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

Steer Unit Operation

- 4 Wheel Steer Machines

4 Wheel Steer Mode

- Shock Valve

In normal operation oil flow from the pump enters

the steering unit via the right hand port, opening a

spring-loaded non-return valve 43C. The flow is

directed by the steering unit to achieve the desired

turn (right hand shown).

In the event of a pressure shock wave being

generated in the system by an outside force, shock

valve 43A vents this pressure to exhaust preventing

damage to the steering unit.

Non-return valve J2 is held on its seat by the

generated pressure and non-return valve 43C

closes to prevent the shock wave being fed back to

the pump. Some of the excess flows via non-return

valve J1 to the opposite side of the power track rod

ram to prevent cavitation occuring.

Component Key:

A Inner Spool

B Outer Spool

D Stator

X Steer Mode Control Valve

Non-Return Valve

43A Shock Valve

43C Non-Return Valve

Steer Unit Operation

- 4 Wheel Steer Machines

2 Wheel Steer Mode

- Right Turn

The illustration shows the flow through the steering

unit in a right hand turn condition. The operation is

identical to that described for the 4 wheel steer

mode, except the steer mode control valve X

iscolates the oil flow to the rear power track rod

ram 41, consiquently the rotor lobes pump oil out

to the front power track rod only. The rear wheels

are held in the straight ahead position by the

locked-up oil in the rear power track rod ram.

In 2 wheel steer mode the spools of the steer mode

control valve X are configured as shown.

Component Key:

A Inner Spool

B Outer Spool

D Stator

LS Load Sensing Port

X Steer Mode Control Valve

Front Power Track Rod Ram

Rear Power Track Rod Ram

43B Relief Valve

43C Non-Return Valve

A395740

Steer Unit Operation

- 4 Wheel Steer Machines

Crab Steer Mode

- Right Turn

The illustration shows the flow through the steering

unit in a right hand turn condition. The operation is

identical to that described for the 4 wheel steer

mode, except the steer mode control valve X

directs the pressurised oil from the front power

track rod ram 40 to the other side of the rear power

track rod ram 41, hence turning the rear wheels in

the same direction as the front wheels, causing the

machine to crab to the right.

In crab steer mode the spools of the steer mode

control valve X are configured as shown.

Component Key:

A Inner Spool

B Outer Spool

D Stator

LS Load Sensing Port

X Steer Mode Control Valve

Front Power Track Rod Ram

Rear Power Track Rod Ram

43B Relief Valve

43C Non-Return Valve

A395750

Priority Valve Operation 2

- Turning

As the steering unit 43 is operated, pressure is

applied to the spring end of the priority valve spool

2B via sensing line LS from the steering unit.

This reduces the pressure differential across the

spool, causing it to move to the right under spring

force. This allows priority valve flow to the steering

unit which directs the flow to the power track rod

rams 40 and 41 untill the required steering lock is

reached. When the steering lock is held the

pressure signal across the side port LS of the

steering unit ceases, restoring the pressure

differential across spool 2B. The spool moves back

to the left, allowing full pump flow to the loader

control valve 3.

Because the pump output is always greater than

the flow required to operate the steering system,

flow to the loader valve is never completely cut off.

Maximum steering system pressure is controlled by

relief valve 43B, located in the steering unit 43.

Component Key:

LS Load Sensing Port

P From pump

T To Loader Valve

Priority Valve

Spring

Spool

Drilling

Loader Valve

Front Power Track Rod Ram

Rear Power Track Rod Ram

Steer Unit

43B Relief Valve

Section H

Steering

Section H

10 - 1

Fault Finding

10 - 1

Fault Finding Contents

Introduction

Page No.

The purpose of this section is to help you trace hydraulic

faults to a faulty unit (valve, actuator, ram etc). Once you

have traced the faulty unit, refer to the appropriate

Introduction

10 - 1

dismantling, inspecting and test instructions given elsewhere

in the steering section.

Steering wheel difficult to turn

10 - 1

To help identify circuits, valves, rams etc mentioned in the

Steering wheel turns on its own

10 - 2

fault finding procedures, refer to the hydraulic schematic

Machine will not turn when the

diagrams (near the beginning of the Hydraulics Section).

steering wheel turned.

10 - 2

Before you begin fault finding, read the Safety

information at the beginning of this manual.

Steering fails to respond to

selected mode (4WS Machines only)

10 - 3

Make simple checks before say, stripping a major

component.

Make sure that the hydraulic fluid is at correct working

temperature (50 °C, 122 °F).

What ever the fault, check the condition of the hydraulic

fluid. Drain and replace if necessary.

Make any relevant electrical checks before moving on

to the hydraulics.

Be sure to remove ALL contamination and if possible

identify its origin. It may be part of a component from

elsewhere in the circuit.

Replace any seals such as 'O' rings before re-

assembling hydraulic components.

Fault

Probable Cause

Action

Steering wheel difficult to turn.

Tyres not inflated to

Inflate tyres to correct

correct pressure

pressure

Insufficient hydraulic fluid.

Check for leaks and top

up the hydraulic tank as

required.

Leaks in the relevant hoses or

Check hoses and

component connections

connections for leaks

Air in the hydraulic system.

Bleed system - bleed the

load sense line.

