8/18/2019 Cat 450E Backhole Loader Hydraulic System

1/4

   K

   E   N   R   5   4   9   0 -   0

   1   V   O   L   1

   3   0   P  a  g  e   (   D   i  m  e  n  s   i  o  n  s  :   3   9   i  n  c   h  e  s  x   2   8   i  n  c   h  e  s   )

ONEPOSITION TWO POSITION THREEPOSITION

V ENT ED P RE SS URI ZE D RETURNABOVEFLUIDLEVEL RETURNBELOWFLUIDLEVEL

LINESCROSSING LINESJOINING

TWO-WAY THREE-WAY FOUR-WAY

SPRING CONTROLVALVES RESTRICTION LINERESTRICTION

(FIXED)

2-SECTIONPUMP

MAINAUX.

SPRING

(ADJUSTABLE)

VARIABILITY LINERESTRICTION

(VARIABLE)

LINERESTRICTIONVARIABLEand PRESSURE

COMPENSATED

PRESSURE

COMPENSATION

PUMP: VARIABLEandPRESSURECOMPENS ATED

ENERGYTRIAN GLES

HY DRA ULIC P NE UMA TIC

MEASUREMENT

PRESSURE TEMPERATURE FLOW

ROTATING SHAFTS

UNIDIRECTIONAL BIDIRECTIONAL

PUSH-PULL LEVER PEDALGENERAL MANUAL PUSH BUTTON SPRING

MANUAL CONTROL SYMBOLS

HYDRAULICMOTORS

FIXED

DISPLACEMENT

VARIABLEDISPLACEMENT

NON-COMPENSATED

UNIDIRECTIONAL

BIDIRECTIONAL

HYDRAULICPUMPS

FLUIDSTORAGE RESERVOIRS

CROSSING ANDJOINING LINES

VALVE ENVELOPES VALVE PORTS

BASICCOMPONENT SYMBOLS

FLUIDCONDITIONERPUMPor MOTOR

FLUID POWER SYMBOLS

FIXED

DISPLACEMENT

VARIABLEDISPLACEMENT

NON-COMPENSATED

UNIDIRECTIONAL

BIDIRECTIONAL

VALVES

PILOT CONTROL SYMBOLSRELEASEDPRESSURE

EXTERNALRETURN INTERNALRETURN

REMOTESUPPLYPRESSUR E

SIMPLIFIED COMPLETE INTERNAL

SUPPLYPRESSURE

 ACCUMULATORS

SPRING LOADED GASCHARGED

SOLENOIDor MANUAL

SOLENOIDand PILOT

SOLENOIDandPILOTor MANUAL

COMBINATIONCONTROLS

SOLENOID SERVO THERMAL DETENT

HYDRAULICANDPNEUMATICCYLINDERS

DOUBLEACTINGSINGLEACTING

BASICSYMBOL

SPRINGLOADED

CHECK VALVES

TWO

POSITIONINFINITE

POSITIONING

FLOWINONEDIRECTION

FLOWALLOWEDINEITHERDIRECTION

THREE

POSITION

CROSSFLOW

PARALLELFLOW

INTERNAL PASSAGEWAYS

NORMALPOSITION

 AB

PT

 AB

PT

SHI FTEDPOSI TION I NFINI TEPOSITI ON

CONTROL VALVES

 ATTACHMENT

MANUALSHUTOFF

SHUTTLE PIL OTCONTROLLED

Hydraulic Symbols (Electrical)

Electrical Symbols Table

325-AG135 PK-14

Circuit IdentificationNumber 

Wire Color  Wire Gauge

Harness identification codeThis 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

(EXAMPLEVA LVE)

Current Standard

Transducer (Fluid)

Transducer (Gas / Air)

G

Generator 

Electrical WirePressure Switch

MElectricMotor 

Pressure Switch

(Adjustable)

Temperature Switch

T

PressureSymbol

TemperatureSymbol

LevelSymbol

FlowSymbol

Electrical Symbols (Electrical)

Volume 1 of 2: Pilot (Center Pivot)

KENR5490-01 April2010

450E Backhoe Loader Hydraulic System

EBL1-UP

©2010 Caterpillar 

 AllRights Reserved

Printed in U.S.A.

