Takeuchi Hydraulic excavator TB1140 (Serial No. 514400002~). Operator's Manual

DISASSEMBLY AND ASSEMBLY

HYDRAULIC PUMP (MAIN)

10. Position the pump parallel under the attachment sur-

face for the regulator.

11. Attach the first gear (116) to the block (312).

12. Affix the casings (271) and (272) and the block (312)

in place using cap screws.

• Attach the block so that the regulator is on top and

the intake flange is to the right as viewed from the

front.

Cap screw: 240 N·m

13. Install the gear pump (04).

Cap screw: 17 N·m

14. Insert the PTO unit (05) into the block (312).

• Be sure to insert the PTO unit in the proper direc-

tion.

Cap screw: 33 N·m

HYDRAULIC PUMP (MAIN)

4I0AS00

DISASSEMBLY AND ASSEMBLY

HYDRAULIC PUMP (MAIN)

Inspection and adjustment

Checking the parts

Item

Criteria

Action

Piston and cylinder block

When the width of the clearance (S) between

Replace

the piston and cylinder block assembly is above

0.056 mm (0.0022 in.)

When there is damage, scratches, abnormal

wear, or other problems present on the surfaces

of sliding parts

S = D-d

4I0AF22Z

Amount of looseness be-

When the amount of looseness (S) between the

Replace

tween the piston and

piston and shoe is above 0.3 mm (0.011 in.)

shoe

Shoe thickness

When the thickness (t) of the shoe is below

Replace

3.7 mm (0.15 in.)

Spring

When the free height of the spring is below

Replace

40.3 mm (1.59 in.)

Plate and bushing as-

When the height (H-h) of the assembled plate

Replace

sembly

and bushing is below 15. 8 mm (0.62 in.)

Seals, O-rings

—

During reassembly after parts disassembled

Replace

Shafts and oil seals

—

When there is abnormal damage, wear, or sei-

Replace

zure on relevant surfaces

Valve plate

Plate

HYDRAULIC PUMP (MAIN)

4I0AS00

DISASSEMBLY AND ASSEMBLY

HYDRAULIC PUMP (SUB)

Disassembly and assembly

The numbers in parentheses, ( ), listed after the names of

parts throughout this document do not necessarily match

the numbers of the same parts listed in the construction

diagrams and parts lists. The numbers listed are for part

numbers used in illustrations.

General precautions

•

Perform disassembly and assembly work in a clean

place. Provide clean containers to hold parts during

disassembly.

•

Clean around the ports before disassembly. Remove

paint around connectors with a wire brush.

•

Clean the disassembled parts with wash oil.

•

Put alignment marks on all parts to ensure that they are

reassembled in the same positions.

•

After each disassembly, replace all seals and apply a

thin layer of grease to each.

•

Check each part for abnormal wear or seizing. Re-

move any burrs with sandpaper.

•

Remove adhesive from screw holes that use adhesive

through the tap. Do not reuse mounting bolts or

screws.

•

Do not use cloth gloves during assembly. Fibers from

the gloves could fall off and clog valves, etc., which

could cause parts to become faulty.

•

During assembly, be sure to apply clean hydraulic oil

to all moving parts in and sliding parts that come into

contact with the hydraulic motor and valve parts be-

fore installing or attaching the part.

•

Plug all ports once assembly has been completed in

order to prevent dust and dirt from entering.

•

Do not attempt to adjust the adjusting screws at times

other than when necessary.

HYDRAULIC PUMP (SUB)

4I1AS00

DISASSEMBLY AND ASSEMBLY

HYDRAULIC PUMP (SUB)

Disassembly

1. Remove the cap screws

Cap screw: 88.2 N·m to 93.1 N·m

4IAB02Z

2. Remove the flange (1).

3. Remove the gasket (2) from the flange (1).

4. Remove the snap ring (3) and the oil seal (4) from the

flange (1).

• Be careful not to scratch or otherwise damage the

flange.

• When assembling, install the oil seal using the jigs

“A” and “B”.