Low pump flow.

Check pump flow, if

required service or

replace pump.

Steer relief valve set

Check pressure setting

incorrectly

of steer unit relief valve,

adjust as required.

Worn or damaged parts in the steer

Remove and inspect.

control valve.

....... continued

9803/3280

Issue 1

Section H

Steering

Section H

10 - 2

Fault Finding

10 - 2

Fault

Probable Cause

Action

Steering wheel difficult to turn.

Priority valve not operating

Check if the priority valve

(continued)

correctly

is sticking, rectify as

required.

Check the load sense line

from the steer unit to the

priority valve for signs of

leaking

poor

connection.

Steer mode valve not operating

Check if spools sticking,

correctly (4WS Machines only)

rectify as required

Check if solenoids

operating,

replace

solenoids as required

Mechanical failure

Check for damaged axle

components, such as

rams, trackrods, linkages

etc.

Steering wheel turns on its own.

Dirt in the steer control unit

Clean and inspect unit.

(causing sleeves to stick open)

Steer control valve centring springs

Check steer unit.

damaged, broken or missing.

Steer control valve - position of

Refer to Hydraulic Steer

rotor to shaft slot incorrect.

Unit - Dismantling and

Assembly.

Correct as required.

Machine will not turn when the

Insufficient hydraulic fluid.

Check for leaks and top

steering wheel turned.

up the hydraulic tank as

required.

Leaks in the relevant hoses or

Check hoses and

component connections

connections for leaks

Air in the hydraulic system.

Bleed system - bleed the

load sense line.

Low pump flow.

Check pump flow, if

required service or

replace pump.

Steer relief valve set

Check pressure setting

incorrectly

of steer unit relief valve,

adjust as required.

Worn or damaged parts in the steer

Remove and inspect.

control valve.

9803/3280

Issue 1

Section H

Steering

Section H

10 - 3

Fault Finding

10 - 3

Fault

Probable Cause

Action

Machine will not turn when the

Priority valve not operating

Check if the priority valve

steering wheel turned (continued).

correctly

is sticking, rectify as

required.

Check the load sense line

from the steer unit to the

priority valve for signs of

leaking

poor

connection.

Steer mode valve not operating

Check if spools sticking,

correctly (4WS Machines only)

rectify as required

Check if solenoids

operating,

replace

solenoids as required

Mechanical failure

Check for damaged axle

components, such as

rams, trackrods, linkages

etc.

Steer column splined shaft not fully

Check shaft

engaged in steer valve.

engagement.

Power track rod failure

Check power track rod for

signs of damge, leaks etc.

Steering fails to respond to

Selector switch faulty

Check selector switch,

selected mode (4WS Machines only)

replace as required

Proximity switches not operating

Check setting of

correctly

Proximity switches, reset

or replace switches as

required.

Steer mode valve not operating

Check if spools sticking,

correctly

rectify as required

Check if solenoids

operating,

replace

solenoids as required.

Leaks in the relevant hoses or

Check hoses and

component connections

connections for leaks

Electrical failure

Check relevant electrical

connectors, if problem

still persists, do a wiring

continuity check on

relevant circuits.

9803/3280

Issue 1

Section H

Steering

Section H

20 - 1

Service Procedures

20 - 1

Steering System - Bleeding

Whenever any hydraulic steering component is

disconnected or removed the system must be bled as

follows.

With the engine running, the following procedure must be

carried out in the correct order that is laid down. You must

not alter the order of selections and operations.

Select 2 Wheel Steer

(a) Turn steering wheel to left, until front wheels are

fully locked to the left.

(b) Turn steering wheel to right, until front wheels are

fully locked to the right.

Select 4 Wheel Steer

(a) Turn steering wheel to left, until front wheels are

fully locked to the left.

Select 2 Wheel Steer

(a) Turn steering wheel to full right lock.

(b) Turn steering wheel to full left lock.

Select 4 Wheel Steer

(a) Turn steering wheel to left, until the front wheels

are fully locked to the left.

Select 2 Wheel Steer

(a) Turn steering wheel to full right lock.

(b) Turn steering wheel to full left lock.

Select 4 Wheel Steer

(a) Turn steering wheel to left, until front wheels are

fully locked to the left.

Select 2 Wheel Steer

(a) Turn steering wheel to full right lock.

(b) Turn steering wheel to full left lock.

Select 4 Wheel Steer

(a) Turn steering wheel to left, until the front and rear

wheels are fully locked.

9803/3280

Issue 1

Section H

Steering

Section H

20 - 2

Service Procedures

20 - 2

Steering System - Pressure Testing

Park the machine on level ground, engage the parking

brake and set the transmission to neutral. Lower the

attachments to the ground. Stop the engine and

remove the starter key.

Turn the steering wheel to the left and to the right

several times to vent system pressure.

! WARNING

Make the machine safe before working underneath it.

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

the parking brake, put the transmission in neutral and

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

Disconnect the battery, to prevent the engine being

started while you are beneath the machine.

GEN-1-2

Connect a 0-400 bar (0-6000 lbf/in²) pressure gauge to

test adaptor A.

Note: The pressure test point for the steering circuit is fitted

next to the priority valve as shown.