COMPONENT LOCATIONS

31

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

2829

T ap D es c ri p t io n

T 1 P um p Di sc ha rg e

T2 Load Sense

S OS O il S am pl in g

TAP LOCATIONS

( A) Outlet Manifold(B) Left Stabilizer ControlValve

(C) Extendable Stick ControlValve(D) Bucket ControlValve(E) Swing ControlValve

(F) Stick ControlValve(G) Boom ControlValve

 A B C D E F G H   I

BACKHOE VALVE 29

The 450Emachines are equipped with a pilot controlled backhoe valve that is visible with the floor plate at the rearof the cab removed.

This illustration shows a eight bank backhoe valve. The components in the backhoe valve are:

SOSImplement andSteering Pump

HYDRAULIC OIL FILTER

SOS Filter Bypass Switch

6

The 450Emachines are equipped with a mechanicallycontrolled loader valve as shown in this illustration.

The loader valve is accessed from belowthe floorplate. The loader controlvalve group contains:

LOADER VALVE

E

28

DC

B

 A

Travel at high speeds over rough terrain causes bucket movement. TheoptionalRide ControlSystem acts as a shock absorber by absorbingbucket forces, which stabilize the machine.

The Ride ControlSystem components include; ride controlrelay (A), ridecontrolsolenoids (B), ride control accumulator (C), and ride controlpressure switch (D).

Two solenoids are nowused on the "E" Series machines Ride ControlSystem.

The Ride ControlSystem, on machines with the optional autoshifttransmission, is controlled by the Machine ECM. The Machine ECMmonitors the position of the ride controlswitch and determines when tooperate 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 nowincludes a torque controlsolenoid (not visible). The torque controlsolenoidprovides an additionalpump setting.

The implement and steering pump is located below the floor plate in the cab. The pump control

valve (H) contains a torque controlspooladjustment screw(B) and a flow compensator adjust-ment screw(A). The adjustment screws and the load sensing pressure tap (T2) are accessiblefrom the cab.

1

F

Viewof mechanically controlledloadervalvewithfloorplateremoved.

Loader Valve

These illustrations show the implement and steering pump out of the machine. The following compo-

nents are visible:

Torque controladjustment ( A), Flow compensator adjustment (B), Load sensing pressure tap ( T2),

Inlet port (C), Case drain port (D), Torque controlsolenoid (E), Discharge pressure tap (T1), Torquelimiter (F), Outlet port (G)

BC D

THREE BANK VALVE:

JK

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 pedaleffort when braking. This illustration shows the boosted brakes valve group, which usesoilfrom the pilot accumulator to add boost to the master cylinder. The hydraulic force multiplies the pedaleffort 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). Oilentersthe master cylinder through the supply hose (C) and exits the master cylinder through the return hose(D). The oilflows 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 sectionalview of the boosted brake valve group. When the brake pedalisdepressed, the boost brake valve moves to the left and inle t oilfrom the pilot ma nifold is directedto the master cylinder.

BOOSTED BRAKES

J

KDrain

EIGHT BANK VALVE (PILOT OPERATED)

For other bank valveconfigurations see KENR5488(Specifications Manual).

T3

The pilot manifold  can also beaccessed 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 andbackhoe pilot controlvalves.

Pilot Manifold

Viewof pilot controlledbackhoevalvewithfloorplateremoved.

The hydraulic oil fi lter is located below themachine at the left frame rail. The hydraulic oilfilter bypass switch is mounted to the oilfilterbase.

(H) Auxiliary ControlValve(I) Right Stabilizer ControlValve

(J) Pilot On/Off Solenoid Valve(K) Inlet Manifold(L) APorts

(M) BPorts(N) Load SignalRelief Valve

( A)Outletmanifold.

(B)Auxiliarycontrol valve.

(J)Makeupandreliefvalve.

(C)Tiltcontrol valve.

(D)Liftcontrol valve.

(E)Inletmanifold.

(M)PriorityValve.

