANK VALVE (PILOT OPERATED)
For other bank valve configurations see KENR5488 (Specifications Manual).
T3
The pilot manifold can also be
accessed with the floor plate
removed. The pilot pressure tap
(T3) is located on the pilot mani-
fold. The pilot manifold routes pilot
oil to and from the loader and
backhoe pilot control valves.
Pilot Manifold
View of pilot controlled backhoe valve with floor plate removed.
The hydraulic oil filter is located below the
machine at the left frame rail. The hydraulic oil
filter bypass switch is mounted to the oil filter
base.
(H) Auxiliary Control Valve
(I) Right Stabilizer Control Valve
(J) Pilot On/Off Solenoid Valve
(K) Inlet Manifold
(L) A Ports
(M) B Ports
(N) Load Signal Relief Valve
(A) Outlet manifold.
(B) Auxiliary control valve.
(J) Makeup and relief valve.
(C) Tilt control valve.
(D) Lift control valve.
(E) Inlet manifold.
(M) Priority Valve.
(F) Load signal relief valve.
(N) Mechanical detent for the
float.
(P) A ports.
(R) B ports.
SOS
ECM
To Wheel
Brake
Boost Brake
Valve
From Pilot
Accumulator
To Tank
Master
Cylinder
Slave
Cylinder
A BE D C
T3 Pilot Pressure
23 24 25
NOTE: Alpha numeric numbers are represented by the number only on the machine views.
22
29
22
19
19
18
18
27 26
27
26
Hydraulic Oil Filter
Temp Sensor
Filter Bypass
Switch
Temp Sensor
L
M
Implement and
Steering Pump
A
B
T2
C
Loader Valve
H
ITEM NAME 450E (PILOT) 450E (MECH)
1 PUMP GP. (Primary)
269-9336
2 PUMP GP. (Secondary)
280-7873
4 TANK GROUP
245-0169
5 COOLER
N/A
6 FILTER
307-9799
7 HMU
210-6240
8 STEER CYL.
9
LIFT CYL.
10 TILT CYL.
100-7844
11 MP BUCKET CYL.(OPT)
12
STABILIZER CYLNDERS
12A LH
270-7290
12B RH
270-7291
13 BOOM CYLINDER 270-7285
14 STICK CYL. 270-7286
15 SWING CYL.
286-8903
16 BUCKET CYL.
270-7287
17 E-STICK CYL (OPT).
270-7288
VALVE GROUP (2-BANK)
18 PILOT - LEVER W/DTNT & SWTCH
223-4715
19 PILOT
267-2758
22 ACCUMULATOR
226-0420
23 RIDE CNTRL VALVE (OPT)
245-8780
24 RIDE CNTRL ACCMLTR (OPT)
162-3960
25 RIDE CNTR PRES. SWTCH (OPT)
304-5696
26 TEMP. SENSOR
246-4297
27 DIFF. PRES. SWITCH
134-0404
28
LOADER VALVE
2 BANK
271-0512
3 BANK
271-0513
28A INLET SECTION
271-0520
28B LIFT SECTION
271-0521
28C TILT SECTION
271-0522
28D AUX SECTION
271-0523
28E OUTLET MANIFOLD
269-1079
29
BACKHOE VALVE
7 BANK
271-0527
8 BANK
271-0527
29A INLET SECTION
269-1062
29B STABILIZER SECTION
271-0541
29C AUX SECTION
271-0547
29D BOOM SECTION
271-0542
29E STICK SECTION
271-0543
29F SWING SECTION
271-0544
29G BUCKET SECTION
271-0545
29H E-STICK SECTION
271-0546
29J OUTLET MANIFOLD
271-0539
29K PATTERN SWITCHING VALVE
299-9072
21 VALVE GP - CUSHION RELIEF
283-6331
30 VALVE GP - CUTOFF
260-3022
31 PRESSURE REUDCING VALVE
300-0430
20 MANIFOLD - PILOT
268-0094
226-5540
238-5285
125-7895
COMPONENT LIST
3 HYDRAULIC TANK
280-7873
271-0517
266-2558
271-0531
271-0537
271-0532
271-0533
271-0534
271-0535
271-0536
N/A
Drain
N
(K) Magnetic detent for return
to dig function.
For other bank valve configurations see KENR5488 (Specifications Manual).
4
4
Note: The auxiliary Control Valve (H) is not avalible on the optional seven bank valve.