4IAB04Z

HYDRAULIC PUMP (SUB)

4I1AS00

DISASSEMBLY AND ASSEMBLY

HYDRAULIC PUMP (SUB)

5. Remove the rear cover (5).

6. Remove the gasket (6) from the rear cover (5).

7. Disassemble the front pump.

a. Remove the bushing “A” (7), the bushing “B” (8),

the drive gear (9), and the driven gear (10) from

the housing.

• Be careful not to mix up the bushings.

• Be careful not to scratch or otherwise damage

the inner part of the housing.

8. Remove the gaskets (11) and (12) from the bushing

“A” (7) and the bushing “B” (8).

9. Disassemble the rear pump using the same proce-

dure as for the front pump.

Assembly

For assembly, refer to the construction diagram and re-

verse the disassembly procedure.

HYDRAULIC PUMP (SUB)

4I1AS00

DISASSEMBLY AND ASSEMBLY

HYDRAULIC PUMP (SUB)

Inspection and adjustment

Checking the parts

After checking the disassembled parts for dirt or discol-

oration, clean them with diesel fuel. However, do not let

diesel fuel get on rubber parts. Check each part for the

following points and if there is any trouble, repair or re-

place the part.

Housing

The gear pump is made so that the crests of the gear

teeth make light contact with the housing walls as a

means of increasing its efficiency. Therefore, contact

marks can be seen near the suction port in any pump that

has been operated. It is normal if the depth of the contact

marks is within 0.1 mm. If the depth exceeds the usage

limit in the above figure, replace the pump assembly.

SUCTION SIDE

ANSAUGSEITE

CÔTÉ D'ASPIRATION

DISCHARGE SIDE

CONTACT MARKS

ABGABESEITE

KONTAKTMARKIERUNGEN

COTE DECHARGE

MARQUES DE CONTACT

4IAB08Z

4IAB09Z

HYDRAULIC PUMP (SUB)

4I1AS00

DISASSEMBLY AND ASSEMBLY

HYDRAULIC PUMP (SUB)

Bushing

The ideal situation is for the sliding surfaces to have no

roughness and for the suction side half to be lustrous. Al-

so, it is satisfactory if strong contact marks can be seen

on the side surface on the suction side and minute con-

tact marks can be seen on the discharge side.

Replace the bushing if it is in the following condition.

• Contact marks can be seen on the sliding surface of

the entire bearing inner diameter and it is rough with

scratches that easily catch a fingernail.

• There are many scratches around the circumference

of the side surface and it is rough with scratches that

easily catch a fingernail.

• There are marks due to trapping of foreign matter on

the sliding surface of the bearing inner diameter and

the side surface.

Dirty hydraulic oil is one likely cause of such wear. In

such a case, replace the hydraulic oil and flush out the

affected hydraulic circuit completely.

Other likely causes are as follows.

• There is excessive load caused by damage to the re-

lief valve.

• There is cavitation or aeration.

• The hydraulic oil temperature is too high.

• The hydraulic oil is deteriorated.

• The viscosity of the hydraulic oil is too low.

If it becomes necessary to replace the bushings, it

means that the gear shaft and gear side surfaces are

also rough or worn severely, and the gears will thus also

need to be replaced at the same time as the bushings.

The dimensions for the bushing use limit are shown in the

figure on the right.

Gear

Replace any gear that is found to be in any of the below

conditions.

1. The shaft or gear side surfaces are rough with

scratches that can become easily caught on a finger-

nail.

2. There are cracks in the tooth roots or extremely ab-

normal wear to the tooth surfaces.

The shaft size for the gear use limit is shown in the figure

above.

HYDRAULIC PUMP (SUB)

4I1AS00

DISASSEMBLY AND ASSEMBLY

HYDRAULIC PUMP (SUB)

Seals

• Check oil seals for scratches in the seal surface, wear,

deformation, or deterioration of the rubber’s elasticity.

If any such problems are found, replace the faulty part.

• Replace the seals whenever the hydraulic pump is dis-

assembled.

• Check the backup ring for scaling and cutting. If any

such problems are found, replace the faulty part.