(F)Loadsignal reliefvalve.

(N)Mechanic al detent for thefloat.(P)A ports.

(R)B ports.

SOS

ECM

To WheelBrake

Boost BrakeValve

From Pilot Accumulator 

To Tank

MasterCylinder 

SlaveCylinder 

 A BE D C

T 3 P il ot P re ss ur e

2 3 2 4 2 5

NOTE: Alpha numeric numbers are represented by the number only on the machine views.

22

29 22

19

1918

18

2 7 2 6

27

26

Hydraulic OilFilter 

Temp Sensor 

Filter BypassSwitch

Temp Sensor 

L

M

Implement andSteering Pump

 A

B

T2C

Loader Valve

H

ITEM NAME 450E (PILOT) 450E (MECH)

1 P UMP G P . ( Pr i mar y) 269-9336

2 P UMP G P . ( S ec ondar y) 280-7873

4 T AN K GR OU P 245-0169

5 C OO LE R N/A

6 F ILT ER 307-9799

7 HMU 210-6240

8 S TE ER C YL .

9 LIFT CYL.

1 0 T IL T C YL . 100-7844

11 M P B UCKE T CY L.( O PT )

12STABILIZER CYLNDERS

12A LH 270-7290

12B RH 270-7291

13 BOOM CYLINDER 270-7285

14 STICK CYL. 270-7286

1 5 S WI NG C Y L. 286-8903

16 BUCKET CYL. 270-7287

17 E - ST I CK CY L( O P T ). 270-7288

VALVE GROUP (2-BANK)

18 P I LO T - LEV E RW / DT NT & S W T CH 223-4715

1 9 PI LO T 267-2758

22 A CCUM ULA TO R 226-0420

23 RI DE CNT RLV A LV E ( O P T) 245-8780

24 RI DE CNT RLA CCMLT R( O PT ) 162-3960

25 RI DE CNT RP RE S. S W TCH( O PT ) 304-5696

26 T E MP . SE NSO R 246-4297

27 DIFF. PRES. SWITCH 134-0404

28

LOADER VALVE

2 BANK 271-0512

3 BANK 271-0513

28A I NLE T S E CTI O N 271-0520

28B L I FT S E CT IO N 271-0521

28C T I LT S E CT IO N 271-0522

28D A UX S E CT I ON 271-0523

28E O UTLE T M A NI F OLD 269-1079

29

BACKHOE VALVE

7 BANK 271-0527

8 BANK 271-0527

29A I NLE T S E CTI O N 269-1062

29B STABILIZERSECTION 271-0541

29C A UX S E CT I ON 271-0547

29D B O OM S E CT IO N 271-0542

29E S T ICK S E CT I ON 271-0543

29F S W ING S E CTI O N 271-0544

29G BUCKET SECTION 271-0545

29H E - ST I CK S E CT IO N 271-0546

29J O UTLE T M A NIF O LD 271-0539

29K PATTERNSWITCHING VALVE 299-9072

21 V ALV E G P - CUS HI O NRE LIE F 283-6331

30 V ALV E G P - CUTO F F 260-3022

31 PRESSUREREUDCINGVALVE 300-0430

20 M A NI F OLD- P I LO T 268-0094

226-5540

238-5285

125-7895

COMPONENT LIST

3 H YD R AU L IC T A NK 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 returnto dig function.

For other bank valveconfigurations seeKENR5488(Specifications Manual).

4

4

Note: The auxiliary ControlValve (H) is not avalible on the optional seven bank valve.

