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

Section E

Hydraulics

Section E

60 - 5

Excavator Valve

60 - 5

Removal and Replacement

Inspection

Variable Flow

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

! WARNING

mounts are suspect, then replace them with new ones.

Make the machine safe before working underneath it.

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

Replacement

the parking brake, put the transmission in neutral and

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

Replacement is a reversal of the removal sequence.

Disconnect the battery, to prevent the engine being

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

started while you are beneath the machine.

GEN-1-2

and phased in same position as removal. Refer to

Dismantling and Assembly, Hoses and Pipes.

! DANGER

Hydraulic Pressure

! WARNING

Hydraulic fluid at system pressure can injure you. Before

Fine jets of hydraulic fluid at high pressure can penetrate

disconnecting or connecting hydraulic hoses, stop the

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

engine and operate the controls to release pressure

fluid leaks. Do not put your face close to suspected

trapped in the hoses. Make sure the engine cannot be

leaks. Hold a piece of cardboard close to suspected

started while the hoses are open.

leaks and then inspect the cardboard for signs of

INT-3-1-11/1

hydraulic fluid. If hydraulic fluid penetrates your skin, get

medical help immediately.

Removal

INT-3-1-10/1

Sideshift the carriage to one side as shown (sideshift

machines only). Lower the backhoe and loader end to

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

the ground and stop the engine.

pressure settings.

Operate the valve block levers back and forth to vent

Note: All hydraulic adapters that are installed together with a

residual pressure.

bonded sealing washer must also have JCB Threadseal

applied to the threads of the adapter.

Remove the hose guide A (this makes access to the

valve block easier).

Remove clevis pins B 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.

Insert two M10 bolts through the eye end spools (three

spools each end) as shown. Make sure the bolt has a

retaining nut on each end. When the bolts are in place

thread suitable slings around the bolts as shown.

! CAUTION

This component is heavy. Do not attempt to remove it

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

sling is attached to a suitable lifting appliance.

HYD 2-3/1

Remove nuts C and lower the valve block to the

ground.

9803/3280

Issue 1

Section E

Hydraulics

Section E

60 - 7

Excavator Valve

60 - 7

Removal and Replacement

Precision Control (Servo)

Disconnect the stabiliser spool control cables 3 as follows:

! DANGER

Undo the lock nut 4.

Hydraulic fluid at system pressure can injure you. Before

disconnecting or connecting hydraulic hoses, stop the

Undo the housing retaining screws 5 and slide the

engine and operate the controls to release pressure

housing down the cable.

trapped in the hoses. Make sure the engine cannot be

started while the hoses are open.

Push out the cable connecting pin 6 and disconnect

INT-3-1-11/1

the cable at the spool. Tie the cables out of harms way.

Removal

Remove the excavator valve as follows:

It is recommended that the valve is removed complete with

For access remove bolts 7 and tie hose guard 8 out of

its mounting plate. The assembly is lowered down and then

the way.

out from under the rear on the machine. Before commencing

make sure that there is sufficient clearance between the

Uncouple electrical connection to the rear horn 9.

machine and the ground. If necessary raise the rear of the

machine using the stabilisers. Chock the machine securely,

Uncouple electrical connection 10 to the hydraclamp

remembering to leave access for removal of the valve

solenoid.

assembly.

Record the phasing of the pilot hoses 11 connected at

The illustration is viewed from the bottom.

the top and bottom of the excavator valve. The hoses

should be labelled, if not label each hose before

Before proceding, vent the hydraulic pressure as follows:

disconnecting, this will ensure correct position when

refitting. Disconnect all hydraulic pilot hoses from the

Stop the engine. With the operator seat set in the rear

valve block and plug all open ends and ports to

facing position (for backhoe operation), switch the

prevent ingress of dirt.

starter to ON without starting the engine. Operate the

joystick controls several times to vent the hydraulic

Record the phasing of the service hoses connected at

pressure from the servo system and backhoe rams.

the front of the excavator valve. Label each hose

before disconnecting, this will ensure correct position

Operate the stabiliser controls several times to vent

when refitting. Disconnect all the hoses from the valve

pressure from the stabiliser rams.

block and plug all open ends and ports to prevent

ingress of dirt.