Test operation

The best method for testing pump operation is to mount

the pump under test onto a test stand. However, if it is not

possible to do so, use an actual machine in which the

pump to be tested is mounted.

If any abnormal wear is discovered during disassembly,

be sure to replace the hydraulic oil and return filter.

1. Insert a pressure gauge into the high-pressure pip-

ing near the pump.

2. Run the engine at 500 min^-1 to 1000 min^-1, and set

the control valve to the neutral position.

3. Run the pump for 10 minutes under the conditions

listed in 2 above, and increase the engine speed to

1500 min^-1 to 2000 min^-1 and then let the engine run

for another 10 minutes.

4. Next, run the pump for 5 minutes at a time for each

additional 1.96 MPa to 2.94 MPa of pressure until it

reaches the rated pressure.

After operating each circuit for about 5 minutes, replace

the return filter or clean it.

During the process of raising the pressure, pay careful

attention to the oil temperature, the pump surface tem-

perature, and the operating noise. If the oil temperature

or the pump surface temperature becomes abnormally

high, eliminate the load from the pump and let the tem-

perature drop before resuming the test.

Measuring the discharge volume

After completing the test operation, measure the dis-

charge volume.

1. Connect a tester (1) to the discharge side of the

pump (2).

• Be sure to connect the tester to the proper side.

2. Open the loading valve on the tester, and start the

engine.

3. Run the engine at the rated speed.

4. Gradually close the loading valve and apply the rat-

ed pressure to the pump (2).

5. Measure the discharge volume and the pump engine

4IAB10Z

speed in rpm.

HYDRAULIC PUMP (SUB)

4I1AS00

DISASSEMBLY AND ASSEMBLY

CONTROL VALVE

Arm 1

Boom 2

Slew

1st auxiliary line

Travel (R)

2nd auxiliary line

Blade

Swing

Arm 2

Boom 1

a Bucket

b Travel (L)

c Travel forward

1. O-ring

19. Plug

37. Spool end

53. Cap screw

2. O-ring

20. Plug

38. Cap

54. Cap screw

3. O-ring

21. Poppet

39. Cap

55. Cap screw

4. O-ring

22. Spring

40. Plug

56. Plug

5. O-ring

23. Poppet

41. Orifice

57. Plug assembly

6. O-ring

24. Poppet

42. Cap

58. Bolt

7. Backup ring

25. Spring

43. Relief valve

59. Nut

8. O-ring

26. Spacer

(Negative control)

60. Bolt

9. O-ring

27. Anti-drift valve

44. Orifice

61. Nut

10. O-ring

28. Plug assembly

45. Poppet

62. Swing section

11. Cap

29. Sleeve

46. Spring

63. Inlet housing

12. Cap

30. Poppet

47. Outlet housing

64. Main relief valve (Pr)

13. Cap

31. Spring

48. Main relief valves

65. 2nd auxiliary line section

14. Poppet

32. Poppet

(P1, P2)

66. Plug assembly

15. Spring

33. Spring

49. Port relief valve

67. Blade section

16. Plug

34. Flange

50. Port relief valve

17. Plug assembly

35. Spring holder

51. Port relief valve

18. Plug assembly

36. Spring

52. Cap screw

CONTROL VALVE

4J0AS00

DISASSEMBLY AND ASSEMBLY

CONTROL VALVE

Main relief valves (P1, P2)

11 13 14

1. Plug

8. O-ring

2. Sleeve

9. Backup ring

3. Main poppet

10. O-ring

4. Piston

11. O-ring

5. Needle valve

12. Set screw

6. Spring

13. Washer

N0D207

7. Spring

14. Nut

Main relief valve (Pr)

1. Plug

8. O-ring

2. Sleeve

9. Backup ring

3. Main poppet

10. O-ring

4. Piston

11. O-ring

5. Needle valve

12. Set screw

6. Spring

13. Washer

7. Spring

14. Nut

Port relief valve

13 12

1. Housing

10. Set screw

2. Plug

11. Washer

3. Poppet

12. Nut

4. Poppet

13. O-ring

5. Piston

14. O-ring

6. Needle valve

15. Backup ring

7. Spring

16. O-ring

8. Spring

17. O-ring

N0D208

9. Spring

18. Backup ring

CONTROL VALVE

4J0AS00

DISASSEMBLY AND ASSEMBLY

CONTROL VALVE

Disassembly and assembly

WARNING

• Be careful as the springs and spring seat may pop out

when the caps are removed.