8/18/2019 Cat 450E Backhole Loader Hydraulic System

2/4

   K

   E   N   R   5   4   9   0 -   0

   1   V   O   L   1

   3   0   P  a  g  e ,   (   D   i  m  e  n  s   i  o  n  s  :   3   9   i  n  c   h  e  s  x   2   8   i  n  c   h  e  s   )

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/ RETURNLINE

HYDRAULICCIRCUITCOLORDESCRIPTIONSIMPLEMENTand STEERING PUMPCIRCUIT

SWING CYLINDERCIRC UIT

STEERING CYLINDERCIRCU IT

PILOTOILCIRCU IT

BUCKETCYLINDER CIRCUIT

STICKCYLINDER CIRCUIT

LOADSENSECIRC UIT

SUPPLYLINE

 AUXILIARYCIRCUIT (BACKHOEVALVE)

E-STICKCYLINDER CIRCUIT

BOOM CYLINDERCIRC UIT

STABILIZERCYLINDERCIRC UIT

BOOSTEDBRAKEOIL CIRCUIT

LIFTCYLINDER CIRCUIT

TILTCYLINDERCI RCUIT

 AUXILIARYCIRCUIT (LOADERVALVE)

THISSCHEMATICISFORTHE450EBACKHOELOADERS

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 Manualfor Troubleshooting, Specifi cations and Systems Operations

ITEM VALVE 4 50 E PI L OT 4 50 E ME CH AN IC AL

P1 L SR EL IEF L O AD ER SYSTEM PR ESSUR E2 44 00 kPa ( 2 20 0 k Pa M ARG I N)

P2 L SR EL IEF BAC KH O E SYSTEM PR ESSUR E2 62 00 kPa ( 2 20 0 k Pa M AR GI N )

P 3 H MU L S RE LI EF S YS TE M P RE SS UR E 18 70 0 k Pa (2 20 0 k Pa MA RG IN )

P4 TILT RE 26000 kPa

P5 TILT HE 26000 kPa

P6 LOADER AUX HE 24500 kPa

P7 STA BI LIZ ER RE (T HERMA LRE LIE F) 29000 k Pa

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 BACKHOEAUX 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 the7 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

LEFTBRAKEPEDAL

RIGHTBRAKEPEDAL

TO REARAXLE

LEFTWHEELBRAKE

TO REARAXLE

RIGHTWHEELBRAKE

DEL

28

T3

T2

T1

12B 13 14

15

2116 17

12A

29J29B29H29G29F

29K

29D29B29A

22

29

28A

28B

28C

28D

11

109

25

24

23

18

19

29E

SOS

7

8

28E

2

 AUX.

6

P16

P17

P18

30

*29C

31

P2

P1

P20

P7

P14

P8P13P11

P12

P10

P9

P15P7

PR1

P19

P3

P6

P5 P4

P1

8/18/2019 Cat 450E Backhole Loader Hydraulic System

3/4

   K

   E   N   R   5   4   9   0 -   0

   1   V   O   L   2

   3   0   P  a  g  e   (   D   i  m  e  n  s   i  o  n  s  :   3   9   i  n  c   h  e  s  x   2   8   i  n  c   h  e  s   )

ONEPOSITION TWO POSITION THREEPOSITION

V ENT ED P RE SS URI ZE D RETURNABOVEFLUIDLEVEL RETURNBELOWFLUIDLEVEL

LINESCROSSING LINESJOINING

TWO-WAY THREE-WAY FOUR-WAY

SPRING CONTROLVALVES RESTRICTION LINERESTRICTION

(FIXED)

2-SECTIONPUMP

MAINAUX.

SPRING

(ADJUSTABLE)

VARIABILITY LINERESTRICTION

(VARIABLE)