Run the engine at 1500 revs/min and turn the steering

to full lock. Check the gauge reading which should

equal the relief valve pressure, refer to Technical Data.

S212750

Note: The steering wheel must be held on full lock whilst the

gauge reading is being checked.

If necessary, adjust the pressure setting by removing

plug B, on the hydraulic steer unit.

Adjust screw C using an 'allen key' until the correct

pressure is shown on the gauge.

Note: Detail X shows a relief valve which has a 4 mm

hexagon adjusting screw. Detail Y shows a valve which has

a 6 mm hexagon adjusting screw.

Refit plug B.

S263940

A390590

9803/3280

Issue 1

Section H

Steering

Section H

20 - 3

Service Procedures

20 - 3

Proximity Switch - Setting

! WARNING

Raised loader arms can drop suddenly and cause

serious injury. Before working under raised loader arms,

fit the loader arm safety strut.

GEN 3-2

Note: The proximity switch setting procedure is the same for

both the front and rear axles. The illustration shows a typical

rear axle.

Align the wheels in the straight ahead position. Check if

straight ahead by measuring the steering ram position.

Set the steering so that dimension X is equal both

sides.

Remove the proximity switch cover C.

With the starter switch on, loosen the proximity switch

lock nut D and slide the switch in line with the target

disc A.

Loosen the bracket fixing bolts E and adjust the

assembly up or down to bring the switch to the centre

of the target disc. Tighten the fixing bolts E.

Make sure the light emitting diode (L.E.D.) is not

illuminated (if it is then screw the switch out).

Now screw the proximity switch towards the target disc

until the light emitting diode (L.E.D.) on the switch

illuminates. Add a further 1 to 1.5 turns of the locknut.

Tighten the locknut.

A258170

9803/3280

Issue 1

Section H

Steering

Section H

20 - 4

Service Procedures

20 - 4

Steer Mode Valve

- Checking Solenoid Operation

The solenoids operate according to the steer mode that is

selected.

Mode:

Solenoid(s) Energised:

2 Wheel Steer

4 Wheel Steer

X, Z

Crab Steer

X, Y

Operation (energisation) of a solenoid can be easily detected

by placing a steel object (e.g. screwdriver blade) close to the

outer casing. A magnetic attraction of the steel object

towards the solenoid indicates energisation.

If a solenoid is not energising carryout the following checks:

Check the fuse is intact. If not, renew and then check

that all steer mode solenoid combinations function

correctly.

If the fuse is intact remove the electrical connector from

the malfunctioning solenoid(s) and check that the 12V

supply is present across the connector pins. If not,

check the supply circuit.

Check the solenoid coil resistance which should

measure a few ohms (if unsure of the value compare

with a known good solenoid).

Renew the solenoid if the reading indicates a short

circuit (zero ohms) or open circuit (infinate resistance). If

a reading somewhere between the two is obtained,

reverse the two instrument probes and repeat for a

valid check.

A396570

9803/3280

Issue 1

Section H

Steering

Section H

20 - 5

Service Procedures

20 - 5

Priority Valve - Cleaning

The priority valve spool and spring may be removed for

cleaning.

Remove the priority valve from the machine. Refer to

Priority Valve - Removal and Replacement.

Unscrew adaptor 9 and extract the priority valve spring

11.

Remove the blanking plug 7. Press out the priority valve

spool 12 using a nylon pin. Take care not to damage

the bore of the valve.

Clean these components in clean paraffin paying

particular attention to the orifices at each end of the

spool. Dry off and lubricate with clean hydraulic fluid.

Refit the priority valve spool 12 making sure that the

spring seat end of the spool faces towards the LS port.

Refit blanking plug 7 and torque tighten.

Refit the priority valve spring 11 and adaptor 9 and

torque tighten.

Refit the valve onto the machine. Refer to Priority

Valve - Removal and Replacement.

Bleed the load sensing line. Refer to Priority Valve -

Bleeding.

Torque Settings

Item

Ibf ft

9803/3280

Issue 1

Section H

Steering

Section H

20 - 6

Service Procedures

20 - 6

Priority Valve - Standby Pressure Testing

Disconnect hose A and install a 0 - 40 bar (0 - 580

lbf/in²) pressure test gauge into the valve port. Position

the open end of hose A into a clean container in order

to collect any oil drainage.

Disconnect hose B from load sensing port adaptor C

and blank off.

Set the steering to neutral, i.e. do not turn the steering

wheel, and start the engine. Gradually increase the

engine speed to 1000 rev/min while checking the

maximum pressure gauge reading which should be 5.9

to 8.7 bar (86 to 126 lbf/in²)

If the pressure is outside the limits try cleaning the priority

valve, refer to Priority Valve - Cleaning.

If cleaning the valve does not rectify, check the hydraulic

pump flow rate, refer to Section E Main Pump - Flow and

Pressure Testing.

If the hydraulic pump flow and pressure tests are

satisfactory, then the priority valve must be renewed.

9803/3280

Issue 1

Section H

Steering

Section H

30 - 1

Power Track Rod

30 - 1

Removal and Replacement

This procedure is for a typical power steering track rod

removal and replacement.

! WARNING

Make the machine safe before working underneath it.

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

the parking brake, put the transmission in neutral and

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

Disconnect the battery, to prevent the engine being

started while you are beneath the machine.