• Oil may spurt out if caps or filters are removed or pipes

are disconnected before the pressure in the hydraulic

system is released.

The numbers in parentheses, (), listed after the names of

parts throughout this document do not necessarily match

the numbers of the same parts listed in the construction

diagrams and parts lists. The numbers listed are for part

numbers used in illustrations.

General precautions

•

Perform disassembly and assembly work in a clean

place. Provide clean containers to hold parts during

disassembly.

•

Clean around the ports before disassembly. Remove

paint around connectors with a wire brush.

•

Clean the disassembled parts with wash oil.

•

Put alignment marks on all parts to ensure that they are

reassembled in the same positions.

•

After each disassembly, replace all seals and apply a

thin layer of grease to each.

•

Check each part for abnormal wear or seizing. Re-

move any burrs with sandpaper.

•

Remove adhesive from screw holes that use adhesive

through the tap. Do not reuse mounting bolts or

screws.

•

Do not use cloth gloves during assembly. Fibers from

the gloves could fall off and clog valves, etc., which

could cause parts to become faulty.

•

During assembly, be sure to apply clean hydraulic oil

to all moving parts in and sliding parts that come into

contact with the hydraulic motor and valve parts be-

fore installing or attaching the part.

•

Plug all ports once assembly has been completed in

order to prevent dust and dirt from entering.

•

Do not attempt to adjust the adjusting screws at times

other than when necessary.

CONTROL VALVE

4J0AS00

DISASSEMBLY AND ASSEMBLY

CONTROL VALVE

Disassembly

1. Remove the main relief valves P1, P2 (1) and the

main relief valve Pr (2) and then remove the O-rings

from the valves.

Valve (1): 78 N·m to 88 N·m

Valve (2): 49 N·m to 59 N·m

2. Remove the relief valves [Negative control] (3) and

then remove the O-rings from the valves.

Valve: 103 N·m to 113 N·m

3. Remove the port relief valves (4) and then remove

the O-rings from the valves.

• Do not disassemble the relief valves unless abso-

lutely necessary.

N0D230

Valve (1): 78 N·m to 88 N·m

4. Take out the plug (6), and remove the spring (7) and

poppet (8).

Plug: 103 N·m to 113 N·m

N0D231

5. Disassemble the travel section and travel forward

section.

a. Take out the plug (6), and remove the spring (7)

and poppet (8).

Plug: 103 N·m to 113 N·m

N0D232

CONTROL VALVE

4J0AS00

DISASSEMBLY AND ASSEMBLY

CONTROL VALVE

Take out the cap screws, and remove the covers

(11) and (12).

Cap screws: 20 N·m to 25 N·m

Remove the O-rings from the housing.

Remove the spool assemblies (11) and (12).

Take out the cap screws, and remove the covers

(13) and (14).

Cap screws: 20 N·m to 25 N·m

Remove the O-rings from the housing.

N0D233

Take out the cap screws (44), and remove the

spool.

• In order to keep the spool from becoming dam-

aged, secure it in place between two plates.

• Loctite compound has been applied to the

screw threads. Heat the screws to about 200°C

(392°F) to loosen the compound in order to re-

move the screws.

Cap screws: 9.8 N·m to 11.8 N·m

Remove the spring holder (45), and take out the

spring (46) and spring holder (45).

N0D245

6. Disassemble the 1st auxiliary line section and travel

1716

section.

a. Take out the plug (15), and remove the spring (16)

and poppet (17).

Plug: 103 N·m to 113 N·m

b. Take out the plug (6), and remove the spring (7)

and poppet (18).

Plug: 103 N·m to 113 N·m

N0D234

c. Remove the covers (9) and (13), and take out the

spools (19) and (20).

