JCB 3CX, 4CX, 214e, 214, 215, 217 & VARIANTS Backhoe Loader. Service Manual

Section E

Hydraulics

Section E

50 - 15

Loader Valve - Fixed Flow

50 - 15

Dismantling and Assembly

Assembly

Float Spool - Manual

Fit the boot 2 to the seal plate 3.

The numerical sequence shown on the illustration is intended

as a guide to dismantling.

Fit a new lipseal 5 into the valve block, ensure square.

Fit wiper 4 on top of lipseal.

For assembly the sequence should be reversed.

Fit the seal plate and boot assembly to valve block but

The following points MUST be avoided when dismantling

do not torque tighten capscrews 1 at this stage. Ensure

wiper locates into seal plate.

and assembling the valve:

Use clean hydraulic oil as a lubricant. From the bottom,

•

CONTAMINATION

insert spool through the valve block, do not use

•

DAMAGE TO SPOOL

excessive force when fitting, a turning motion should

•

DAMAGE TO SEAL GROOVES

ease the spool through the valve block.

All or any of the above points may result in possible

Check that the tang end of the spool passes through

problems with the valve.

the boot without dislodging or damaging the boot.

Ensure that the tang aligns with the control rod and

Dismantling

that the boot is not distorted and is located in the spool

Remove the lever linkage from the tang (lever) end of the

land.

spool.

Torque tighten cap screws 1.

When removing 'O' rings and seals, use an appropriately

When fitting detent pin 20, clean the threads thoroughly

rounded tool that WILL NOT cause any damage to the spool

using JCB Cleaner/Degreaser, leave it for 10 minutes

or seal grooves, for instance, item 4, which is a wiper seal

then apply a small quantity of JCB Threadlocker and

and is a press fit in the counterbore.

Sealer to the threads of the spool.

Care must be taken to ensure that the spool 13 is not

Apply grease liberally balls 10, this will help to hold the

damaged when removing it from the valve block.

balls in position whilst assembling.

Carefully remove collar 9 and collect detent balls 10.

Renew 'O' ring 15. Make sure the 'O' ring is not

trapped or damaged.

Using tool 992/10100 to hold the spool, remove circlip 16,

plug 17, ball 18 and spring 19. Unscrew detent pin 20 and

Fit seal 15 and seal plate 14 to the valve block section.

remove spring 22 and cups 21 and 23.

Torque tighten capscrew 6 on completion.

Check for surface contamination on the under side of the

Re-connect the lever mechanism to the tang (lever) end of

seal plates 3 and 14. Clean if necessary. Check for the

the spool.

flatness of the seal plate. If found to be bent - replace with

new (any work previously carried out on this valve may have

Run the engine and inspect the valve for external leaks.

resulted in the bending of the seal plate).

Torque Settings

Item

kgf m

lbf ft

9.5

0.96

9.5

0.96

9.5

0.96

9803/3280

Issue 1

Section E

Hydraulics

Section E

50 - 17

Loader Valve - Fixed Flow

50 - 17

Dismantling and Assembly

Electric Detent Spool - Manual

Assembly

The numerical sequence shown on the illustration is intended

as a guide to dismantling.

Fit the boot 1A to the seal plate 2.

For assembly the sequence should be reversed.

Fit a new lipseal 4 into the valve block, ensure square.

The following points MUST be avoided when dismantling

Fit wiper 3 on top of lipseal.

and assembling the valve:

Fit the seal plate and boot assembly to valve block but

•

CONTAMINATION

do not torque tighten capscrews 1 at this stage. Ensure

•

DAMAGE TO SPOOL

wiper locates into seal plate.

•

DAMAGE TO SEAL GROOVES

Use clean hydraulic oil as a lubricant. From the bottom,

All or any of the above points may result in possible

insert spool through the valve block, do not use

problems with the valve.

excessive force when fitting, a turning motion should

ease the spool through the valve block.

Dismantling

Check that the tang end of the spool passes through

When removing 'O' rings and seals, use an appropriately

the boot without dislodging or damaging the boot.

Ensure that the tang aligns with the control rod and

rounded tool that WILL NOT cause any damage to the spool

that the boot is not distorted and is located in the spool

or seal grooves, for instance, item 3, which is a wiper seal

land.

and is a press fit in the counterbore.