LINERESTRICTIONVARIABLEand PRESSURE

COMPENSATED

PRESSURE

COMPENSATION

PUMP: VARIABLEandPRESSURECOMPENS ATED

ENERGYTRIAN GLES

HY DRA ULIC P NE UMA TIC

MEASUREMENT

PRESSURE TEMPERATURE FLOW

ROTATING SHAFTS

UNIDIRECTIONAL BIDIRECTIONAL

PUSH-PULL LEVER PEDALGENERAL MANUAL PUSH BUTTON SPRING

MANUAL CONTROL SYMBOLS

HYDRAULICMOTORS

FIXED

DISPLACEMENT

VARIABLEDISPLACEMENT

NON-COMPENSATED

UNIDIRECTIONAL

BIDIRECTIONAL

HYDRAULICPUMPS

FLUIDSTORAGE RESERVOIRS

CROSSING ANDJOINING LINES

VALVE ENVELOPES VALVE PORTS

BASICCOMPONENT SYMBOLS

FLUIDCONDITIONERPUMPor MOTOR

FLUID POWER SYMBOLS

FIXED

DISPLACEMENT

VARIABLEDISPLACEMENT

NON-COMPENSATED

UNIDIRECTIONAL

BIDIRECTIONAL

VALVES

PILOT CONTROL SYMBOLSRELEASEDPRESSURE

EXTERNALRETURN INTERNALRETURN

REMOTESUPPLYPRESSUR E

SIMPLIFIED COMPLETE INTERNAL

SUPPLYPRESSURE

 ACCUMULATORS

SPRING LOADED GASCHARGED

SOLENOIDor MANUAL

SOLENOIDand PILOT

SOLENOIDandPILOTor MANUAL

COMBINATIONCONTROLS

SOLENOID SERVO THERMAL DETENT

HYDRAULICANDPNEUMATICCYLINDERS

DOUBLEACTINGSINGLEACTING

BASICSYMBOL

SPRINGLOADED

CHECK VALVES

TWO

POSITIONINFINITE

POSITIONING

FLOWINONEDIRECTION

FLOWALLOWEDINEITHERDIRECTION

THREE

POSITION

CROSSFLOW

PARALLELFLOW

INTERNAL PASSAGEWAYS

NORMALPOSITION

 AB

PT

 AB

PT

SHI FTEDPOSI TION I NFINI TEPOSITI ON

CONTROL VALVES

 ATTACHMENT

MANUALSHUTOFF

SHUTTLE PIL OTCONTROLLED

Hydraulic Symbols (Electrical)

Electrical Symbols Table

325-AG135 PK-14

Circuit IdentificationNumber 

Wire Color  Wire Gauge

Harness identification codeThis 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

(EXAMPLEVA LVE)

Current Standard

Transducer (Fluid)

Transducer (Gas / Air)

G

Generator 

Electrical WirePressure Switch

MElectricMotor 

Pressure Switch

(Adjustable)

Temperature Switch

T

PressureSymbol

TemperatureSymbol

LevelSymbol

FlowSymbol

Electrical Symbols (Electrical)

Volume 2 of 2: Mechanical (Center Pivot)

KENR5490-01 April2010

450E Backhoe Loader Hydraulic System

EBL1-UP

©2010 Caterpillar 

 AllRights Reserved

Printed in U.S.A.

Note: The auxiliary ControlValve (C) is not avalible on the optional seven bank valve.

ITEM NAME 450E (PILOT) 450E (MECH)

1 P UMP G P . ( Pr i mar y) 269-9336

2 P UMP G P . ( Sec ondary ) 280-7873

4 T AN K GR OU P 245-0169

5 C OO LER N/A

6 F IL TER 307-9799

7 HMU 210-6240

8 S TE ER C YL .

9 LIFT CYL.

1 0 T IL T CY L. 100-7844

11 M P B UCKE T CY L.( O PT )

12STABILIZER CYLNDERS

12 A L H 270-7290

12 B R H 270-7291

13 BOOM CYLINDER 270-7285

14 STICK CYL. 270-7286

1 5 S WI NG C YL . 286-8903

16 BUCKET CYL. 270-7287

17 E - ST I CK CYL( O P T ). 270-7288

VALVE GROUP (2-BANK)