“Disassembling the travel and forward travel

sections”

N0D235

CONTROL VALVE

4J0AS00

DISASSEMBLY AND ASSEMBLY

CONTROL VALVE

7. Disassemble the slew and bucket sections.

a. Take out the plug (6), and remove the spring (7)

and poppet (8).

Plug: 103 N·m to 113 N·m

N0D236

b. Remove the covers (9) and (13), and take out the

spools (21) and (22).

“Disassembling the travel and forward travel

sections”

N0D237

8. Disassemble the boom 1 and boom 2 sections.

a. Take out the cap screws, and remove the anti-drift

valve (23).

Cap screws: 20 N·m to 25 N·m

b. Take out the spacer (24), and remove the O-ring

and backup ring from the spacer (24).

• Insert a bolt (M6×1.0) into the screw hole on the

spacer and tighten it all the way down as far as

it will go and then grip the bolt with fingers and

remove it.

c. Remove the spring (25) and the poppet (26).

d. Take out the plug (6), and remove the spring (7)

2625 24

N0D238

and poppet (8).

Plug: 103 N·m to 113 N·m

e. Remove the covers (9) and (13), and take out the

spools (27) and (28).

“Disassembling the travel and forward travel

sections”

N0D239

CONTROL VALVE

4J0AS00

DISASSEMBLY AND ASSEMBLY

CONTROL VALVE

9. Disassemble the arm 1 and arm 2 sections.

26 25 24

a. Remove the anti-drift valve (23), and take out the

spacer (24), spring (25), and poppet (26).

“Disassembling the boom 1 and boom 2 sec-

tions”

N0D240

b. Take out the plug (6), and remove the spring (7)

and poppet (8).

Plug: 103 N·m to 113 N·m

c. Take out the cap screws, and remove the flange

(29).

Cap screws: 39 N·m to 44 N·m

d. Remove the O-rings from the housing.

e. Take out the sleeve (30), and remove the springs

(31) and (32).

f. Remove the poppets (33) and (34).

N0D241

g. Remove the covers (9) and (13), and take out the

spools (35) and (36).

“Disassembling the travel and forward travel

sections”

N0D242

10. Take out the plug (37), and remove the O-ring from

39 38

the plug.

Plug: 103 N·m to 113 N·m

11. Remove the spring (38) and spool (39).

12. Remove the sleeve (40) and the piston (41).

13. Remove the O-rings and backup rings from the

sleeve (40).

N0D243

CONTROL VALVE

4J0AS00

DISASSEMBLY AND ASSEMBLY

CONTROL VALVE

14. Take out the cap screws, and remove the cover.

15. Remove the O-rings from the housing.

16. Remove the spool assembly (43).

N0D244

17. Disassemble the spool.

• In order to keep the spool from becoming dam-

aged, secure it in place between two plates.

• Loctite compound has been applied to the screw

threads. Heat the screws to about 200°C (392°F)

to loosen the compound in order to remove the

screws.

a. Remove the screws (47), and take out the spool.

b. Remove the spring holder (48), and take out the

spring (49) and spring holder (48).

N0D246

18. Take out the cap screws, and remove the cover (20).

Cap screws: 8.8 N·m to 10.8 N·m

19. Remove the O-rings from the housing.

20. Remove the spool assembly (51).

21. Disassemble the spool.

“17. Disassemble the spool.”

N0D247

22. Take out the plug (52), and remove the spring (53)

and poppet (54).

Plug: 73 N·m to 79 N·m

N0D248

CONTROL VALVE

4J0AS00

DISASSEMBLY AND ASSEMBLY

CONTROL VALVE

Add-on sections (Swing, blade, auxiliary lines)

1. Take out the nuts (1) and (2), and remove the speci-

fied sections.

Nut (1): 145 N·m to 159 N·m

Nut (1): 89 N·m to 97 N·m

N0D249

2. Take out the plug (3), and remove the spring (4) and

poppet (5).