Torque tighten cap screws 1.

Care must be taken to ensure that the spool 12 is not

damaged when removing it from the valve block.

When fitting spool end 15, clean the threads thoroughly

using JCB Cleaner/Degreaser, leave it for 10 minutes

Use tool 992/10100 to hold the spool, remove circlip 13 and

then apply a small quantity of JCB Threadlocker and

'clapper' 14. Unscrew spool end 15 and remove spring 17

Sealer to the threads of the spool.

with cups 16 and 18.

Make sure that the chamfer on item 14 faces away from

Check for surface contamination on the under side of the

the solenoid, item 6.

seal plates 2, 8 and 10. Clean if necessary. Check for the

flatness of the seal plate. If found to be bent - replace with

Renew lipseal 11. Make sure the lipseal is not trapped

new (any work previously carried out on this valve may have

or damaged.

resulted in the bending of the seal plate).

Fit lipseal 11 and seal plate 10 to the valve block

section. Torque tighten capscrew 5 on completion.

Check the operation of the solenoid 6 after assembly by

connecting a 12V supply. The spool should be held when it

is pushed into the detent position and returned when the

supply is disconnected.

Run the engine and inspect the valve for external leaks.

Torque Settings

Item

kgf m

lbf ft

9.5

0.96

9.5

0.96

9.5

0.96

9803/3280

Issue 1

Section E

Hydraulics

Section E

50 - 25

Loader Valve - Fixed Flow

50 - 25

Dismantling and Assembly

Bolt on Auxiliary Spool Section

Body and Spool

The numerical sequence shown on the illustration is intended

Torque Settings

as a guide to dismantling.

Item

kgf m

lbf ft

Two dismantling sequences are shown:

1.9

Components prefixed A - inlet section, valve body and non-

4.6

return valve.

1B, 3B

8 - 11

0.8 - 1.1

6 - 8

Components prefixed B - valve spool components.

40 - 49

4 - 5

30 - 36

The valve spool components can be dismantled and

assembled with the valve body 5A still assembled to the

loader valve E if required.

For assembly the sequence should be reversed.

The following points MUST be avoided when dismantling

and assembling the valve:

• CONTAMINATION

• DAMAGE TO SPOOL

• DAMAGE TO SEAL GROOVES

All or any of the above points may result in possible

problems with the valve.

For dismantling and assembly of the auxiliary relief valves

1C, see Bolt on Auxiliary Spool Section - Auxiliary Relief

Valves.

When Dismantling

When removing 'O' rings and seals, use an appropriately

rounded tool that WILL NOT cause any damage to the spool

or seal grooves.

When dismantling the spool hold a rod through the eye end

of the spool to prevent it rotating when undoing the screw at

the opposite end.

Inspection

Inspect the valve components for signs of scratches, nicks

or any other type of damage. Renew damaged components

as required.

When Assembling

Renew 'O' ring seals 4A, 8A, and 2C. Make sure the 'O' ring

seals are not trapped or damaged.

Renew wiper seals 8B and 11B, and spool seals 9B and

12B, note the correct seal orientation shown at X. When

fitting seals 9B and 12B make sure they are square to the

valve body.

9803/3280

Issue 1

Section E

Hydraulics

Section E

50 - 27

Loader Valve - Fixed Flow

50 - 27

Dismantling and Assembly

Bolt on Auxiliary Spool Section

Auxiliary Relief Valve (ARV)

The numerical sequence shown on the illustration is

intended as a guide to dismantling.

For assembly the sequence should be reversed.

Great care should be taken when dismantling and

assembling a valve to avoid the following:-

Contamination

Damage to spools

Damage to seal grooves

Any of the above may result in possible problems with the

operation of the valve.

When Dismantling

When removing 'O' Rings and seals, use an appropriatly

rounded tool that WILL NOT cause any damage to the seal

grooves.

Discard ALL 'O' Rings and back-up rings. DO NOT use

worn or damaged items.

Inspection

Inspect the valve components for scratches, nicks or any

other type of damage, replace with new if required.

When Assembling

Renew all 'O' rings and back-up rings.

Lubricate parts with JCB Hydraulic Fluid before assembling.