GEN-1-2

! WARNING

Raised loader arms can drop suddenly and cause

serious injury. Before working under raised loader arms,

fit the loader arm safety strut.

GEN-3-2

A258510

Removal

Disconnect and cap hydraulic hoses to prevent loss of

fluid and ingress of dirt. Label hoses for identification

and correct refitting.

On 4WD machines remove the split pin and nut A.

Remove the track rod ball joint from the wheel hub

assembly.

On 2WD machines, remove lock assembly B and pin C

to remove the track rod pivot from the wheel hub

assemblies.

Remove the four fixing bolts D.

Replacement

Replace the power track rod by reversing the removal

procedure. On 4WD machines make sure that the split

pin is fitted.

A258490

After connecting hoses check hydraulic fluid level, if

necessary top up.

Bleed hydraulic steering system, refer to Service

Procedures, Steering System - Bleeding.

Torque Settings

Item

kgf m lbf ft

620

457

A258500

9803/3280

Issue 1

Section H

Steering

Section H

31 - 2

Power Track Rod

31 - 2

Link Arms - Removal and Replacement

Removal

Replacement

Fix the assembly on a locally made strip/rebuild bench

Replacement is the reverse of removal but note the

as shown.

following:

Using two suitable open ended spanners at L and M

Remember to fit the target disc G (where applicable).

react against each other until one ball joint unscrews.

Use JCB Threadlocker & Sealer on the trackrod link

arms.

Unscrew the ball joint L until an open ended spanner

can be fitted on the rod N. Screw the ball joint against

If the link arms have been renewed, the wheel

the spanner to secure the spanner and to prevent

alignment must be checked as follows:

damage to the rod.

a Set the wheels to the straight ahead position and

measure dimensions X and Y (at the outer edge of

By reacting against the spanner at N and M undo the

the wheel hub). Alignment is correct if the

other ball joint.

difference between X and Y is a maximum of 1

mm.

Note 1: Flats at ‘E’ are:

2 Wheel drive machines - 32 mm A/F x 4 mm wide.

b To adjust the wheel alignment undo the lock nuts

4 Wheel drive machines - 40 mm A/F x 4 mm wide.

(H or K as applicable). Turn the threaded adjusters

J equally to obtain the correct alignment. Tighten

Note 2: The piston rod operates at full length, any damage

the lock nuts (H or K as applicable).

to the surface will cause fluid leaks. DO NOT attempt to grip

the rod diameter with pipe grips etc.

Note 4: AWS machines shown at A. 2 wheel steer machines

shown at B.

Repeat the procedure for the remaining link arm

assembly.

Check the proximity switch setting (where applicable).

Refer to Service Procedures, Proximity Switch -

Where applicable remove the target disc G.

Setting.

Note 3: If the inner or outer ball joints need to be renewed,

then a replacement link arm assembly must be fitted.

Torque Settings

2WS /4WD C 180 Nm (132 lbf ft)

H 45/50 Nm (33/36 lbf ft)

E 240/260 Nm (177/184 lbf ft)

2WS/4WD

C 140/150 Nm (103/110 lbf ft)

K 300 Nm (221 lbf ft)

E 240/260 Nm (177/184 lbf ft)

AWS/4WD C 270/280 Nm (199/206 lbf ft)

H 70/85 Nm (51/62 lbf ft)

E 450 Nm (331 lbf ft)

AWS/4WD C 270/280 Nm (199/206 lbf ft)

K 390/410 Nm (287/302 lbf ft)

E 450 Nm (331 lbf ft)

2WS/2WD

C N/A

K 240/260 Nm (177/184 lbf ft)

E 240/260 Nm (177/184 lbf ft)

9803/3280

Issue 1

Section H

Steering

Section H

32 - 2

Power Track Rod

32 - 2

Rams

Dismantling and Assembly

Assembly

Clean the threads of the end caps and cylinder using a

The numerical sequence shown on the illustration is

wire brush.

intended as a guide to dismantling.

Use JCB Cleaner & Degreaser to ensure that all

For assembly the sequence should be reversed.

threads are free from grease, hydraulic oil and sealant.

Allow 15 minutes for solvent to dry before applying

Dismantling

JCB Threadlocker and Sealer (High Strength).

Fix the ram assembly on a locally manufactured

Ensure that lubricants used during assembly do not

strip/rebuild bench as shown at A.

come into contact with the JCB Threadlocker and

Sealer (High Strength).

Remove both end caps, using a special spanner (refer

to Service Tools). Pull the piston rod assembly from

Refer to Section E Rams - JCB Ram Sealing

the cylinder.

Procedure for the correct method of fitting seals to the

end cap and piston head.

Note 1: DO NOT allow the piston rod to come into contact

with the cylinder bore. The cylinder bore may be damaged

Clamp the cylinder vertically and lower the piston rod

by careless dismantling.

assembly in from the top, as shown at B. Take care not

to allow the piston rod to come into contact with the

Position the piston rod assembly on a bench in place of

cylinder bore. Be sure to engage the piston head new

the ram cylinder. Remove the seal and wear rings from

wear rings and seal carefully into the cylinder. If the

the piston head.

piston head wear rings or seal are damaged during this

stage, they must be renewed.