Plug: 103 N·m to 113 N·m

N0D250

3. Take out the cap screws, and remove the cover (6).

Cap screws: 20 N·m to 25 N·m

4. Remove the O-rings from the housing.

5. Remove the spool assembly.

N0D251

6. Take out the cap screws, and remove the cover (8).

Cap screws: 20 N·m to 25 N·m

N0D252

CONTROL VALVE

4J0AS00

DISASSEMBLY AND ASSEMBLY

CONTROL VALVE

Anti-drift valve

1. Take out the plug (1), and remove the O-ring.

Plug: 147 N·m to 157 N·m

2. Remove the piston (2), spool (3), and spring (4).

N0D254

3. Take out the plug, and remove the O-ring.

Plug: 147 N·m to 157 N·m

4. Take out the sleeve (6), and remove the O-rings (8)

and (9) and backup rings (10) and (11) from the

911

sleeve (6).

• Make sure to attach the O-rings and backup rings

in the proper places during assembly. Failure to

do so may cause the boom to drop.

5. Remove the poppet (7), spring seat (12), and spring

(13).

N0D255

CONTROL VALVE

4J0AS00

DISASSEMBLY AND ASSEMBLY

CONTROL VALVE

Main relief valves

1. Remove the plug assembly (1), sleeve (2), spring (3),

and main poppet (4).

• The pilot seating is caulked to the end of the plug

and thus cannot be disassembled.

2. Take out the lock nut (5), and remove the washer (6)

and set screw (7) from the plug assembly.

• During assembly, after adjusting the set screw,

tighten the lock nut all the way down as far as it

can be.

3. Remove the spring (8) and valve (9) from the plug as-

sembly (1).

4. Remove the O-ring (10), backup ring (11), and O-

ring (12) from the plug assembly (1).

Assembly

For assembly, refer to the construction diagram and re-

verse the disassembly procedure.

CONTROL VALVE

4J0AS00

DISASSEMBLY AND ASSEMBLY

CONTROL VALVE

Inspection and adjustments

Inspection

Part

Criteria

Action

Housing,

•

If there are scratches, rust, or corrosion present on the parts that

•

Replace

Valve body

make sliding contact with the spool

•

If there are scratches, rust, or corrosion present on the seal pockets

•

Replace

of sections into which the spool enters

•

If there are scratches, rust, or corrosion of the seal part of the port in

•

Replace

contact with the O-ring

•

If there are scratches, rust, or corrosion in the seal part of the relief

•

Replace

valve, etc.

•

If there is other damage present that is thought to impair normal op-

•

Replace

eration of the machine

Spool

•

If there is scratching on the outer sliding surfaces that are rough

•

Replace

enough to be caught on a fingernail

•

If there is scratching on sliding surfaces on the end seals

•

Replace

•

If the spool does not move smoothly enough

•

Repair or replace

Load check

•

Repair or replace

•

If the sealing is faulty due to breakdown of the valve or spring

valve

•

If insertion and movement within the housing moves smoothly without

•

Normal

any parts becoming caught

Spring and re-

•

If there is noticeable rust, corrosion, deformation, or breakage of the

•

Replace

lated parts,

springs, holder, or cover

sections

Spool seals and

•

If there is leakage to external

•

Repair or replace

related parts,

•

If there is rust, corrosion, or deformation in the seal holder

•

Repair or replace

sections

Main relief

•

If there is rust or damage on the external surfaces of the parts

•

Replace

valves, port re-

•

If there is damage on surfaces that make contact with the valve

•

Replace

lief valves, anti-

seating

cavitation valve

•

If there is damage on surfaces that make contact with the poppet

•

Replace

•

If the spring is damaged or otherwise abnormal

•

Replace

•

For O-rings, backup rings, and seals

•

Replace after disassem-

bly as a general rule

Adjustment

Adjusting the main relief valve pressure

“2. Service data, Performance criteria”

CONTROL VALVE

4J0AS00

DISASSEMBLY AND ASSEMBLY

PILOT VALVE

Special tools

Figures in diagrams are given in mm.

Installation jig A

Quantity: 1

Material A: S45C

Material B: SCM415N (Carburizing hardening)

Installation jig B

Quantity: 2

Material B: SCM415N (Carburizing hardening)

Disassembly and assembly

The numbers in parentheses, (), listed after the names of

parts throughout this document are used to refer to the

same parts as the numbers listed in the construction di-

agram and parts lists.