Make sure that all the parts move freely.

Make sure that the ‘O’ rings and back-up rings are fitted the

correct way, items 13, 14 and 19, 20.

Adjust pressure setting as required, refer to Service

Procedures, Pressure Testing - MRV and ARV’s.

Torque Settings

Item

kgf m

lbf ft

6.4

5.4 - 8.2

0.55 - 0.83

4 - 6

41 - 68

4.15 - 6.9

30 - 50

9803/3280

Issue 1

Section E

Hydraulics

Section E

51 - 2

Loader Valve - Fixed Flow

51 - 2

Dismantling and Assembly

Precision Control (Servo)

(Machines from January 2003)

Dismantling

The loader valve block is a ‘sandwich type’, which is made

Service Spools

Care must be taken to ensure that the spools 6 are not

up of a number of separate sections. The illustration shown

on the opposite page is intended as a guide to dismantling.

damaged when removing them from the block. Note that all

Be sure to note the location of all components when

spools may be similar in appearance but must not be

dismantling. Although some components may appear to be

interchanged as they are matched to their bores.

identical they are not interchangeable. Make sure that

Standard Spool

components are assembled in their original positions.

The dismantling and assembly procedures for the standard

Remove the loader valve block from the machine.

spool assembly 7 are detailed separately, refer to Standard

Spool.

Remove the three tie rod nuts 1.

Electric Detent Spool

Carefully separate and remove the end plate 2 followed

The dismantling and assembly procedures for the electric

by the remaining service sections 3. If the inlet section 4

detent spool assembly 8 are detailed separately, refer to

is to be replaced, remove and retain the tie rods 5.

Electric Detent Spool.

Mechanical Detent Spool

Assembly

The dismantling and assembly procedures for the

mechanical detent spool assembly 9 are detailed separately,

Assembly is the reverse of the dismantling sequence.

refer to Mechanical Detent Spool.

Clean the valve components in an appropriate solvent.

Auxiliary Relief Valves

Ensure that the mating faces of the valve sections are

The A.R.V's 10 appear identical but have various pressure

thoroughly clean before assembly.

settings, refer to Technical Data. Ensure that they are

correctly adjusted and fitted in their specified positions.

Renew the ‘O’ rings located between the valve sections.

The dismantling and assembly procedures for the ARV’s are

Make sure the ‘O’ ring seals are not trapped or

detailed separately, refer to Excavator Valve, Dismantling

damaged.

and Assembly - Auxiliary Relief Valves (ARV’s).

Lubricate parts with JCB Hydraulic Fluid before

Pressure Compensator Valves

assembling. Make sure that all the parts move freely.

Each of the pressure compensator valves 11 can be

removed as shown. Note that all valves are identical in

Torque Settings

appearance. Note that components are not interchangeable.

Item

kgf m

lbf ft

Load Hold Check Valves

3.6

25.8

Each of the load hold check valves 12 can be removed as

7.4

shown. Note that all valves are identical in appearance.

7.4

Ensure good condition of seating faces on poppets and on

7.4

the mating faces in the valve block.

7.4

14.8

7.4

7.1

51.6

10A

7.1

51.6

6.1

44.3

22.1

9803/3280

Issue 1

Section E

Hydraulics

Section E

51 - 4

Loader Valve - Fixed Flow

51 - 4

Dismantling and Assembly

Precision Control (Servo)

(Machines from January 2003)

Standard Spool

Removal

Inspection

It is possible to remove a spool without removing the loader

Inspect the valve components for scratches, pitting,

valve block from the machine. The centring spring 11 is at

corrosion or any other type of damage.

the bottom, so the spool must be removed from the bottom.

Assembly

Gain access to the loader valve and disconnect and

blank any hoses or pipes which may interfere with the

Assembly is the reverse of the dismantling sequence.

removal of the spool.

Clean the valve components in an appropriate solvent.

Disconnect the control rod linkage from the spool

tongue.

Lubricate parts with JCB Hydraulic Fluid before

assembling. Make sure that all the parts move freely.

Remove the screws 1, boot 2 and plate 3.

Renew lip seals 4 and 14, and 'O' rings 5 and 15.

