1. RENR6482-02
24Page,(Dimensions:34inchesx28inches)
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 ColorCircuit Number
Identification
B A
Wire
Wire
(EXAMPLE VALVE)
Current Standard
Transducer
(Fluid)
Transducer
(Gas / Air)
G
Generator
Electrical WirePressure Switch
M
Electric Motor
Pressure Switch
(Adjustable)
Temperature Switch
Pressure
Symbol
Temperature
Symbol
Level
Symbol
Flow
Symbol
Electrical Symbols (Electrical)
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 CONDITIONERPUMP 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 ACTINGSINGLE 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
T
RENR6482-02
October 2007
416E, 422E and 428E Backhoe Loader
Hydraulic System
416E:
SHA1-UP
CBD1-UP
422E:
HBE1-UP
428E:
SNL1-UP
©2007 Caterpillar
All Rights Reserved
Printed in U.S.A.
416E (Single Tilt Center Pivot)
422E (Single Tilt Sideshift)
428E (Parallel Lift Sideshift)
23
(A) Extendable Stick Control Valve
(B) Stick Control Valve
(C) Bucket Control Valve
(D) Swing Control Valve
(E) Boom Control Valve
(F) Auxiliary Control Valve
(G) Middle Inlet Manifold
(H) Left Stabilizer Control Valve
(J) Right Stabilizer Control Valve
(K) Solenoid for the Sideshift Lock
K
A B C D E F G
H J
BACKHOE VALVE 21 22
The 416E, 422E and 428E
machines are equipped with a
mechanically controlled backhoe
valve that is visible with the floor
plate at the rear of the cab
removed.
IMPLEMENT / STEERING PUMP
The implement and steering pump on
the 416E/422E/428E machines is a
similar design and operates the same as
the pump on the "A" Series machines.
The pump is located below the cab floor
plate. The pump control valve is
mounted on top of the pump and
contains a flow compensator spool and
pressure cutoff spool. The implement
and steering pump supplies oil flow to
the loader valve group, backhoe valve
group, and steering system.
These illustrations show the implement and steering pump out
of the machine. The following components are visible:
Pressure Cutoff (A), Flow compensator (B), Load sensing
pressure tap (T2), Discharge pressure tap (T1), Inlet port (C),
Case drain port (D), Hydraulic Oil Tank (E), Outlet port (F)
A
A
T2T2
T1
T2
SOS
T1
B
F
C
B
D
E
C
DF
Implement and Steering Pump
1
COMPONENT LOCATIONS
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.
RIDE CONTROL 16
B
A
C
D
SOS
Implement and
Steering Pump
HYDRAULIC OIL FILTER
SOS Pressure Switch
4
The 416E/422E and 428E machines are
equipped with a mechanically controlled
loader valve (A). The loader valve is
accessed from below the floor plate.
The loader control valve group contains an
inlet manifold (B), lift control valve (C), tilt
control valve (D), and auxiliary control valve
(E, if equipped).
LOADER VALVE
E
19 20
D
C
B
A
21
4 5
4
3
3
5
2
1
6
6
7
7
7
8
8
8
9
9
9
10
10
10
12
11
111214
14
13
13
13
15
15
16
161718 1718
171819
19
20
20
22
22
21
21
23
Tap Description
T1 Pump Discharge
T2 Load Sense
SOS Oil Sampling
TAP LOCATIONS
NOTE: Alpha numeric numbers are represented by the number only on the machine views.