18 P I LO T - LEV E RW / DT NT & S W T CH 223-4715

1 9 P IL OT 267-2758

22 A CCUM ULA TO R 226-042023 RI DE CNTRLV A LVE ( O P T ) 245-8780

24 RI DE CNTRLA CCMLT R( O PT ) 162-3960

25 RI DE CNTRP RE S . S W TCH( O PT ) 304-5696

26 T E MP . SE NSO R 246-4297

27 DIFF. PRES. SWITCH 134-0404

28

LOADERVALVE

2 BANK 271-0512

3 BANK 271-0513

28A I NLET S E CT IO N 271-0520

28B L I F T S ECT IO N 271-0521

28C T I LT S E CT IO N 271-0522

28D A UX S E CT I O N 271-0523

28E O UTLE T M A NI F OLD 269-1079

29

BACKHOE VALVE

7 BANK 271-0527

8 BANK 271-0527

29A I NLET S E CT IO N 269-1062

29B STABILIZERSECTION 271-0541

29C A UX S E CT I ON 271-0547

29D B O OM S E CTI O N 271-0542

29E S T ICK S ECT I ON 271-0543

29F S W ING S E CTI O N 271-0544

29G BUCKET SECTION 271-0545

29H E - ST I CK S ECT IO N 271-0546

29J O UTLE T M A NIF O LD 271-0539

29K PATTERNSWITCHING VALVE 299-9072

21 V A LV E G P - CUS HIO NRE LI EF 283-6331

30 V A LV E G P - CUT OF F 260-3022

31 PRESSUREREUDCINGVALVE 300-0430

20 M A NI F OLD- P ILO T 268-0094

226-5540

238-5285

125-7895

COMPONENT LIST

3 H YD RA UL IC T A NK 280-7873

271-0517

266-2558

271-0531

271-0537

271-0532

271-0533

271-0534

271-0535

271-0536

N/A

COMPONENT LOCATIONS

T ap D es c ri p t io n

T 1 P um p Di sc ha rg e

T2 Load Sense

S OS O il S am pl in g

TAP LOCATIONS

BACKHOE VALVE 29

SOSImplement andSteering Pump

HYDRAULIC OIL FILTER

SOS Filter Bypass Switch

6

LOADER VALVE 28

Travel at high speeds over rough terrain causes bucket movement. TheoptionalRide ControlSystem acts as a shock absorber by absorbingbucket forces, which stabilize the machine.

The Ride ControlSystem components include; ride controlrelay (A), ridecontrolsolenoids (B), ride control accumulator (C), and ride controlpressure switch (D).

Two solenoids are nowused on the "E" Series machines Ride ControlSystem.

The Ride ControlSystem, on machines with the optional autoshifttransmission, is controlled by the Machine ECM. The Machine ECMmonitors the position of the ride controlswitch and determines when tooperate the ride control system.

RIDE CONTROL

B

 A

C

D

IMPLEMENT / STEERING PUMP 1

Viewof mechanically controlledloadervalvewithfloorplateremoved.

Loader Valve

These illustrations showthe implement and steering pump out of the machine. The following components

are visible:

Torque controladjustment ( A), Flowcompensator adjustment (B), Load sensing pressure tap (T2), Inlet

port (C), Case drain port (D), Torque controlsolenoid (E), Discharge pressure tap (T1), Torque limiter(F), Outlet port (G)

BC D

E

G

 A

B

E

F

D C

D

E

C

T2

T1

T2

T1

The 450Emachi nes are equipped with hydraulically assisted master cylinders, which decreases theamount of pedaleffort when braking. This illustration shows the boosted brakes valve group, which usesoilfrom the pilot ac cumulator 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). Oilentersthe master cylinder through the supply hose (C) and exits the master cylinder through the return hose(D). The oilflows to the service brakes through the hoses (E) at the bottom of the master cyl inder.

The master cylinders can be removed from the machine from inside the operator's compartment.

This illustration shows a sectionalview of the boosted brake valve group. When the brake pedalisdepressed, the boost brake valve moves to the left and inl et oilfrom the pilot manifold is directed

to the master cylinder.

BOOSTED BRAKES

Drain

For other bank valveconfigurations seeKENR5488(Specifications Manual).

T3

The pilot manifold  can also beaccessed 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 andbackhoe pilot controlvalves.

Pilot Manifold

Viewof pilot controlledbackhoevalvewithfloorplateremoved.

The hydraulic oil fi lter is located below themachine at the left frame rail. The hydraulic oilfilter bypass switch is mounted to the oilfilterbase.

SOS

ECM

To WheelBrake

Boost BrakeValve

From Pilot Accumulator 

To Tank

MasterCylinder 

SlaveCylinder 

 A BE D C

T 3 P il ot P re ss ur e

2 3 2 4 2 5

NOTE: Alpha numeric numbers are represented by the number only on the machine views.