KENR5490-01 VOL 1
30 Page, (Dimensions: 39 inches x 28 inches)
LINE PATTERNS
Drain / Return Lines
Component Group
Pilot / Load Sensing Pressure
Pressure Line
Attachment
Air Line
CALLOUTS
Taps (Pressure, Sampling,Sensor) by letter
Components by number
YY
52
DRAIN / RETURN LINE
HYDRAULIC CIRCUIT COLOR DESCRIPTIONS
IMPLEMENT and STEERING PUMP CIRCUIT
SWING CYLINDER CIRCUIT
STEERING CYLINDER CIRCUIT
PILOT OIL CIRCUIT
BUCKET CYLINDER CIRCUIT
STICK CYLINDER CIRCUIT
LOAD SENSE CIRCUIT
SUPPLY LINE
AUXILIARY CIRCUIT (BACKHOE VALVE)
E-STICK CYLINDER CIRCUIT
BOOM CYLINDER CIRCUIT
STABILIZER CYLINDER CIRCUIT
BOOSTED BRAKE OIL CIRCUIT
LIFT CYLINDER CIRCUIT
TILT CYLINDER CIRCUIT
AUXILIARY CIRCUIT (LOADER VALVE)
THIS SCHEMATIC IS FOR THE 450E BACKHOE LOADERS
PART #: 254-0098 CHG02 VOLUME 1 OF 2 (Pilot)
Components are shown installed on a fully operable machine with the key and engine off.
Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations
ITEM
VALVE
450E PILOT 450E MECHANICAL
P1 LS RELIEF LOADER SYSTEM PRESSURE 24400 kPa (2200 kPa MARGIN)
P2 LS RELIEF BACKHOE SYSTEM PRESSURE 26200 kPa (2200 kPa MARGIN)
P3 HMU LS RELIEF SYSTEM PRESSURE 18700 kPa (2200 kPa MARGIN)
P4 TILT RE 26000 kPa
P5 TILT HE 26000 kPa
P6 LOADER AUX HE 24500 kPa
P7 STABILIZER RE (THERMAL RELIEF) 29000 kPa
P8 BUCKET RE & HE 31500 kPa
P9 BOOM HE 16500 kPa
P10 BOOM RE 34000 kPa
P11 STICK HE 29000 kPa
P12 STICK RE 29000 kPa
P13 SWING RE & HE 27500 kPa
P14 E-STICK HE & RE 27500 kPa
P15 BACKHOE AUX HE & RE 27500 kPa
P16 BACK PRESSURE CHECKVALVE 379 kPa
P17 FILTER BYPASS 345 kPa
P18 COOLER BYPASS 379 kPa
P19 STEERING CYL. RELIEF 23400 kPa
P20 FLUSHING VALVE 2660 kPa @ 20 LPM
PR1 PILOT PRESSURE REDUCING 3450 kPa
R1 LS DRAIN REGULATOR 0.7 LPM
*Aux Section not avalible on the
7 Bank Valve configuration.
A
B
C
D
E
F
G
H
I
A
B
C
D
E
F
G
H
I
12 11 10 9 8 7 6 5 4 3 2 1
12 11 10 9 8 7 6 5 4 3 2 1
STAB RH BOOM STICK SWING BUCKET E-STICK STAB LH
HMU
PUMP
BACKHOE VALVE
1
4
3
26
27
5
FRONT STEER CYL.
AUX.
TILT
LIFT
LOADER VALVE
LEFT JOYSTICK RIGHT JOYSTICKSTABILIZER JOYSTICK
20
BOOSTED BRAKES (REF)
BS
BT
LEFT
BRAKE
PEDAL
RIGHT
BRAKE
PEDAL
TO REAR AXLE
LEFT WHEEL BRAKE
TO REAR AXLE
RIGHT WHEEL BRAKE
DEL
28
T3
T2
T1
12B
13
14
15
21
16
17
12A
29J29B
29H
29G
29F
29K
29D29B29A
22
29
28A
28B
28C
28D
11
10
9
25
24
23
18
19
29E
SOS
7
8
28E
2
AUX.
6
P16
P17
P18
30
*29C
31
P2
P1
P20
P7
P14
P8
P13
P11
P12
P10
P9
P15
P7
PR1
P19
P3
P6
P5
P4
P1
KENR5490-01 VOL 2
30 Page (Dimensions: 39 inches x 28 inches)
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 PEDALGENERAL 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
A B
P T
A B
P T
SHIFTED POSITION
INFINITE POSITION
CONTROL VALVES
ATTACHMENT
MANUAL SHUTOFF
SHUTTLE PILOT
CONTROLLED
Hydraulic Symbols (Electrical)
Electrical Symbols Table
325-AG135 PK-14
Circuit Identification
Number
Wire Color
Wire Gauge
Harness identification code
This example indicates
wire 135 in harness "AG".