Note 2: The piston head cannot be removed from the rod. If

there is damage to the rod or piston head, replace the

Apply JCB Activator to threads of the end caps and

cylinder. Allow Activator to dry for 15 minutes before

complete assembly.

bringing into contact with the JCB Threadlocker and

Carefully inspect the bore of the cylinder and the piston

Sealer (High Strength).

rod outer diameter for scoring, nicks and burrs. If such

Note 4: Neither the JCB Threadlocker and Sealer (High

damage is visible the components must be renewed.

Strength) nor Activator must be allowed to contact seals,

bearing rings or ‘O’ rings.

Note 3: If burrs are evident on the ends of the piston rod at

positions C or D remove by careful filing.

Apply JCB Threadlocker and Sealer (High Strength) to

threads of the ends caps, fit new ‘O’ ring 5.

Both end cap assemblies are the same, dismantle as

follows:

Ensure that there are no burrs at the ends of the piston

rod, see Dismantling - Note 3:

Remove the ‘O’ ring 5, end cap seal 6 and wiper seal 7.

Fit an end cap over the piston rod. Apply light hand

The bearing bush 8 can be renewed if necessary.

pressure to the cap to engage the gland seal on the

However, time will be saved if a complete end cap and

piston rod. DO NOT use excessive force. Screw on the

bush assembly is obtained.

first end cap and then fix the assembly on the

strip/rebuild bench as shown at A. Fit the remaining

cap and then torque tighten both caps.

Note

5: If hydraulic oil contacts the uncured JCB

Threadlocker and Sealer (High Strength) a weakening of the

bond will result. Cure times vary according to the ambient

temperature. Allow a minimum of

2 hours between

assembly and filling the ram with oil.

Torque Settings

Item

kgf m lbf ft

678

69.2

500

Note

6: Cold weather operation. When operating in

conditions which are consistently below freezing, it is

recommended that the track rod is operated slowly to its full

extent in both directions before commencing normal

working.

9803/3280

Issue 1

Section H

Steering

Section H

40 - 1

Priority Valve

40 - 1

Removal and Replacement

Dismantling and Assembly

The numerical sequence shown on the illustration is

intended as a guide to dismantling.

! WARNING

Make the machine safe before getting beneath it. Lower

For assembly the sequence should be reversed.

the attachments to the ground; engage the parking

brake; remove the starter key, disconnect the battery.

Note 1: The priority valve is not serviceable beyond the

2-3-2-2

removal of foreign matter (Refer to Service Procedures,

Priority Valve - Cleaning). A faulty unit must be replaced.

The priority valve is mounted on the right hand side chassis

Dismantling

member, adjacent to the loader valve block. It is attached to

the chassis member by one bolt A, and is accessible from

Press out the spool item 12 using a nylon pin. Take care not

underneath the machine.

to damage the bores of the valve.

When replacing always renew sealing ‘O’ rings 2, 4, 6, and

Assembly

10.

Make sure that spring seat of spool 12 faces toward LS

connection.

Clean all parts in clean paraffin.

Lubricate all parts with hydraulic fluid.

Renew aluminium washers 8 and 10.

Note 2: All hydraulic adapters that are installed together with

a bonded sealing washer must also have JCB Threadseal

applied to the threads of the adapter.

Torque Settings

Item

lbf ft

Bleeding

To bleed the LS line, start the engine, loosen the connection

on the valve, turn and hold the steering wheel fully in either

direction. When bubble free oil flows from the joint, tighten

the connection.

9803/3280

Issue 1

Section H

Steering

Section H

45 - 1

Steer Mode Valve

45 - 1

Removal and Replacement

Replacement

! WARNING

Make the machine safe before working underneath it.

! WARNING

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

Fine jets of hydraulic fluid at high pressure can penetrate

the parking brake, put the transmission in neutral and

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

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

fluid leaks. Do not put your face close to suspected

leaks. Hold a piece of cardboard close to suspected

Disconnect the battery, to prevent the engine being

leaks and then inspect the cardboard for signs of

started while you are beneath the machine.

GEN-1-2

hydraulic fluid. If hydraulic fluid penetrates your skin, get

medical help immediately.

INT-3-1-10/1

DANGER

Hydraulic Pressure

Replacement is a reversal of the removal sequence.

Hydraulic fluid at system pressure can injure you. Before

disconnecting or connecting hydraulic hoses, stop the

Make sure that the electrical solenoid connections are

engine and operate the controls to release pressure

refitted in the correct position.

trapped in the hoses. Make sure the engine cannot be

started while the hoses are open.

Make sure that the hoses are correctly installed. The

INT-3-1-11/1

hose connections from the steer mode valves assembly

are as follows:

Removal

P - to hydraulic steer unit (L port)

B - to rear power track rod (left side)

Park the machine on level ground, engage the parking

A - to rear power track rod (right side)

brake and set the transmission to neutral. Lower the

T - to front power track rod (right side)

attachments to the ground. Stop the engine and

remove the starter key.

Note 2: The steer mode valves assembly ports should be

stamped 'P', 'B', 'A' and 'T'. Left and right hand are as

Turn the steering wheel to the left and to the right

viewed from the rear of the machine.

several times to vent system pressure.