Remove the screws 6, cover 7 and carefully withdraw

the spool assembly from the valve body.

Note: The lip seal MUST be fitted carefully onto the end of

the spool to ensure that it is not damaged by the spool lands

Dismantling

and that its tightness property does not deteriate. The metal

part of the seal should be on the outside.

Great care should be taken when dismantling and

assembling a valve to avoid the following:-

Torque Settings

• Contamination

Item

kgf m

lbf ft

7.4

• Damage to spools

7.4

• Damage to seal grooves

7.4

Any of the above may result in possible problems with the

operation of the valve.

Hold the spool assembly in a vice using the spool clamp

(service tool no. TBA, refer to Service Tools) as shown

at A.

Tongue Replacement (if necessary)

Unscrew the spool end 9 and remove the centring

Hold the spool assembly in a vice using the spool clamp

spring 11 with spring retainers 10 and 12. It may be

(service tool no. TBA, refer to Service Tools).

necessary to pre-heat the spool to 200° C in an oven or

with a heat gun to remove the spool end.

Loosen the tongue 16 with an open ended wrench as

shown at B. It may be necessary to pre-heat the spool

Note: When removing 'O' Rings and seals, use an

to 200° C in an oven or with a heat gun to dismantle the

appropriatly rounded tool that WILL NOT cause any damage

spool.

to the seal grooves.

Note: DO NOT use a welding torch to heat the tongue as

Discard ALL 'O' Rings and back-up rings. DO NOT use worn

deformation of the spool may result.

or damaged items.

9803/3280

Issue 1

Section E

Hydraulics

Section E

51 - 6

Loader Valve - Fixed Flow

51 - 6

Dismantling and Assembly

Precision Control (Servo)

(Machines from January 2003)

Electric Detent Spool

Removal

Inspection

It is possible to remove a spool without removing the loader

Inspect the valve components for scratches, pitting,

valve block from the machine. The centring spring 15 is at

corrosion or any other type of damage.

the bottom, so the spool must be removed from the bottom.

Assembly

Gain access to the loader valve and disconnect and

blank any hoses or pipes which may interfere with the

Assembly is the reverse of the dismantling sequence.

removal of the spool.

Clean the valve components in an appropriate solvent.

Disconnect the control rod linkage from the spool

tongue.

Lubricate parts with JCB Hydraulic Fluid before

assembling. Make sure that all the parts move freely.

Remove the screws 1, boot 2 and plate 3.

Renew lip seal 4 and 'O' rings 5 and 18.

Unscrew the solenoid 6 from the housing 8. Remove the

screws 7, housing 8 and carefully withdraw the spool

Note: The lip seal MUST be fitted carefully onto the end of

assembly from the valve body.

the spool to ensure that it is not damaged by the spool lands

and that its tightness property does not deteriate. The metal

Dismantling

part of the seal should be on the outside.

Great care should be taken when dismantling and

Torque Settings

assembling a valve to avoid the following:-

Item

kgf m

lbf ft

• Contamination

7.4

• Damage to spools

7.4

• Damage to seal grooves

7.4

Any of the above may result in possible problems with the

operation of the valve.

Hold the spool assembly in a vice using the spool clamp

(service tool no. TBA, refer to Service Tools) as shown

at A.

Remove the circlip 10, disc 11 and spring 12.

Tongue Replacement (if necessary)

Unscrew the spool end 13 and remove the centring

Hold the spool assembly in a vice using the spool clamp

spring 15 with spring retainers 14 and 16. It may be

(service tool no. TBA, refer to Service Tools).

necessary to pre-heat the spool to 200° C in an oven or

with a heat gun to remove the spool end.

Loosen the tongue 19 with an open ended wrench as

shown at B. It may be necessary to pre-heat the spool

Note: When removing 'O' Rings and seals, use an

to 200° C in an oven or with a heat gun to dismantle the

appropriatly rounded tool that WILL NOT cause any damage

spool.

to the seal grooves.

Note: DO NOT use a welding torch to heat the tongue as

Discard ALL 'O' Rings and back-up rings. DO NOT use worn

deformation of the spool may result.

or damaged items.