325-PK-14
Wire Gauge
Wire Color
Circuit Number
Identification
Wire Number Identification Codes
Current Standard
Previous Standard
Electrical Schematic Example
Hydraulic Schematic Example
325-PK
Wire Color
Circuit Number
Identification
B
A
Wire
Wire
(EXAMPLE VALVE)
Current Standard
Transducer
(Fluid)
Transducer
(Gas / Air)
G
Generator
Electrical Wire
Pressure Switch
M
Electric Motor
Pressure Switch
(Adjustable)
Temperature Switch
T
Pressure
Symbol
Temperature
Symbol
Level
Symbol
Flow
Symbol
Electrical Symbols (Electrical)
Volume 2 of 2: Mechanical (Center Pivot)
KENR5490-01
April 2010
450E Backhoe Loader
Hydraulic System
EBL1-UP
©
2010 Caterpillar
All Rights Reserved
Printed in U.S.A.
Note: The auxiliary Control Valve (C) is not avalible on the optional seven bank valve.
ITEM NAME 450E (PILOT) 450E (MECH)
1 PUMP GP. (Primary)
269-9336
2 PUMP GP. (Secondary)
280-7873
4 TANK GROUP
245-0169
5 COOLER
N/A
6 FILTER
307-9799
7 HMU
210-6240
8 STEER CYL.
9
LIFT CYL.
10 TILT CYL.
100-7844
11 MP BUCKET CYL.(OPT)
12
STABILIZER CYLNDERS
12A LH
270-7290
12B RH
270-7291
13 BOOM CYLINDER 270-7285
14 STICK CYL. 270-7286
15 SWING CYL.
286-8903
16 BUCKET CYL.
270-7287
17 E-STICK CYL (OPT).
270-7288
VALVE GROUP (2-BANK)
18 PILOT - LEVER W/DTNT & SWTCH
223-4715
19 PILOT
267-2758
22 ACCUMULATOR
226-0420
23 RIDE CNTRL VALVE (OPT)
245-8780
24 RIDE CNTRL ACCMLTR (OPT)
162-3960
25 RIDE CNTR PRES. SWTCH (OPT)
304-5696
26 TEMP. SENSOR
246-4297
27 DIFF. PRES. SWITCH
134-0404
28
LOADER VALVE
2 BANK
271-0512
3 BANK
271-0513
28A INLET SECTION
271-0520
28B LIFT SECTION
271-0521
28C TILT SECTION
271-0522
28D AUX SECTION
271-0523
28E OUTLET MANIFOLD
269-1079
29
BACKHOE VALVE
7 BANK
271-0527
8 BANK
271-0527
29A INLET SECTION
269-1062
29B STABILIZER SECTION
271-0541
29C AUX SECTION
271-0547
29D BOOM SECTION
271-0542
29E STICK SECTION
271-0543
29F SWING SECTION
271-0544
29G BUCKET SECTION
271-0545
29H E-STICK SECTION
271-0546
29J OUTLET MANIFOLD
271-0539
29K PATTERN SWITCHING VALVE
299-9072
21 VALVE GP - CUSHION RELIEF
283-6331
30 VALVE GP - CUTOFF
260-3022
31 PRESSURE REUDCING VALVE
300-0430
20 MANIFOLD - PILOT
268-0094
226-5540
238-5285
125-7895
COMPONENT LIST
3 HYDRAULIC TANK
280-7873
271-0517
266-2558
271-0531
271-0537
271-0532
271-0533
271-0534
271-0535
271-0536
N/A
COMPONENT LOCATIONS
Tap Description
T1 Pump Discharge
T2 Load Sense
SOS Oil Sampling
TAP LOCATIONS
BACKHOE VALVE
29
SOS
Implement and
Steering Pump
HYDRAULIC OIL FILTER
SOS
Filter Bypass Switch
6
LOADER VALVE
28
Travel at high speeds over rough terrain causes bucket movement. The
optional Ride Control System acts as a shock absorber by absorbing
bucket forces, which stabilize the machine.
The Ride Control System components include; ride control relay (A), ride
control solenoids (B), ride control accumulator (C), and ride control
pressure switch (D).
Two solenoids are now used on the "E" Series machines Ride Control
System.