General precautions

•

Perform disassembly and assembly work in a clean

place. Provide clean containers to hold parts during

disassembly.

•

Clean around the ports before disassembly. Remove

paint around connectors with a wire brush.

•

Clean the disassembled parts with wash oil.

•

Put alignment marks on all parts to ensure that they are

reassembled in the same positions.

•

After each disassembly, replace all seals and apply a

thin layer of grease to each.

•

Check each part for abnormal wear or seizing. Re-

move any burrs with sandpaper.

•

Remove adhesive from screw holes that use adhesive

through the tap. Do not reuse mounting bolts or

screws.

•

Do not use cloth gloves during assembly. Fibers from

the gloves could fall off and clog valves, etc., which

could cause parts to become faulty.

•

During assembly, be sure to apply clean hydraulic oil

to all moving parts in and sliding parts that come into

contact with the hydraulic motor and valve parts be-

fore installing or attaching the part.

•

Plug all ports once assembly has been completed in

order to prevent dust and dirt from entering.

•

Do not attempt to adjust the adjusting screws at times

other than when necessary.

PILOT VALVE

4K2AS00

DISASSEMBLY AND ASSEMBLY

PILOT VALVE

Disassembly

1. Disconnect the electrical wiring from the handle (21).

2. Remove the boot (23) and the handle (21).

3. Take out the nut (18), and remove the plate (17).

• Place the valve in a vice and secure it using a

copper or lead plate.

4. Take out the joint (16), and remove the plate (9).

• Use the installation jigs A and B.

• Take care as the plugs (10) may start to come out.

5. Remove the plugs (10) from the casing (24), and re-

move the rods (11) from the plugs (10).

• Use a flat-bladed screwdriver to remove the plugs

if they cannot be pried out by hand.

• Take care as the plugs may pop out due to spring

pressure.

PILOT VALVE

4K2AS00

DISASSEMBLY AND ASSEMBLY

PILOT VALVE

6. Remove the seals (3) and O-rings (4) from the plugs

(10).

7. Remove the reducing valves and the springs (14)

from the casing (24).

• Keep a record to indicate which hole on the cas-

ing (24) that the reducing valves came out of to

ensure that each valve can be returned to its

same hole during reassembly.

8. Disassemble the reducing valve.

a. Push in the holder (12) to compress the spring

(15) in order to move the spool (25) from the small

hole side to the large hole side of the holder (12).

• The holder is not to be pushed down by more

than 6 mm (0.24 in.).

b. Remove the holder (12), spring (15), and washer

(13) from the spool (25).

PILOT VALVE

4K2AS00

DISASSEMBLY AND ASSEMBLY

PILOT VALVE

Assembly

1. Attach the bushing (8) and O-ring to the casing (24).

2. Use the cap screws (6) and washers (1) to attach the

plate (5) to the casing (24).

• Make sure to replace the old washers with new

ones as they cannot be reused.

Cap screw: 20.6 N·m ± 1.5 N·m

3. Assemble the reducing valve.

a. Attach the washer (13), spring (15), and holder

(12) to the spool (25).

b. Push in the holder (12) to compress the spring

(15) in order to move the spool (25) from the large

hole side to the small hole side of the holder (12).

• The holder is not to be pushed down by more

than 6 mm (0.24 in.).

PILOT VALVE

4K2AS00

DISASSEMBLY AND ASSEMBLY

PILOT VALVE

4. Insert each of the springs (16) and reducing valves

back into the same holes on the casing from which

they were removed before disassembly.

5. Attach the O-ring (4) and seal (3) to the plug (10).

6. Attach the rods (11) to the plugs (10).

• Apply lubricating oil to the rods.

7. After inserting the plugs (10) and attaching the plate

(17), attach the joint (16).

• Use the installation jigs A and B to attach the joint.

Joint: 47.1 N·m ± 2.9 N·m

PILOT VALVE

4K2AS00

Takeuchi Hydraulic excavator TB1140 (Serial No. 514400002~). Operator's Manual - page 6