9803/3280

Issue 1

Section E

Hydraulics

Section E

51 - 8

Loader Valve - Fixed Flow

51 - 8

Dismantling and Assembly

Precision Control (Servo)

(Machines from January 2003)

Mechanical Detent Spool

Removal

Inspection

It is possible to remove a spool without removing the loader

Inspect the valve components for scratches, pitting,

valve block from the machine. The centring spring 16 is at

corrosion or any other type of damage.

the bottom, so the spool must be removed from the bottom.

Assembly

Gain access to the loader valve and disconnect and

blank any hoses or pipes which may interfere with the

Assembly is the reverse of the dismantling sequence.

removal of the spool.

Clean the valve components in an appropriate solvent.

Disconnect the control rod linkage from the spool

tongue.

Lubricate parts with JCB Hydraulic Fluid before

assembling. Make sure that all the parts move freely.

Remove the screws 1, boot 2 and plate 3.

Renew lip seal 4 and 'O' rings 5, 19 and 20.

Remove the screws 6, cover 7 and carefully withdraw

the spool assembly from the valve body.

Note: The lip seal MUST be fitted carefully onto the end of

the spool to ensure that it is not damaged by the spool lands

Dismantling

and that its tightness property does not deteriate. The metal

part of the seal should be on the outside.

Great care should be taken when dismantling and

assembling a valve to avoid the following:-

Torque Settings

• Contamination

Item

kgf m

lbf ft

7.4

• Damage to spools

7.4

• Damage to seal grooves

7.4

Any of the above may result in possible problems with the

operation of the valve.

Hold the spool assembly in a vice using the spool clamp

(service tool no. TBA, refer to Service Tools) as shown

at A.

Use a metal rod (min. length 80 mm x 6 mm diameter)

to push on the central ball 10 whilst extracting the

detent bush 9 as shown. Mark the orientation of the

bush to ensure that it is fitted the correct way round on

re-assembly.

Carefully remove the balls 10 and 12, and the spring 11.

Tongue Replacement (if necessary)

Unscrew the spool end 13 and remove the centring

Hold the spool assembly in a vice using the spool clamp

spring 16 with spring retainers 15 and 17. It may be

(service tool no. TBA, refer to Service Tools).

necessary to pre-heat the spool to 200° C in an oven or

with a heat gun to remove the spool end.

Loosen the tongue 16 with an open ended wrench as

shown at B. It may be necessary to pre-heat the spool

Note: When removing 'O' Rings and seals, use an

to 200° C in an oven or with a heat gun to dismantle the

appropriatly rounded tool that WILL NOT cause any damage

spool.

to the seal grooves.

Note: DO NOT use a welding torch to heat the tongue as

Discard ALL 'O' Rings and back-up rings. DO NOT use worn

deformation of the spool may result.

or damaged items.

9803/3280

Issue 1

Section E

Hydraulics

Section E

55 - 1

Loader Valve - Variable Flow

55 - 1

Removal and Replacement

Replacement

! WARNING

Make the machine safe before working underneath it.

Replacement is a reversal of the removal sequence.

Park the machine on level ground, lower the arms. Apply

the parking brake, put the transmission in neutral and

! WARNING

stop the engine. Chock both sides of all four wheels.

Fine jets of hydraulic fluid at high pressure can penetrate

the skin. Do not use your fingers to check for hydraulic

Disconnect the battery, to prevent the engine being

fluid leaks. Do not put your face close to suspected

started while you are beneath the machine.

GEN-1-2

leaks. Hold a piece of cardboard close to suspected

leaks and then inspect the cardboard for signs of

hydraulic fluid. If hydraulic fluid penetrates your skin, get

! DANGER

medical help immediately.

Hydraulic Pressure

INT-3-1-10/1

Hydraulic fluid at system pressure can injure you. Before

disconnecting or connecting hydraulic hoses, stop the

After replacement check the auxiliary relief valve (A.R.V.)

engine and operate the controls to release pressure

pressure settings.

trapped in the hoses. Make sure the engine cannot be

started while the hoses are open.

Note: All hydraulic adapters that are installed together with a

INT-3-1-11/1

bonded sealing washer must also have sealant (JCB

Threadseal) applied to the threads of the adapter.

Removal

Operate the valve block levers back and forth to vent

residual pressure.