The Ride Control System, on machines with the optional autoshift
transmission, is controlled by the Machine ECM. The Machine ECM
monitors the position of the ride control switch and determines when to
operate the ride control system.
RIDE CONTROL
B
A
C
D
IMPLEMENT / STEERING PUMP
1
View of mechanically controlled loader valve with floor plate removed.
Loader Valve
These illustrations show the implement and steering pump out of the machine. The following components
are visible:
Torque control adjustment (A), Flow compensator adjustment (B), Load sensing pressure tap (T2), Inlet
port (C), Case drain port (D), Torque control solenoid (E), Discharge pressure tap (T1), Torque limiter
(F), Outlet port (G)
B
C
D
E
G
A
B
E
F
D
C
D
E
C
T2
T1
T2
T1
The 450E machines are equipped with hydraulically assisted master cylinders, which decreases the
amount of pedal effort when braking. This illustration shows the boosted brakes valve group, which uses
oil from the pilot accumulator to add boost to the master cylinder. The hydraulic force multiplies the pedal
effort so the operator can get more braking force with less effort.
The brake boost valves are connected to the master cylinder (A) at each brake pedal (B). Oil enters
the master cylinder through the supply hose (C) and exits the master cylinder through the return hose
(D). The oil flows to the service brakes through the hoses (E) at the bottom of the master cylinder.
The master cylinders can be removed from the machine from inside the operator's compartment.
This illustration shows a sectional view of the boosted brake valve group. When the brake pedal is
depressed, the boost brake valve moves to the left and inlet oil from the pilot manifold is directed
to the master cylinder.
BOOSTED BRAKES
Drain
For other bank valve configurations see KENR5488 (Specifications Manual).
T3
The pilot manifold can also be
accessed with the floor plate
removed. The pilot pressure tap
(T3) is located on the pilot mani-
fold. The pilot manifold routes pilot
oil to and from the loader and
backhoe pilot control valves.
Pilot Manifold
View of pilot controlled backhoe valve with floor plate removed.
The hydraulic oil filter is located below the
machine at the left frame rail. The hydraulic oil
filter bypass switch is mounted to the oil filter
base.
SOS
ECM
To Wheel
Brake
Boost Brake
Valve
From Pilot
Accumulator
To Tank
Master
Cylinder
Slave
Cylinder
A BE D C
T3 Pilot Pressure
23 24 25
NOTE: Alpha numeric numbers are represented by the number only on the machine views.
Hydraulic Oil Filter
Temp Sensor
Filter Bypass
Switch
Temp Sensor
(A) Outlet Manifold
(B) Left Stabilizer Control Valve
(C) Auxiliary Control Valve
(D) Extendable Stick Control Valve
(E) Bucket Control Valve
(F) Swing Control Valve
(G) Stick Control Valve
A B CD E F
G
H
I
The 450E machines are equipped with a pilot controlled backhoe valve that is visible with the floor plate at the
rear of the cab removed. This illustration shows a eight bank backhoe valve in the 450E Backhoe Loader. The
components in the backhoe valve are:
J
K
EIGHT BANK VALVE (MECHANICALLY OPERATED)
(H) Boom Control Valve
(I) Right Stabilizer Control Valve
(J) Pilot On/Off Solenoid Valve
(K) Inlet Manifold
(L) A Ports
(M) B Ports
(N) Load Signal Relief Valve
L
M
The implement and steering pump on the 420E and 430E machines is similar to the "D"
Series machines, but now includes a torque control solenoid (not visible). The torque
control solenoid provides an additional pump setting.
The implement and steering pump is located below the floor plate in the cab. The pump
control valve (H) contains a torque control spool adjustment screw (B) and a flow compen-
sator adjustment screw (A). The adjustment screws and the load sensing pressure tap (T2)
are accessible from the cab.
Implement and
Steering Pump
A
B
T2
C
Loader Valve
H
Drain
3
1
6 7
6
5
5
7
3
1
8
8
9
9
9
10
10
10
11
11
11
12
12
12
14
13
13
14
15
16
15
15
14
17
16
23
232425
242528
28
29
The 450E machines are equipped with a mechanically
controlled loader valve as shown in this illustration.
The loader valve is accessed from below the floor
plate. The loader control valve group contains:
E
DC
B
A
F
THREE BANK VALVE:
J
K
M
P
R
N
(A) Outlet manifold.
(B) Auxiliary control valve.
(J) Makeup and relief valve.
(C) Tilt control valve.
(D) Lift control valve.
(E) Inlet manifold.
(M) Priority Valve.