Bleed the steering system, refer to Service

Note 1: The steer mode valves assembly is fitted to a

Procedures, Steering System - Bleeding.

bracket which is mounted on the right hand side of the

machine in front of the rear axle.

Disconnect the electrical solenoid connections. Label

each connector before removal to ensure correct

refitting. The wires should be identified A, B, C and D

as shown.

Disconnect all hydraulic hoses from the steer mode

valves assembly. Label the hoses to ensure correct

refitting and cap the ends to prevent ingress of dirt.

Take hold of the steer mode valves assembly, loosen

and remove bolts E. Lift the steer mode valves

assembly and its retaining bracket from the machine.

A396570

9803/3280

Issue 1

Section H

Steering

Section H

45 - 2

Steer Mode Valve

45 - 2

Dismantling and Assembly

The numerical sequence shown on the illustration is

Assembly

intended as a guide to dismantling.

Renew all 'O' rings.

For assembly the sequence should be reversed.

Lubricate parts with JCB Special Hydraulic fluid before

Dismantling

assembling.

Before dismantling scratch an alignment mark X along

Use the alignment marks X (see dismantling) to ensure

the faces of the solenoid valves and the manifold block.

that the solenoids and the manifold block are

assembled correctly.

Note 1: Take care not to lose the detent balls A from items

16 and 18.

Torque Settings

Note 2: The illustration depicts a complete strip down, but

Item

lbf in

to carry out specific servicing/repairs, e.g. renewal of one of

7.1-9.1

63-80

the solenoids 3 and 6, it is only necessary to dismantle the

relevant components.

Note 3: None of the component parts of the CETOPS valve

assembly can be renewed individualy. The extent of

permissible servicing is cleaning and the consequential

renewal of 'O' ring seals. If damage to any component or

distortion of the spool is evident the complete valve

assembly must be renewed.

A396550

9803/3280

Issue 1

Section H

Steering

Section H

50 - 1

Hydraulic Steer Unit

50 - 1

Removal and Replacement

Replacement

Removal

! WARNING

! DANGER

Fine jets of hydraulic fluid at high pressure can penetrate

Hydraulic Pressure

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

Hydraulic fluid at system pressure can injure you. Before

fluid leaks. Do not put your face close to suspected

disconnecting or connecting hydraulic hoses, stop the

leaks. Hold a piece of cardboard close to suspected

engine and operate the controls to release pressure

leaks and then inspect the cardboard for signs of

trapped in the hoses. Make sure the engine cannot be

hydraulic fluid. If hydraulic fluid penetrates your skin, get

started while the hoses are open.

medical help immediately.

INT-3-1-11/1

INT-3-1-10/1

Park the machine on level ground, engage the parking

Replacement is a reversal of the removal sequence.

brake and set the transmission to neutral. Lower the

Make sure that the hoses are correctly installed.

attachments to the ground. Stop the engine and

remove the starter key.

Bleed the steering system. Refer to Service

Procedures, Steering System - Bleeding.

Turn the steering wheel to the left and to the right

several times to vent system pressure.

If a new steering unit has been fitted then the system

relief valve must be tested for correct pressure setting.

Disconnect and cap all hydraulic hoses from the

Refer to Service Procedures, Steering System -

steering unit as shown at A. Label the hoses to ensure

Pressure Testing.

correct refitting.

Note: All hydraulic adapters that are installed together with a

Get an assistant to hold the steering unit, and, working

bonded sealing washer must also have JCB Threadseal

inside the cab, loosen and remove 4 bolts B. Lift the

applied to the threads of the adapter.

steering unit from the machine.

A390610

9803/3280

Issue 1

Section H

Steering

Section H

50 - 3

Hydraulic Steer Unit

50 - 3

Dismantling and Assembly

The numerical sequence shown on the illustration is intended as a guide to dismantling.

Note: 1 During manufacture, a small mark X will have been made on sleeve 12 and spool 15, close to one of the slots for the

centring springs 13. Before removing the centring springs, check that this mark is visible; if not, make a new mark to ensure

correct assembly.

Note: 2 Shock valves (items 29 to 35) are pressure set during manufacture and the adjusting screw 31 secured with Loctite.

Due to the difficulty of resetting the pressure it is recommended that the valves are not disturbed. If dismantling is

unavoidable, however, measure and record the depth of adjusting screw 31 below the top face of the steering unit before

removing the screw.

Note: 3 The unit illustrated in the following sequence represents a typical hydraulic steer valve. The relief valve (items 25 to

28) and shock valves (items 29 to 35) are not therefore shown in the following illustrations.

Assembly

Fit spool 15 into sleeve 12, aligning slots for centring

springs 13 and checking that the small marks X are

aligned. Ensure that three slots in spool partially

uncover three holes in sleeve, as at A.

Fit two flat centring springs 13 with four curved springs

between them, as shown at B.

Fit seal 24 into steer unit body and insert sleeve of

service tool 892/00180. Fit back up ring 20 and seal 21

onto plastic boss, and position on tool spindle, as

shown.

Lower steering unit body and tool sleeve over tool

spindle until plastic bush is flush with end of bore.

Assemble sleeves 12 and 15 with cross pin 14 and

centring springs 13. Fit bearing components 16 to 19

with chamfered face of 17 facing away from bearing 18.