Remove clevis pins A to disconnect the control levers

from the valve block spools.

Disconnect all hydraulic hoses from the valve block and

plug all orifices to prevent ingress of dirt. Label each

hose before disconnecting, this will ensure correct

position when refitting.

Loosen and remove nuts B, spacers C, the loader valve

and resilient mounts D.

Inspection

Inspect the resilient mounts D for damage, cracking etc. If

the mounts are suspect, then replace them with new ones.

C D

S273910

9803/3280

Issue 1

Section E

Hydraulics

Section E

55 - 3

Loader Valve - Variable Flow

55 - 3

Dismantling and Assembly

Assembly

Priority Inlet Section

Renew all 'O' rings and back-up rings.

The numerical sequence shown on the illustration is

intended as a guide to dismantling.

Lubricate parts with JCB Hydraulic Fluid before assembling.

Make sure that all the parts move freely.

For assembly the sequence should be reversed.

Make sure that the 'O' rings and back-up rings are fitted the

The following points MUST be avoided when dismantling

correct way, items 11 and 12

and assembling the valve:

ALWAYS fit three shim (item 5) in between each valve block

•

CONTAMINATION

section as shown.

•

DAMAGE TO SPOOL

•

DAMAGE TO SEAL GROOVES

After assembly, make sure the steering operates correctly.

The steer circuit will always have priority (see descriptions).

All or any of the above points may result in possible

problems with the valve.

Torque Settings

Dismantling

Item

kgf m

lbf ft

4.1

Remove tie rod nuts 1 and end cover 2. Separate the valve

6.9

sections 3 take care not to lose shims 5. Remove and

discard ‘O’ rings 4.

6.9

13.5

1.38

When removing 'O' rings and seals, use an appropriately

Item

Description

rounded tool that WILL NOT cause any damage to the seal

Tie rod nuts

grooves.

End cover

Valve section

Discard ALL 'O' rings and back up rings. DO NOT use worn

O-ring

or damaged items.

Shim

Tie rod

Inspect the valve components for scratches, nicks or any

other type of damage, replace with new if required.

Plug

O-ring

Relief valve assembly

Inspect screen A, make sure the screen is clean and free of

O-ring

dirt.

O-ring

Take care not to lose ball bearing 17.

Back-up ring

Spring

Spool

If required, the relief valve assembly 9 can be dismantled for

Expansion plug

cleaning. It is important to note that this relief valve is fitted

Shuttle plug assembly

as a standard part of the inlet section. However, in this

application it does not perform any duties. This is because

Ball bearing

Adjusting Screw

the steer system pressure is controlled by a relief valve in

the orbitrol steer unit (see Steering section), NOT relief valve

assembly 9.

After assembling the relief valve, screw the adjusting screw

18 fully into the valve housing. This will ensure assembly 9

does not interfere with the steer system pressure.

9803/3280

Issue 1

Section E

Hydraulics

Section E

55 - 5

Loader Valve - Variable Flow

55 - 5

Dismantling and Assembly

Assembly

Auxiliary Spool

Renew all 'O' rings and back-up rings.

The numerical sequence shown on the illustration is

intended as a guide to dismantling.

When fitting bolt 14, clean the threads then apply a small

quantity of JCB Threadlocker & Sealer to the threads of the

For assembly the sequence should be reversed.

spool.

The following points MUST be avoided when dismantling

When fitting spool seals 19 and 20 refer to the procedure

and assembling the valve:

Fitting Spool Seal.

•

CONTAMINATION

ALWAYS fit three shim (item 5) in between each valve block

•

DAMAGE TO SPOOL

section as shown.

•

DAMAGE TO SEAL GROOVES

Run the engine and inspect the valve for external leaks.

All or any of the above points may result in possible

problems with the valve.

Torque Settings

Dismantling

Item

kgf m

lbf ft

4.1

Remove tie rod nuts 1 and end cover 2. Separate the valve

0.55

sections 3 take care not to lose shims 5. Remove and

discard ‘O’ rings 4.

0.8

6.9

When removing 'O' rings and seals, use an appropriately

13.5

1.38

rounded tool that WILL NOT cause any damage to the spool

13.5

1.38

or seal grooves.