Turn the starter switch to the OFF position and remove

the key.

Disconnect the inlet 13 and tank return 14 hoses from

the valve block, plug all open ends and ports to

prevent ingress of dirt.

! WARNING

Make the machine safe before working underneath it.

Loosen the three mounting plate bolts 15 - DO NOT

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

completely remove the retaining bolts.

the parking brake, put the transmission in neutral and

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

! CAUTION

Disconnect the battery, to prevent the engine being

This component is heavy. Do not attempt to remove it

started while you are beneath the machine.

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

GEN-1-2

sling is attached to a suitable lifting appliance.

HYD 2-3/1

To avoid damage to the pilot supply valve (shown at A),

Open the rear window. Remove the access plate in the

remove it as follows:

cab floor above the excavator valve. Attach a suitable

sling to the mounting bracket slinging point, make sure

Carfully tag all the hoses connected at the valve. Record

that the weight of the valve is supported by the sling

the phasing. Disconnect the hoses.

(shown at B).

Uncouple the solenoid electrical connector 1.

Remove bolts 15 and lower the valve block to the

ground.

Undo the two fixing bolts 2 and remove the valve.

If the hose adaptors are going to be removed from the

valve block, label before removing to ensure

replacement in the correct ports. Record the positions

of any restrictors.

9803/3280

Issue 2*

Section E

Hydraulics

Section E

60 - 9

Excavator Valve

60 - 9

Removal and Replacement (Cont’d)

Precision Control (Servo)

Replacement

Replacement is a reversal of the removal sequence.

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

and phased in same position as removal.

! WARNING

Fine jets of hydraulic fluid at high pressure can

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

hydraulic fluid leaks. Do not put your face close to

suspected 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 medical help immediately.

INT-3-1-10/1

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

pressure settings.

Torque Settings

Item

kgf m

lbf ft

8 - 11

0.8 - 1.1

6 - 8

9803/3280

Issue 2*

Section E

Hydraulics

Section E

61 - 2

Excavator Valve

61 - 2

Dismantling and Assembly

Manual Control

Assembly

The numerical sequence shown on the illustration is intended

Fit the boot 10 to the seal plate 11.

as a guide to dismantling.

Fit a new lipseal 12A into the valve block, ensure

For assembly the sequence should be reversed.

square. Fit wiper 12 on top of lipseal.

Check Valves

Fit the seal plate and boot assembly to valve block but

do not torque tighten capscrews 9 at this stage. Ensure

wiper locates into seal plate.

Each of the identical load hold check valves 4R to 4W can

be removed as shown at 4W. Make-up check valve 4X is a

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

smaller size but otherwise identical.

insert spool through the valve block, do not use

excessive force when fitting, a turning motion should

Ensure good condition of seating faces on poppets 4 and 8

ease the spool through the valve block.

and on the mating faces in the valve block.

Check that the tang end of the spool passes through

Spools

the boot without dislodging or damaging the boot.

Ensure that the tang aligns with the control rod and

Spools 4A, 4B, 4E and 4F are identical but must not be

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

interchanged as they are matched to their bores. Stabiliser

land.

spools 4C and 4D are identical to each other but different

from the excavator spools.

Torque tighten cap screws 9.

All spools have the same centring and sealing components

When fitting bolt 15, clean the threads thoroughly using

items 9 to 21.

JCB Cleaner/Degreaser, leave it for 10 minutes then

apply a small quantity of JCB Threadlocker and Sealer

To completely dismantle a spool, follow the sequence 9 to

to the threads of the spool.

21. To prevent spool rotation when turning screw 15, hold a

rod through the eye end of the spool.

Make sure that all the parts move freely, check that

item 16 does not interfere with item 18.

If only renewing the seals, dismantle as far as cap 14 then

remove items 15 to 22 as an assembly.

Renew 'O' ring 21 and seal 20. Make sure the 'O' ring

and wiper seal are not trapped or damaged.