(F) Load signal relief v
alve.
(N) Mechanical detent for the
float.
(P) A ports.
(R) B ports.
22
29
22
19
19
18
18
27 26
27
26
(K) Magnetic detent for return
to dig function.
For other bank valve configurations see KENR5488 (Specifications Manual).
4
4
N
KENR5490-01 VOL 2
30 Page, (Dimensions: 39 inches x 28 inches)
LINE PATTERNS
Drain / Return Lines
Component Group
Pilot / Load Sensing Pressure
Pressure Line
Attachment
Air Line
CALLOUTS
Taps (Pressure, Sampling,Sensor) by letter
Components by number
YY
52
DRAIN / RETURN LINE
HYDRAULIC CIRCUIT COLOR DESCRIPTIONS
IMPLEMENT and STEERING PUMP CIRCUIT
SWING CYLINDER CIRCUIT
STEERING CYLINDER CIRCUIT
PILOT OIL CIRCUIT
BUCKET CYLINDER CIRCUIT
STICK CYLINDER CIRCUIT
LOAD SENSE CIRCUIT
SUPPLY LINE
AUXILIARY CIRCUIT (BACKHOE VALVE)
E-STICK CYLINDER CIRCUIT
BOOM CYLINDER CIRCUIT
STABILIZER CYLINDER CIRCUIT
BOOSTED BRAKE OIL CIRCUIT
LIFT CYLINDER CIRCUIT
TILT CYLINDER CIRCUIT
AUXILIARY CIRCUIT (LOADER VALVE)
THIS SCHEMATIC IS FOR THE 450E BACKHOE LOADERS
PART #: 254-0098 CHG02 VOLUME 2 OF 2 (MECHANICAL)
Components are shown installed on a fully operable machine with the key and engine off.
Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations
ITEM
VALVE
450E PILOT 450E MECHANICAL
P1 LS RELIEF LOADER SYSTEM PRESSURE 24400 kPa (2200 kPa MARGIN)
P2 LS RELIEF BACKHOE SYSTEM PRESSURE 26200 kPa (2200 kPa MARGIN)
P3 HMU LS RELIEF SYSTEM PRESSURE 18700 kPa (2200 kPa MARGIN)
P4 TILT RE 26000 kPa
P5 TILT HE 26000 kPa
P6 LOADER AUX HE 24500 kPa
P7 STABILIZER RE (THERMAL RELIEF) 29000 kPa
P8 BUCKET RE & HE 31500 kPa
P9 BOOM HE 16500 kPa
P10 BOOM RE 34000 kPa
P11 STICK HE 29000 kPa
P12 STICK RE 29000 kPa
P13 SWING RE & HE 27500 kPa
P14 E-STICK HE & RE 27500 kPa
P15 BACKHOE AUX HE & RE 27500 kPa
P16 BACK PRESSURE CHECKVALVE 379 kPa
P17 FILTER BYPASS 345 kPa
P18 COOLER BYPASS 379 kPa
P19 STEERING CYL. RELIEF 23400 kPa
P20 FLUSHING VALVE 2660 kPa @ 20 LPM
PR1 PILOT PRESSURE REDUCING 3450 kPa
R1 LS DRAIN REGULATOR 0.7 LPM
A
B
C
D
E
F
G
H
I
A
B
C
D
E
F
G
H
I
12 11 10 9 8 7 6 5 4 3 2 1
12 11 10 9 8 7 6 5 4 3 2 1
STAB RH BOOM
STICK
SWING
BUCKET E-STICK STAB LH
HMU
PUMP
BACKHOE VALVE
1
4
3
6
26
27
5
FRONT STEER CYL.
AUX.
TILT
LIFT
LOADER VALVE
STABILIZER JOYSTICK
20
BOOSTED BRAKES (REF)
BS
BT
LEFT
BRAKE
PEDAL
RIGHT
BRAKE
PEDAL
TO REAR AXLE
LEFT WHEEL BRAKE
TO REAR AXLE
RIGHT WHEEL BRAKE
DEL
28
T3
T2
T1
12B
13
14
15
21
16
17
12A
29J29B
29H
29G
29F29D29B29A
22
29
28A
28B
28C
28D
11
109
25
24
23
18
SOS
7
8
28E
2
AUX.
P17
P18
P16
3029E*29C
31
P2
R1
P20
P7
P14
P8
P13
P11
P12
P10
P9
P15
P7
PR1
P1
P5 P4
P6
P3
P19
*Aux Section not avalible on the
7 Bank Valve configuration.
