428c esQUEMA HIDRAULICO

SENR1210-03 January 1999

428C & 438C Backhoe Loaders Hydraulic & Steering System 428C

438C

8RN1-UP

9KN1-UP

1HR1-UP

1JR1-UP

1SR1-UP

1TR1-UP

2CR1-UP

2DR1-UP

©1999 Caterpillar   All Rights Reserved

Printed in U.S.A.

     3      0        0      1      2      1      R      N      E      S

27 26 1

4

2

5

7

6

8

Single Tilt 3

L

9

R

10

12

11

14 13

15

16

17

20

19

18

Item No.

2WSSteeringMeteringPump

3

 AWSSteering Metering Pump

4

 AWSBrake ControlValve

7 8 9

44

45

LS

T

P

43

41

42

28 39

16 15

P LS

27

25

26

23

24

22

21

T

48 36 32

31

33

30

21

29

13

28

11

8

10

7

8

46

37

35

26

44 36

18

3 4

17

 AWSRear AxleBrakes

2

LoaderValveGroup  Auxillary ControlValve (Optional)

4

SideShiftCylinders

10

CheckValve

11

Side Shift Solenoid Valve

12

ExtendibleStickCylinder (Optional)

13

ExtendibleStickControlValve(Optional)

14

StickCylinder 

15

BackhoeBucketCylinder 

16

ExtendibleStickBucketCylinder (Optional)

17

LeftStabilizingCylinder 

20 9

45 41 48

19

1

34 47

6

39

40

5

38 42 43

RightStabilizerCylinder  SwingCylinders

20

Boom Cylinder 

21

Shut Off Valve

22

BoomControlValve

23

SwingControlValve

39

24

RightStabilizerControlValve

40

 AWSRear Steering Cylinder (Optional)

25

LeftStabilizerControlValve

41

 AWSSteering V alve and Mounting Group (Optional)

26

BucketControlValve

27

StickControlValve

28

TiltControlValve

29

LiftControlValve

34 35

37 38

42 43 44

Piston Type Hydraulic Pump HydraulicOilTank HydraulicOilCooler   AWSOilPressure Switch RideControlPressureSwitch LiftCylinders

RideControlAccumulator(Optional) RideControlSolenoidValve (Optional) Tilt Cylinder 

45

 AWSValveAssembly

46

 AWSBrake Reservoir Tank Group

30

 AWS3 Bank Valve (Optional)

P LS

31

 AWSInlet Manifold and Steering Priority ValveGroup

48

Orifice Diameter 1.5 mm (0.06 in)

T

32

2WS3BankValve(Optional)

49

Orifice Diameter 0.4 mm (0.02 in)

33

2WSInletManifoldandSteeringPriority ValveGroup

50

Orifice Diameter 1.2 mm (0.05 in)

34

50

35

30

31

22

19

29

49

32

23

MultipurposeBucketCylinders(Optional)

36

37

33

24

18

40

38

14

FrontSteeringCylinder 

2

6

46

Component

1

5

47

12

HydraulicSchematic-SingleTilt

25

47

ReturnLineHydraulicOilFilter 

29 28 1

2

4

6

5

8

7

9

11

12

13

14

16 15

17

19

20

22

21

16 Hydraulic Schematic - ParallelLift

1

50 'B'

49

T

P

2WSSteering Metering Pump  AWSSteeringMeterin g Pump

4

Multipurpose Bucket Cylinders (Optional)

5

Broom Motor (Optional)

6

Pin Coupler Cylinder (Optional)

8

42

'A'

46

48 44

45 41

53 P

29

LS T

52

30  A

B

54 38

37

36

35

34

34

15

33

20

13

10

19

12

9

10

32 33

31

P LS T

28

27

26

25

24

23

38 40

31

3029

3

18 32

22

2

39

50

6

ManualShut Off Valve (Optional) Loader Valve Group  Auxilla ry ControlVal ve (Option al)

11

11

Side Shift Cylinders

12

Check Valve

13

Side Shift Solenoid Valve

14

Extendible Stick Cylinder (Optional)

15

Extendible Stick ControlValve (Optional)

16

Stick Cylinder 

46

17

Backhoe Bucket Cylinder 

47

18

Extendible Stick Bucket Cylinder (Optional)

19

Left Stabilizing Cylinder 

37

Piston Type HydraulicPump

20

Right Stabilizer Cylinder 

38

Hydraulic OilTank

Swing Cylinders

39

Hydraulic OilCooler 

40

 AWSOilPressureSwitch

41

Lift ControlValve

49

48

22

Boom Cylinder 

23

Shut Off Valve

24

Boom ControlValve

25

Swing ControlValve

44

Lift Cylinders

26

Right Stabilizer ControlValve

45

 AWSRear Stee ring Cyli nder (Opti onal)

27

Left Stabilizer ControlValve

46

Ride ControlSolenoid Valve (Optional)

28

Bucket ControlValve

47

Ride ControlAccumulator (Optional)

29

StickControlValve

48

 AWSSteeringValve a nd Mou nting Gro up

30

 AWSRear Axl e Brakes

49

 AWSValve A ssembl y

31

 AWSBrake Re servoir T ank Grou p

50

Tilt Cylinders

32

51

ReturnLine HydraulicOilFilter 

 AWSBrake Co ntrolValve

33

 AWS3 Bank V alve (Opti onal)

34

 AWSInlet Man ifold an d Steerin g PriorityValve G roup

54

Orifice Diameter 1.2 mm (0.05 in )

35

2WS3 Bank Valve (Optional)

 A

Fluid from AWSbrake valve to AWSsteering valve

36

2WSInlet Manifold and Steering Priority Valve Group

43

52 53

B

1

30

21

42

39

35

23

17

Coupler Valve and Mounting Group (Optional)

10

21

43

Front Steering Cylinder 

3

7

LS

Component

2

9

40

36

24 14

18

ItemNo.

47

41

25

R

L

51

42

26

Parallel Lift

3

     3      0        0      1      2      1      R      N      E      S

27

10

51

Tilt ControlValve Ride ControlPressure Switch (Optional)

Orifice Diameter 0.4 mm (0.02 in) Orifice Diameter 1.5 mm (0.05 in)

Signalfron AWSbrake reservoir to AWSsteering valve

45

37

44 43

4 5 6 7 8