S229680

Remove body from tool leaving plastic bush in position,

and lower body over assembled spool.

Apply downward pressure on body until plastic boss is

forced out of bore, leaving seals correctly located.

S229690

9803/3280

Issue 1

Section H

Steering

Section H

50 - 4

Hydraulic Steer Unit

50 - 4

Assembly (Continued)

Invert unit and place on a suitable hollow support so

that body does not rest on protruding sleeve, thus

preventing displacement of the new seals. Place ball 23

into check valve hole and fit bush 22.

Fit new 'O' ring 10.

Fit distributor plate 9 ensuring that holes align. Locate

shaft 11 onto cross-pin 14, noting position of slot.

When rotor 7 is fitted, slot must align with hollows of

rotor as shown at C.

S229700

Use a suitable piece of rigid flat material, 0.25mm

(0.010 in.) thick, to support the shaft and ensure

positive engagement with the splines of rotor 7.

Locate rotor onto shaft, ensuring alignment as at C. Fit

spacing bush 6 into rotor.

Fit 'O' rings 4 and 8 each side of body 5, then position

body over rotor.

Refit the end plate and fit at least one bolt 2 before

removing support material.

Fit remaining bolts, ensuring that special bolt 1 is

correctly located. Tighten all bolts to 29Nm (22 lbf ft).

S229710

Pressure Relief Valve Cartridge

After renewing the 'O' ring, torque tighten the cartridge to 50 Nm (37 lbf ft). The relief valve is preset, refer to

Technical Data for the valve setting. The relief valve setting should be rechecked after fitting the steering unit to the

machine. Refer to Service Procedures, Steer System - Pressure Testing.

Shock Valves

If the shock valves have been dismantled, clean the threads of adjusting screw 31 and the threads in the bore of the steering

unit body using JCB Cleaner/Degreaser, allow to dry. Assemble seat 35, ball 34, cap 33 and spring 32 then coat threads of

screw 31 with JCB Threadlocker and Sealer. Assemble screw to depth measured during dismantling then fit plug 29 and

washer 30.

9803/3280

Issue 1

Section K

Engine

Section K

2 - 1

Technical Data

2 - 1

Type

1000 Series 4 cylinder Engines

AB - Turbocharged

AA - Naturally Aspirated

AK - Turbocharged

AM - Turbocharged and Intercooled

AR - Naturally Aspirated

Engine Build List Number

AA50608 - AR50656, AR50654, AR50678 - 56kw (75bhp), AK50745 60kw (80bhp)

AA50606 - 56kw (75bhp)

AB50607 - 67.5 kw (90.5bhp), AK50628 - 68.5 kw (92bhp)

AB50609 - 71.5kw (96bhp), AK50640 - 74.6 kw (100bhp) AM50647 85.5 kw (115bhp)

Bore

AA, AB, AK, AM

100mm (3.937 in)

103mm (4.055 in)

Stroke

127mm (5.000 in)

Swept Volume

AB, AA, AK, AM

4 litres (243 in³)

4.23 litres (258 in³)

Compression Ratio

16.0:1

16.5:1

AK, AM

17.25:1

18.5:1

Compression Pressure

28 bar (400 lbf/in²)

[maximum variation between cylinders 3.5 bar (50 lbf/in²)]

Injection Sequence

1,3,4,2

Valve Clearance - Cold

- Inlet

0.20mm (0.008 in)

- Exhaust

0.45mm (0.018 in)

Oil Pressure (hot) at maximum speed

- AA

2.1 bar (30 lbf/in²)

- AB, AK, AM

2.6 bar (40 lbf/in²)

- AR

2.0 bar (30 lbf/in²)

Maximum Air Cleaner Restriction

559mm (22 in H²O)

Injection System Details - Refer to appropriate Engine Service Manual.

Idling Speed

- All builds

880 - 930 rev/min

Maximum Governed Speed

- All builds

2200 rev/min

Maximum No-load Speed (High Idle)

- All builds

2400 - 2440 rev/min

Cooling System

Coolant Pressure

0.48 bar (7 lbf/in²)

Coolant Temperature (Normal)

80-85 °C (176-185 °F)

Temperature Warning Light operates at:

98 °C (208 °F)

Note: For further details of the engines refer to the following Engine Service Manuals:

Publication No. 9806/0100 (AA, AB)

Publication No. 9806/2140 (AK, AM, AR)

9803/3280

Issue 1

Section K

Engine

Section K

20 - 1

Service Procedures

20 - 1

Fuel Lift Pump

- Cleaning the Strainer

To remove and fit pump, see Engine Service Manual.

Remove and clean fuel inlet strainer 2 if blockage is

suspected ie. low engine power, difficult to start, fuel tank

contamination.

Allow the engine to cool. Remove the fuel filler cap to

vent the system and reduce loss of fuel. Disconnect the

fuel inlet pipe to the lift pump.

Unscrew the fuel filter A. Remove strainer 2 and O-ring

Clean the strainer in clean diesel fluid and dry with low

pressure compressed air. Renew the strainer and O-

ring if damaged.

Fit the strainer into the fuel inlet connection. Fit the inlet

connector A and tighten to 20Nm (15 lbf ft). Fit the fuel

inlet pipe carefully to prevent damage to the strainer,

and tighten the union nut.