Lubricate new seals with JCB Hydraulic Fluid and take care

to prevent them from being damaged by the sharp edges of

Fit seal 20 and seal plate 19 to the valve block section.

the spool.

Torque tighten capscrew 13 on completion.

Apply JCB Threadlocker and Sealer to threads of screw 15.

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

the spool.

Relief Valves

Run the engine and inspect the valve for external leaks.

A.R.V's 4H to 4P appear identical but have various pressure

settings, refer to Technical Data. Ensure that they are

Torque Settings

correctly adjusted and fitted in their specified positions.

Item

kgf m lbf ft

Relief valve dismantling and assembly procedures are

122

12.4

detailed separately.

8.3

9.5

0.96

Note: All hydraulic adapters that are installed together with a

0.7

bonded sealing washer must also have JCB Threadseal

1.1

applied to the threads of the adapter.

9803/3280

Issue 1

Section E

Hydraulics

Section E

61 - 4

Excavator Valve

61 - 4

Dismantling and Assembly

Auxiliary Relief Valves

A.R.V. Position Key

Eight A.R.V's are fitted at positions 4H to 4Q. These are

identical in design but have various pressure settings, refer

Control Layout

to Technical Data.

JCB

ISO

Case

Ford

Note: Valve 4Q is only fitted to machines equipped with a

Slew Right

Powerbreaker.

Slew Left

The numerical sequence shown on the illustration is intended

Boom Rod

as a guide to dismantling.

Boom Head

Dipper Rod

For assembly the sequence should be reversed.

Dipper Head

Dismantling

Bucket Rod

Bucket Head

Dismantle sub-assembly 14 from item 1 using a special tool

(see Service Tools). The special spanner locates in cross

Note: The bucket rod side A.R.V. is only fitted to machines

holes B.

equipped with a Powerbreaker.

Dismantle sub-assembly 14 into its component parts.

Make sure that small drilling A is not blocked.

Discard old and worn O-rings and back-up rings.

Assembly

Renew all O-rings and back-up rings.

Lubricate O-rings and back-up rings with JCB Hydraulic

Fluid.

Fit back-up ring 13 on the upper side of 'O' ring 12 as shown

in the inset.

Fit flat face of sleeve 9 against shoulder of poppet 10.

Torque tighten item 14 using the special tool (see Service

Tools), until its shoulder seats firmly against item 1.

Pressure test the relief valves, refer to Service Procedures,

Excavator Valve - Pressure Testing.

Torque Settings

Item

kgf m

lbf ft

6.6

2.5

9803/3280

Issue 2*

Section E

Hydraulics

Section E

61 - 5

Excavator Valve

61 - 5

Dismantling and Assembly

Hydraclamp Valve - (Sideshift Machines)

(Not Precision Control Machines)

Torque Settings

The numerical sequence shown on the illustration is intended

as a guide to dismantling. For assembly the sequence

should be reversed.

Item

kgf m

lbf ft

13.5

1.4

The following points MUST be avoided when dismantling

24.5

2.5

and assembling the valve:

13.5

1.4

• CONTAMINATION

5.5

0.5

• DAMAGE TO POPPET AND SEAT

24.5

2.5

• DAMAGE TO SEAL GROOVES

All or any of the above points may result in possible

problems with the valve.

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

rounded tool that WILL NOT cause any damage to the seal

grooves. Discard ALL 'O' rings DO NOT use worn or

damaged items.

Note that the hydraclamp comprises two separate valve

assemblies; 1) the check valve assembly (items 1 to 8); 2) the

solenoid assembly (items 11 to 14).

Dismantling

Loosen nut 1 (turn anti-clockwise) and then remove the

check valve assembly from the valve block. If required, the

check valve assembly can be dismantled into its component

parts (items 1 to 8).

Inspect the valve components for scratches, nicks or any

other type of damage, particularly on the poppet and seat

faces. Replace with new if required.

Assembly

Renew all 'O' rings. The parts microfiche will identify the

correct seal kit part numbers for items 2, 2A, 4, 6, 10 and 14.

Fit seal 2A with the recess towards ‘O’ ring 2, as shown at A.

Lubricate parts with JCB Hydraulic Fluid before assembling.