Care must be taken to ensure that the spool 13 is not

Item

Description

damaged when removing it from the valve block.

Tie rod nuts

End cover

Hold the spool in a suitable clamp, unscrew bolt 14 and

remove spring 17, spacer 16 and cups 15 and 18.

Valve section

O-ring

Shim

Bolt

Dust boot

Dust guard

Seal

Bolt

Washer

Centering spring housing

Spool assembly

Bolt

Spring cup

Spacer

Spring

Spring cup

O-ring

Plug

O-ring

Spring

Poppet

Primary shuttle housing

Shuttle plug assembly

Ball bearing

9803/3280

Issue 1

Section E

Hydraulics

Section E

55 - 7

Loader Valve - Variable Flow

55 - 7

Dismantling and Assembly

Loader Shovel Spool

Torque Settings

The numerical sequence shown on the illustration is

Item

kgf m

lbf ft

intended as a guide to dismantling.

4.1

0.55

For assembly the sequence should be reversed.

0.8

2.7

0.27

The following points MUST be avoided when dismantling

1.1

and assembling the valve:

26, 30

6.9

•

CONTAMINATION

Item

Description

•

DAMAGE TO SPOOL

Tie rod nuts

•

DAMAGE TO SEAL GROOVES

End cover

Valve section

All or any of the above points may result in possible

O-ring

problems with the valve.

Shim

Bolt

Dismantling

Dust boot

Dust guard

Remove tie rod nuts 1 and end cover 2. Separate the valve

Seal

sections 3 take care not to lose shims 5. Remove and

discard ‘O’ rings 4.

Bolt

Washer

Detent Solenoid

When removing 'O' rings and seals, use an appropriately

Tube

rounded tool that WILL NOT cause any damage to the spool

Gasket

or seal grooves.

Capscrew

Washer

Place a suitable rod through the eye end of spool 21.

Armature Plate

Spring

Care must be taken to ensure that the spool 21 is not

Centering Spring Housing

damaged when removing it from the valve block.

O-ring

Spool

Hold the spool in a suitable clamp, Unscrew coupling 22 and

Coupling

remove spring 24 and cups 23 and 25.

Spring cup

Spring

Relief valve assembly 30 can be dismantled for cleaning

purposes only. Individual parts for the relief valve are not

Spring cup

Plug

available (except seal kits).

O-ring

Spring

Assembly

Poppet

Renew all 'O' rings and back-up rings.

Relief valve assembly

O ring

Back-up ring

Inspect gasket 14, replace with a new one if required.

O-ring

When fitting coupling 22, clean the threads then apply a

small quantity of JCB Threadlocker & Sealer to the threads

O-ring

Primary shuttle housing

of the spool.

Shuttle plug assembly

Ball bearing

Check the operation of the solenoid 12 after assembly by

connecting a 12V supply . The spool should be held when it

is pushed into the detent position and returned when the

supply is disconnected.

When fitting spool seals 34 and 35 refer to the procedure

Fitting Spool Seal.

ALWAYS fit three shim (item 5) in between each valve block

section as shown.

Run the engine and inspect the valve for external leaks.

9803/3280

Issue 1

Section E

Hydraulics

Section E

55 - 9

Loader Valve - Variable Flow

55 - 9

Dismantling and Assembly

Assembly

Loader Lift Spool

Renew all 'O' rings and back-up rings.

The numerical sequence shown on the illustration is

intended as a guide to dismantling.

When fitting coupling 20, clean the threads then apply a

small quantity of JCB Threadlocker & Sealer to the threads

For assembly the sequence should be reversed.

of the spool.

The following points MUST be avoided when dismantling

When fitting spool seals 26 and 27 refer to the procedure

and assembling the valve:

Fitting Spool Seal.

•

CONTAMINATION

ALWAYS fit three shim (item 5) in between each valve block

•

DAMAGE TO SPOOL

section as shown.

•

DAMAGE TO SEAL GROOVES

Run the engine and inspect the valve for external leaks.

All or any of the above points may result in possible

problems with the valve.

Torque Settings

Dismantling

Item

kgf m

lbf ft

4.1

Remove tie rod nuts 1 and end cover 2. Separate the valve

0.55

sections 3 take care not to lose shims 5. Remove and

discard ‘O’ rings 4.