Hydraulic OilFilter 

Temp Sensor 

Filter BypassSwitch

Temp Sensor 

( A) Outlet Manifold(B) Left Stabilizer ControlValve

(C) Auxiliary ControlValve(D) Extendable Stick ControlValve(E) Bucket ControlValve

(F) Swing ControlValve(G) Stick ControlValve

 A B CD E F G H   I

The 450Emachines are equipped with a pilot controlled back hoe valve that is visible with the floor plate at therear of the cab removed. This illustration shows a eight bank backhoe valve in the 450E Backhoe Loader. Thecomponents in the backhoe valve are:

J

K

EIGHT BANK VALVE (MECHANICALLYOPERATED)

(H) Boom ControlValve(I) Right Stabilizer ControlValve

(J) Pilot On/Off Solenoid Valve(K) Inlet Manifold(L) APorts

(M) BPorts(N) Load SignalRelief Valve

L

M

The implement and steering pump on the 420Eand 430E machines is similar to the "D"Series machines, but nowincludes a torque control solenoid (not visible). The torquecontrolsolenoid provides an additionalpump setting.

The implement and steering pump is located below the floor plate in the cab. The pumpcontrolvalve (H) contains a torque controlspooladjustment screw(B) and a flowcompen-sator adjustment screw(A). The adjustment screws and the load sensing pressure tap (T2)

are accessible from the cab.

Implement andSteering Pump

 A

B

T2C

Loader Valve

H

Drain

31

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

2829

The 450Emachines are equipped with a mechanicallycontrolled loader valve as shown in this illustration.

The loader valve is accessed from below the floorplate. The loader controlvalve group contains:

E

DC

B

 A

F

THREE BANK VALVE:

JK

M

P

R

N

( A )Outletmanifold.

(B )Auxiliarycontrol valve.

(J)Makeupandreliefvalve.

(C)Tilt control valve.

(D)Liftcontrol valve.

(E)Inletmanifold.

(M)PriorityValve.

(F)Loadsignal relief valve.

(N)Mechanica l detent for thefloat.(P)A ports.

(R)B ports.

22

29 22

19

1918

18

2 7 2 6

27

26(K)Magnetic detent for returnto dig function.

For other bank valveconfigurations seeKENR5488(Specifications Manual).

4

4N

8/18/2019 Cat 450E Backhole Loader Hydraulic System

4/4

   K   E   N   R   5   4   9   0 -   0

   1   V   O   L   2

   3   0   P  a  g  e ,   (   D   i  m  e  n  s   i  o  n  s  :   3   9   i  n  c   h  e  s  x   2   8   i  n  c   h  e  s   )

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)

THISSCHEMATICISFORTHE450EBACKHOELOADERS

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 Manualfor Troubleshooting, Specifi cations and Systems Operations

ITEM VALVE 4 50 E PI L OT 4 50 E ME CH AN IC AL

P1 L SR EL IEF L O AD ER SYSTEM PR ESSUR E2 44 00 kPa ( 2 20 0 k Pa M ARG I N)

P2 L SR EL IEF BAC KH O E SYSTEM PR ESSUR E2 62 00 kPa ( 2 20 0 k Pa M AR GI N )

P 3 H MU L S RE LI EF S YS TE M P RE SS UR E 18 70 0 k Pa (2 20 0 k Pa MA RG IN )

P4 TILT RE 26000 kPa

P5 TILT HE 26000 kPa

P6 LOADER AUX HE 24500 kPa

P7 STA BI LIZ ER RE (T HERMA LRE LIE F) 29000 k Pa

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 BACKHOEAUX 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

LEFTBRAKEPEDAL

RIGHTBRAKEPEDAL

TO REARAXLE

LEFTWHEELBRAKE

TO REARAXLE

RIGHTWHEELBRAKE

DEL

28

T3

T2

T1

12B 13 14

15

2116 17

12A

29J29B29H29G29F29D29B29A

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

P8P13P11

P12

P10

P9

P15P7

PR1

P1

P5 P4

P6

P3

P19

*Aux Section not avalible on the7 Bank Valve configuration.