Make sure that all the parts move freely.

Ensure that the small drilling through the centre of item 3, is

clear.

Do not over-tighten the solenoid assembly, it may affect the

operation of the solenoid, use the spanner flats and torque

tighten to figure indicated in the table below (items 11 and

13).

Check the operation of the electric hydraclamp, refer to

Circuit Descriptions, Excavator Valve - Manual Control -

S217500

Hydraclamp Valve Operation.

9803/3280

Issue 2*

Section E

Hydraulics

Section E

62 - 2

Excavator Valve

62 - 2

Dismantling and Assembly

Precision Control (Servo)

(Machines up to serial no. 931159)

Introduction

Relief Valves

The numerical sequence shown on the illustration is intended

A.R.V's RA to RF appear identical but have various pressure

as a guide to dismantling. Be sure to note the location of all

settings, refer to Technical Data. Ensure that they are

components when dismantling. Although some components

correctly adjusted and fitted in their specified positions.

may appear to be identical they are not interchangeable.

Make sure that components are assembled in their original

Relief valve dismantling and assembly procedures are

positions.

detailed separately.

For assembly the sequence should be reversed.

Bypass Compensator Valve

Load Sense (Isolator/Compensator) Valves

The bypass compensator valve is shown at H. Note that the

assembly L is a blanking spool and would not normally need

Each of the load sense valves JA to JG can be removed as

to be removed.

shown at JA. Note that all valves are identical in appearance

except valve JE. This valve is of the same configuration but

Load Sense Drain Regulator and Relief Valve

is dimensionally different. Note that components are not

interchangeable, see the introduction above.

The dismantling and assembly procedure for the drain

regulator and relief valve assembly K is detailed separately,

Spools

see Drain Regulator and Relief Valve.

Note that the not all the spools are shown with their

components. This is because some spool assemblies are of

the same configuration:

When assembling apply JCB Threadlocker to the

For spools F and E see spool B.

following components:

For spools D and C see spool G. Note that the spools are

inverted relative to spool G.

A13

Stabiliser spools 1D and 4E are identical to each other but

different from the excavator spools. Spools must not be

interchanged as they are matched to their bores

Torque Settings

To dismantle spools C, D and G hold a rod through the eye

end of the spool to prevent it rotating when undoing the

Item

kgf m

lbf ft

screw at the opposite end. To dismantle spools B, E and F

8 - 11

0.8 - 1.1

6 - 8

use allen keys in both screws, holding one whilst undoing the

8 - 11

0.8 - 1.1

6 - 8

other. After removing one screw, hold the spool using

A11

8 - 11

0.8 - 1.1

6 - 8

service tool 992/10100 and then undo the remaining screw.

A13

8 - 11

0.8 - 1.1

6 - 8

8 - 11

0.8 - 1.1

6 - 8

It is strongly recommended that that spool A is not

17 - 21

1.7 - 2.1

12.5 - 15.5

dismantled. The spool has additional valve components in

8 - 11

0.8 - 1.1

6 - 8

each end and can easily be damaged when dismantling. If

B10

17 - 21

1.7 - 2.1

12.5 - 15.5

the spool is damaged then the valve must be renewed. Only

8 - 11

0.8 - 1.1

6 - 8

attempt to dismantle the spool in exceptional circumstances.

8 - 11

0.8 - 1.1

6 - 8

8 - 11

0.8 - 1.1

6 - 8

Lubricate new seals with JCB Hydraulic Fluid and take care

58 - 72

6 - 7.3

43 - 53

to prevent them from being damaged by the sharp edges of

58 - 72

6 - 7.3

43 - 53

the spool.

58 - 72

6 - 7.3

43 - 53

58 - 72

6 - 7.3

43 - 53

Note that the breather groove N in the seal retaining plates

RA - RF

58 - 72

6 - 7.3

43 - 53

G3 must be orientated facing the rear mounting face of the

valve block

9803/3280

Issue 2*

Section E

Hydraulics

Section E

62 - 4

Excavator Valve

62 - 4

Dismantling and Assembly

Precision Control (Servo)

(Machines up to serial no. 931159)

Load Sense Drain Regulator and Relief Valve

The numerical sequence shown on the illustration is intended

as a guide to dismantling.