0.8

13.5

1.38

When removing 'O' rings and seals, use an appropriately

13.5

1.38

rounded tool that WILL NOT cause any damage to the spool

6.9

or seal grooves.

Item

Description

Care must be taken to ensure that the spool 18 is not

Tie rod nuts

damaged when removing it from the valve block.

End cover

Valve section

Hold the spool in a suitable clamp, use a punch to separate

detent shaft 19 from coupling 20. Unscrew coupling 20 and

O-ring

Shim

remove spring 22, spacer 23 and cups 21 and 24.

Bolt

Dust boot

Use a suitable press to compress spring 14 and remove

Dust guard

retaining ring 12. Take care not to lose detent balls 16.

Seal

Capscrew

Detent housing

Retaining ring

Retainer

Spring

Piston

Detent balls

Washer

Spool assembly

Detent shaft

Pivot coupling

Spring cup

Spring

Spacer

Spring cup

O-ring

Primary shuttle housing

Shuttle plug assembly

Ball bearing

Plug

O-ring

Spring

Poppet

9803/3280

Issue 1

Section E

Hydraulics

Section E

55 - 10

Loader Valve - Variable Flow

55 - 10

Dismantling and Assembly

Fitting Spool Seal

Use the procedure described below to correctly install the

valve spool seals:

Lubricate the spool, bore and O-ring groove with JCB

Hydraulic Fluid. Move the spool to the position shown

and then install the O-ring A in its groove.

Move the spool to the position shown and then install

the O-ring B. It is important to note that the spool must

not be moved beyond the position shown, otherwise

the edge of the spool (face C) may damage the first

fitted O-ring (item A).

Position the spool in its central position as shown. Re-

assembe the centering assembly, dust boot etc as

detailed previously in this section.

A276280

9803/3280

Issue 1

Section E

Hydraulics

Section E

60 - 1

Excavator Valve

60 - 1

Removal and Replacement

! CAUTION

Manual Control

This component is heavy. Do not attempt to remove it

unless its weight is held by a sling. Make sure that the

! WARNING

sling is attached to a suitable lifting appliance.

Make the machine safe before working underneath it.

HYD 2-3/1

Park the machine on level ground, lower the arms. Apply

the parking brake, put the transmission in neutral and

Wrap a suitable sling around the valve, make sure that

stop the engine. Chock both sides of all four wheels.

the weight of the valve is supported by the sling.

Disconnect the battery, to prevent the engine being

Remove nuts B and lower the valve block to the

started while you are beneath the machine.

ground.

GEN-1-2

Replacement

! DANGER

Hydraulic fluid at system pressure can injure you. Before

Replacement is a reversal of the removal sequence.

disconnecting or connecting hydraulic hoses, stop the

engine and operate the controls to release pressure

Hoses and pipes (when applicable) must be re-connected

trapped in the hoses. Make sure the engine cannot be

and phased in same position as removal. Refer to

started while the hoses are open.

Dismantling and Assembly, Hoses and Pipes.

INT-3-1-11/1

! WARNING

Removal

Fine jets of hydraulic fluid at high pressure can

penetrate the skin. Do not use your fingers to check for

Operate the valve block levers back and forth to vent

hydraulic fluid leaks. Do not put your face close to

residual pressure.

suspected leaks. Hold a piece of cardboard close to

suspected leaks and then inspect the cardboard for

Remove the rear valance.

signs of hydraulic fluid. If hydraulic fluid penetrates your

skin, get medical help immediately.

Remove clevis pins A to disconnect the control levers

INT-3-1-10/1

from the valve block spools.

After replacement check the auxiliary relief valve (A.R.V.)

Disconnect all hydraulic hoses from the valve block and

pressure settings.

plug all orifices to prevent ingress of dirt. Label each

hose before disconnecting, this will ensure correct

Note: All hydraulic adapters that are installed together with

position when refitting.

a bonded sealing washer must also have JCB Threadseal

applied to the threads of the adapter.

Loosen nuts B - do not completely remove the retaining

nuts.

S401480

9803/3280

Issue 1

JCB 3CX, 4CX, 214e, 214, 215, 217 & VARIANTS Backhoe Loader. Service Manual - page 18