TILT CYL
ITEM NAME 416E 422E 428E
1 PUMP GP - PISTON 247-7867
2 TANK GP - MTG 245-8777
3 COOLER 214-2202
4 FILTER 210-6243
5 PUMP GP - METERING 247-7868
6 FRONT STEER CYL. 214-5097
7A LIFT CYL. ST 228-3508 215-7298 N/A
7B LIFT CYL. PL/IT N/A 214-9373
8A TILT CYL. ST 206-3553 N/A
8B TILT CYL. PL/IT N/A 192-3884
9 MP BUCKET CYL. 185-1839
10A STABILIZER CYL. RH 262-7050
173-4565
10B STABILIZER CYL. LH 262-7049
11 BOOM CYLINDER 246-9885(S)
210-7074 210-7074
12 STICK CYL. 210-7077(S)
210-7078 210-7080
13A SWING CYL. RH
228-3506
228-3507
13B SWING CYL. LH 228-3506
14 BUCKET CYL.
210-7085(S)
210-7086 210-7086
15 E-STICK CYL.
210-7097(S)
210-7098 210-7098
16 RIDE CONTROL VALVE 245-8780
17 RIDE CONTROL ACCMLTR 162-3960
18 PRESSURE SWITCH 131-9203
19
LOADER VALVE (ST) 2-BANK 248-0481 N/A
LOADER VALVE (ST) 3-BANK 248-0482 N/A
19A LOADER INLET 259-6745 N/A
19B LIFT VALVE 259-6732
19C TILT VALVE
259-6731 (2-BANK)
259-6730 (3-BANK)
N/A
19D AUX. VALVE 259-6729
20
LOADER VALVE (PL/IT) 2-BANK N/A 247-9655
LOADER VALVE (PL/IT) 3-BANK N/A 247-9656
20A LOADER INLET N/A 259-6743
20C TILT VALVE N/A 259-6740 (2-BANK)
259-6741 (3-BANK)
21
BACKHOE VALVE (CP) 6-BANK 248-0483 N/A
BACKHOE VALVE (CP) 7-BANK 248-0484 N/A
BACKHOE VALVE (CP) 8-BANK 248-0485 N/A
21A STABILIZER VALVE 259-6746
21B INLET MANIFOLD 259-6742 N/A
21C AUX. VALVE 259-6733
21D BOOM VALVE 259-6739
21E SWING VALVE 259-6738
21F BUCKET VALVE 259-6737
21G STICK VALVE 259-6736 (6-BANK) / 259-6735 (7 & 8-BANK)
21H E-STICK VALVE 259-6734
22
BACKHOE VALVE (SS) 6-BANK N/A 248-0486
BACKHOE VALVE (SS) 7-BANK N/A 248-0487
BACKHOE VALVE (SS) 8-BANK N/A 248-0488
22B INLET MANIFOLD N/A 259-6744
23 VALVE AS - SHUTTLE 8J-6875
COMPONENT TABLE
LOADER VALVE
BACKHOE VALVE
LOADER VALVE
BACKHOE VALVE
SWING CYL
STABILIZER CYL
LIFT CYL
7
8
10
13
19
20
21
22
Hydraulic Oil Filter
Hydraulic Oil Filter
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.

2. RENR6482-02
24Page,Color2,(Dimensions:34inchesx28inches)
DRAIN / RETURN LINE
HYDRAULIC CIRCUIT COLOR DESCRIPTIONS
IMPLEMENT and STEERING PUMP
STEERING CIRCUIT
PILOT PUMP OUTPUT
STICK CYLINDER
E-STICK CYLINDER
LOAD SENSE
SUPPLY LINE
AUX. VALVE
LOADER and BACKHOE LOAD SENSE RELIEF
BOOM CYLINDER
SWING CYLINDER
STABILIZER (STAB) LEFT and RIGHT
SIDESHIFT CYLINDERS
BUCKET CYLINDER
LIFT CYLINDERS
TILT CYLINDERS
MP BUCKET CYLINDERS
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
345678 34567 12
A
B
C
D
E
F
A
B
C
D
E
F
12345678 12345678
A
B
A
B
C
D
E
F
C
D
E
F
THIS SCHEMATIC IS FOR THE 416E, 422E AND 428E SERIES BACKHOE LOADERS
416E (SINGLE TILT CENTER PIVOT)
422E (SINGLE TITLE SIDESHIFT)
428E (PARALLEL LIFT SIDESHIFT)
PART #: 225-6836 CHG 01
Components are shown installed on a fully operable machine with the key and engine off and
transmission shifter in neutral.
Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations.
STAB-RH STAB-LH
AUX. BOOM SWING BUCKET STICK E-STICK
AUX.
TILT
LIFT
428E PL/IT
422E,428E
SIDESHIFT
19A
19B
19C
19D
5
6
4
3
2
1
T2T1
21C 21D 21E 21F 21G 21H
416E
21B
22B
21A
23
18
16
17
7A
8A
8B
9
10A 10B
11
13A 13B 14 12 15
21
A
B
C
D
E
F
G
HJK
R
P
N
M
L
A
B
C
D
E
F
G
HJK
R
P
N
M
L
19 20
20A
20C
22
SOS
7B or