Note that components 6 - 13 can be dismantled and

assembled without disturbing components 1 - 5. If

components 1 - 5 are dismantled, the valve must be reset to

the correct operating pressure after assembly.

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 7 and 8.

Be sure to fit filter screen 11 the correct way round.

Adjust pressure setting as required.

Torque Settings

Item

kgf m

lbf ft

8 - 11

0.8 - 1.1

6 - 8

9803/3280

Issue 2*

Section E

Hydraulics

Section E

62 - 5

Excavator Valve

62 - 5

Dismantling and Assembly

Precision Control (Servo)

Check the operation of the electric hydraclamp, refer to

(Machines up to serial no. 931159)

Circuit Descriptions, Excavator Valve - Precision Control

- Hydraclamp Valve Operation.

Hydraclamp Valve

The numerical sequence shown on the illustration is intended

Torque Settings

as a guide to dismantling. For assembly the sequence

should be reversed.

Item

kgf m

lbf ft

8 - 11

0.8 - 1.1

6 - 8

The following points MUST be avoided when dismantling

4.7 - 6.1

0.5 - 0.6

3.5 - 4.5

and assembling the valve:

41 - 48

4.1 - 5

30 - 36

• CONTAMINATION

• DAMAGE TO BALL SEAT AND PISTON

• DAMAGE TO SEAL GROOVES

All or any of the above points may result in possible

problems with the valve.

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

rounded tool that WILL NOT cause any damage to the seal

grooves. Discard ALL 'O' rings DO NOT use worn or

damaged items.

Note that the hydraclamp comprises two separate valve

assemblies; the clamp valve assembly shown at A and the

solenoid assembly shown at B.

Dismantling

Unsecrew the clamp valve assembly A from the excavator

valve block. Withdraw the piston 3 from the excvator valve

block, if necessary use thin nose pliers.

Hold the body 1 and undo the spring retaining plug 4.

Withdraw the spring 5 and ball 6.

Undo the nut 7 and remove solenoid coil 8. Undo the valve

stem 9.

Make sure that all components and associated cross drillings

are clean and free from debris.

Inspect the valve components for scratches, nicks or any

other type of damage, particularly on the ball and seat faces.

Carefully inspect the outside diameter of the piston 3 and its

bore in the excavator valve block for damage or excessive

wear. Renew components as required.

Assembly

Renew all 'O' rings.

Lubricate parts with JCB Hydraulic Fluid before assembling.

Make sure that all the parts move freely.

Ensure that the small drilling C in the piston 3 is clear.

Do not over-tighten the solenoid assembly, it may affect the

operation of the solenoid, use the spanner flats and torque

A402950

tighten to figure indicated in the table.

9803/3280

Issue 1

Section E

Hydraulics

Section E

62 - 21

Excavator Valve

62 - 21

Dismantling and Assembly

Precision Control (Servo)

(Machines from January 2003)

Dismantling

Service Spools

The excavator valve block is a ‘sandwich type’, which is

Each of the service spools 6 can be removed as shown.

made up of a number of separate sections. The illustration

shown on the opposite page is intended as a guide to

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

dismantling. Be sure to note the location of all components

when removing it from the block. Note that all spools are

when dismantling. Although some components may appear

similar in appearance but must not be interchanged as they

are matched to their bores. All spools have the same

to be identical they are not interchangeable. Make sure that

centring and sealing components.

components are assembled in their original positions.

Remove the excavator valve block from the machine.

Flow Regulator Valve

The dismantling and assembly procedures for the flow

regulator valve 7 are detailed separately, refer to Flow

Remove the three tie rod nuts 1.

Regulator Valve.

Carefully separate and remove the outlet section 2

followed by the remaining service sections 3. If the inlet

Load Sense Relief Valve

section 4 is to be replaced, remove and retain the tie

The dismantling and assembly procedures for the load

sense relief valve 8 are detailed separately, refer to Load

rods 5.

Sense Relief Valve.

Assembly

Flushing Valve

The flushing valve 9 can be removed as shown.

Assembly is the reverse of the dismantling sequence.

Auxiliary Relief Valves

Clean the valve components in an appropriate solvent.

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

Ensure that the mating faces of the valve sections are

settings, refer to Technical Data. Ensure that they are

thoroughly clean before assembly.

correctly adjusted and fitted in their specified positions.

The dismantling and assembly procedures for the ARV’s are

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

detailed separately, refer to Auxiliary Relief Valves (ARV’s).

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

damaged.

Anti-cavitation Valve

The dismantling and assembly procedures for the

Lubricate parts with JCB Hydraulic Fluid before

anticavitation valve 11 are detailed separately, refer to Anti-

assembling. Make sure that all the parts move freely.

cavitation Valve.

Torque Settings

Pressure Compensator Valves

Each of the pressure compensator valves 12 can be

Item

kgf m

lbf ft

removed as shown. Note that all valves are identical in

3.6

25.8

appearance. Note that components are not interchangeable.

7.4

14.8

Load Hold Check Valves

4.6

33.2

Each of the load hold check valves 13 can be removed as

100

10.2

73.8

shown. Note that all valves are identical in appearance.

7.1

51.6

Ensure good condition of seating faces on poppets and on

7.1

51.6

the mating faces in the valve block.

11A

7.1

51.6

6.1

44.3

Hydra-clamp Solenoid Valve

22.1

The hydra-clamp solenoid valve 14 can be removed as

14.8

shown.

14A

4.6

33.2

9803/3280

Issue 1

Section E

Hydraulics

Section E

62 - 22

Excavator Valve

62 - 22

Dismantling and Assembly

Assembly

Assembly is the reverse of the dismantling sequence.

Precision Control (Servo)

(Machines from January 2003)

Clean the valve components in an appropriate solvent.

Flow Regulator Valve

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

Lubricate parts with JCB Hydraulic Fluid before

Removal

assembling. Make sure that all the parts move freely.

It is possible to remove a valve without removing the

Be sure to fit filter gauze 5 the correct way round.

excavator valve block from the machine.

Note: If removing components from a valve block that is

fitted on a machine the pilot circuit accumulator pressure

must be vented first. With the operator seat locked in the

rear facing position and with the arm rests raised forward (for

backhoe operation), switch the starter to ON without starting

the engine. Operate the joystick controls several times to

vent the hydraulic pressure from the servo system and

backhoe rams. Turn the starter switch to the OFF position

and remove the key.

Gain access to the excavator valve and disconnect and

blank any hoses or pipes which may interfere with the

removal of the flow regulator valve.

Unscrew the flow regulator valve from the excavator

valve block. Cover the ports to prevent the ingress of

dirt and remove to a clean working area.

Dismantling

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.

A403850

Unscrew and remove top plug 1.

Carefully remove shims 2, spring 3 and piston 4.

Note: 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, pitting,

corrosion or any other type of damage.

Clean the filter gauze 5 fitted in the end of the valve

body.

Note: If any part other than ‘O’ rings are damaged the entire

valve must be renewed.

9803/3280

Issue 1

Section E

Hydraulics

Section E

62 - 23

Excavator Valve

62 - 23

Dismantling and Assembly

Assembly

Assembly is the reverse of the dismantling sequence.

Precision Control (Servo)

(Machines from January 2003)

Clean the valve components in an appropriate solvent.

Load Sense Relief Valve

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

Lubricate parts with JCB Hydraulic Fluid before

Removal

assembling. Make sure that all the parts move freely.

It is possible to remove a valve without removing the

Adjust the pressure setting as required. Refer to

excavator valve block from the machine.

Service Procedures, Pressure Testing, Load Sense

Relief Valve.

Note: If removing components from a valve block that is

fitted on a machine the pilot circuit accumulator pressure

must be vented first. With the operator seat locked in the

rear facing position and with the arm rests raised forward (for

backhoe operation), switch the starter to ON without starting

the engine. Operate the joystick controls several times to

vent the hydraulic pressure from the servo system and

backhoe rams. Turn the starter switch to the OFF position

and remove the key.

Gain access to the excavator valve and disconnect and

blank any hoses or pipes which may interfere with the

removal of the load sense relief valve.

Unscrew the load sense relief valve from the excavator

valve block. Cover the ports to prevent the ingress of

dirt and remove to a clean working area.

Dismantling

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.

Loosen locknut 1, unscrew and remove adjuster nut 2

and adjuster screw 3.

Carefully remove spring 4 and poppet 5 from valve

body.

Note: 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, pitting,

corrosion or any other type of damage.

A403860

Note: If any part other than ‘O’ rings are damaged the entire

valve must be renewed.

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Issue 1

Section E

Hydraulics

Section E

62 - 24

Excavator Valve

62 - 24

Dismantling and Assembly

Assembly

Assembly is the reverse of the dismantling sequence.

Precision Control (Servo)

(Machines from January 2003)

Clean the valve components in an appropriate solvent.

Auxiliary Relief Valves (ARV’s)

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

Lubricate parts with JCB Hydraulic Fluid before

Removal

assembling. Make sure that all the parts move freely.

It is possible to remove a valve without removing the

Adjust the pressure setting as required. Refer to

excavator valve block from the machine.

Service Procedures, Auxiliary Relief Valve - Setting.

Note: If removing components from a valve block that is

fitted on a machine the pilot circuit accumulator pressure

must be vented first. With the operator seat locked in the

rear facing position and with the arm rests raised forward (for

backhoe operation), switch the starter to ON without starting

the engine. Operate the joystick controls several times to

vent the hydraulic pressure from the servo system and

backhoe rams. Turn the starter switch to the OFF position

and remove the key.

Gain access to the excavator valve and disconnect and

blank any hoses or pipes which may interfere with the

removal of the auxiliary relief valve(s).

Unscrew the auxiliary relief valve(s) from the excavator

valve block. Cover the ports to prevent the ingress of

dirt and remove to a clean working area.

Dismantling

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.

Prise off plastic locking cap.

Loosen locknut 1 and remove adjuster screw 2.

Carefully remove spring 3 and poppet 4.

Unscrew upper valve body 5 and remove springs 6 and

piston 7.

Note: 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, pitting,

A403870

corrosion or any other type of damage.

Note: If any part other than ‘O’ rings are damaged the entire

valve must be renewed.

9803/3280

Issue 1

Section E

Hydraulics

Section E

62 - 25

Excavator Valve

62 - 25

Dismantling and Assembly

Assembly

Assembly is the reverse of the dismantling sequence.

Precision Control (Servo)

(Machines from January 2003)

Clean the valve components in an appropriate solvent.

Anti-cavitation Valve

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

Lubricate parts with JCB Hydraulic Fluid before

Removal

assembling. Make sure that all the parts move freely.

It is possible to remove a valve without removing the

excavator valve block from the machine.

Note: If removing components from a valve block that is

fitted on a machine the pilot circuit accumulator pressure

must be vented first. With the operator seat locked in the

rear facing position and with the arm rests raised forward (for

backhoe operation), switch the starter to ON without starting

the engine. Operate the joystick controls several times to

vent the hydraulic pressure from the servo system and

backhoe rams. Turn the starter switch to the OFF position

and remove the key.

Gain access to the excavator valve and disconnect and

blank any hoses or pipes which may interfere with the

removal of the anti-cavitation valve.

Unscrew the anti-cavitation valve from the excavator

valve block. Cover the ports to prevent the ingress of

dirt and remove to a clean working area.

Dismantling

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.

Unscrew and carefully remove the top nut 1 complete

with piston 2 from the valve body.

Remove the piston 2 and spring 3 from the top nut

spindle.

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

A403880

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, pitting,

corrosion or any other type of damage.

Note: If any part other than ‘O’ rings are damaged the entire

valve must be renewed.

9803/3280

Issue 1

Section E

Hydraulics

Section E

70 - 1

Hose Burst Protection Valves

70 - 1

Removal and Replacement

! WARNING

Disconnect all hydraulic hoses from the HBPV and plug

all orifices to prevent ingress of dirt. Label each hose

Make the machine safe before working underneath it.

before disconnecting, this will ensure correct position

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

when refitting.

the parking brake, put the transmission in neutral and

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

Undo the retaining clips A and remove the HBPV.

Disconnect the battery, to prevent the engine being

Replacement

started while you are beneath the machine.

GEN-1-2

Replacement is a reversal of the removal sequence.

! DANGER

! WARNING

Hydraulic fluid at system pressure can injure you. Before

disconnecting or connecting hydraulic hoses, stop the

Fine jets of hydraulic fluid at high pressure can

engine and operate the controls to release pressure

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

trapped in the hoses. Make sure the engine cannot be

hydraulic fluid leaks. Do not put your face close to

started while the hoses are open.

suspected leaks. Hold a piece of cardboard close to

INT-3-1-11/1

suspected leaks and then inspect the cardboard for

signs of hydraulic fluid. If hydraulic fluid penetrates your

Removal

skin, get medical help immediately.

INT-3-1-10/1

Park the machine on firm level ground, engage the

parking brake and set the transmission to neutral.

After refitting the valve to the machine, ensure that the valve

Lower the backhoe and loader end to the ground and

operates correctly, refer to Service Procedures, Hose

stop the engine.

Burst Protection Valves - Checking.

Note: Refer to Service Procedures, Hose Burst Protection

Valves, Lowering a Load - In a Failure Condition for

lowering a load with engine failure or a burst hose.

Turn the manual over-ride screw fully clockwise.

Operate the main service control levers back and forth

to vent residual pressure. For instance, if the HBPV is

fitted on the boom or dipper then operate the backhoe

control levers. If the HBPV is fitted on the loader arms

then operate the loader control levers.

324250

323590

A260734

9803/3280

Issue 1

Section E

Hydraulics

Section E

70 - 2

Hose Burst Protection Valves

70 - 2

Dismantling and Assembly

- Loader Lift Ram

This procedure applies to Hose Burst Protection Valves

Assembly

fitted to the loader arm rams ONLY.

DO NOT apply JCB Threadlocker and Sealer or any other

The numerical sequence shown on the illustration is

type of locking fluid to the threads of item 17. The threads

intended as a guide to dismantling.

form an integral part of the valve operating sequences -

applying locking fluid to the threads will seriously effect the

For assembly the sequence should be reversed.

operation of the valve.

Dismantling

Ensure that the small drilled holes C and D in items 2 and 17

respectively are not blocked.

If possible, avoid disturbing pressure settings, remove

cartridges by unscrewing hexagons 1 and 13 and do not

Renew all seals. If fitting new Teflon rings A & B, use a

remove capnuts 3 and 16.

conical guide, such as item E, to expand the rings gradually.

Complete the ring fitting procedure as quickly as possible,

Spool 2 and check valve 11 each have a Teflon ring fitted

otherwise the ring will stretch. See below.

(items A and B respectively). These Teflon rings should only

be removed and replaced with new ones if they are

Note: There is an O-ring F fitted underneath each Teflon

damaged.

ring, if the Teflon rings are to be renewed, make sure that

new O-rings are fitted first.

Do not try to dismantle items 20, 21 and 22 (these items are

shown for pictorial reference only). To clean, use a non-

After assembly, make sure that the valve parts move freely,

metallic probe to move the ball 21 against spring 22 whilst

if they don't, check that all the seals are correctly fitted.

assembly 17 is submersed in cleaning fluid.

After refitting the valve to the machine, ensure that pressure

Check condition of all visible seating faces. If any are

settings are correct, see Technical Data page, and check

damaged, renew complete cartridge or valve assembly.

that the valve operates correctly.

Check valve bores and spools for nicks, scratches or

If the pressure settings were disturbed, then the valve must

scoring, if necessary, renew complete cartridge or valve

be re-set, refer to Service Procedures, Hose Burst

assembly.

Protection Valves, Pressure Testing - Loader Lift Ram.

325780

A183490

9803/3280

Issue 1

JCB 3CX, 4CX, 214e, 214, 215, 217 & VARIANTS Backhoe Loader. Service Manual - page 19