IMPORTANT: The fuel strainer can be damaged and fuel

flow can be restricted if the fuel pipe is inserted too far

into the inlet connection. This should be checked if a fuel

restriction is suspected.

Make sure the olive on the fuel inlet pipe is in good

condition and forms an effective seal. Renew the olive

or pipe if necessary to prevent air entering the fuel

system.

Fit the tank cap and prime the fuel system. Start the

engine and check for fuel leakage.

366610

9803/3280

Issue 1

Section K

Engine

Section K

30 - 2

Engine

30 - 2

Removal and Replacement

Loosen and remove the exhaust silencer retaining

Removal

bolts, remove the silencer.

Park the machine on firm level ground, engage the

Loosen and remove the retaining clamp for the heater

parking brake and set the transmission to neutral.

Chock the road wheels.

hose. Remove the hose.

Raise the loader arms and fit the loader arm safety

Loosen and remove the retaining clamp for the air filter

strut.

intake hose.

Note: In the event of engine failure, the loader arms will have

Remove the air intake filter. Use tape to close the

to be raised using suitable lifting equipment. Make sure that

opening in the air intake manifold, this will prevent

the loader control lever is in the ‘raise arms’ position before

ingress of dirt.

manually lifting the loader arms.

Loosen and remove the brake master cylinder reservoir

Remove the engine side panels

retaining bolts. Do not remove the pipes attached to

the master cylinder reservoir but put the reservoir out

Remove the engine cover (including the exhaust stack).

of the way. Make sure that the fluid level does not drain

down.

Disconnect the battery. When disconnecting the

battery, take off the earth (black) lead first.

Label and remove all electrical connections, the

number of connectors will vary depending on the

Remove retaining bolts and then lift off the front grille.

ancillary equipment fitted to the engine. Typical

electrical connectors are:

Remove retaining bolts A and B (both sides) and lift off

starter motor

the front nose guard.

ii)

alternator

iii)

coolant pressure switch

Disconnect the hydraulic oil cooler hoses C from the

iv)

coolant temperature sender

hydraulic oil cooler. Plug and cap open ports to prevent

engine oil pressure switch

ingress of dirt.

vi)

engine temperature sender

vii)

engine shut off solenoid

Note: When installing and removing hoses from the cooler, it

viii)

ether cold start (if fitted)

is essential to note that adaptor D must be held with a

ix)

air conditioning compressor (if fitted)

spanner whilst installing or removing the hose. It may be

easier to remove the top hose connection once the cooler

If air conditioning is fitted:

has been removed from the machine.

Note: The air conditioning is a pressurised closed loop

Drain the cooling system.

system, do not disconnect the hoses to the compressor.

Leave the hoses to the compressor intact.

Remove the transmission oil cooler hoses E.

a Remove the belt from the clutch of the air

Remove the radiator top hose and bottom hose.

conditioning compressor.

Remove the coolant bottle pipe.

b Disconnect the electrical connectors at the

compressor.

Make a suitable alignment mark to allow correct

repositioning of the radiator shroud, as shown at F.

c Loosen and remove the air conditioning

compressor retaining bolts.

If an engine fan guard is fitted, remove retaining bolts

and lift off the guard.

d Put the air conditioning compressor out of the way

(do not allow the compressor to ‘hang’ on its

Remove retaining bolts G (both sides) and lift off the

hoses).

radiator sub-assembly including radiator, hydraulic and

transmission coolers, and shroud. Take care not to

Loosen and disconnect the fuel lines J from the fuel

damage the engine fan, note also that the sub-

sedimenter. Plug and cap open orifices to prevent

assembly is heavy, use suitable lifting equipment.

ingress of dirt and loss of fuel.

Note: If required, the shroud, radiator and coolers can be

Loosen and remove the retaining bolts for the fuel

removed as individual items.

sedimenter, remove the sedimenter K.

......cont’d

9803/3280

Issue 1

Section K

Engine

Section K

30 - 3

Engine

30 - 3

Removal and Replacement

Replacement

Removal (continued)

Replacement is a reversal of the removal procedure.

If fitted, loosen and disconnect the ether cold start fuel

line from the engine. Plug and cap open orifices to

When mating the gearbox/torque converter to engine,

prevent ingress of dirt and loss of fluid.

ensure that the drive tangs are correctly located in the

gearbox pump. See Section F Gearbox Replacement

If fitted, loosen and remove the ether cold start canister

for a detailed procedure.

retaining bolts, lift off the canister and retaining bracket

assembly.

Note: It is vitally important that the torque converter is

fitted at the gearbox and engine flywheel correctly.

Disconnect the throttle linkage L from the arm on the

Failure to locate the converter correctly will result in damage

fuel injection pump. Leave at least one of the locking

to the gearbox oil pump on engine start up.

nuts in position, this will ensure that the engine revs are

set correctly when reassembling.

When you are satisfied that the torque converter is

located correctly, use the access hole in the bottom of

Loosen and remove the rear propshaft to gearbox

the gearbox to fit and tighten the flexi-plate to engine

retaining bolts M.

flywheel retaining bolts. Rotate the flywheel to align the

next bolt hole, fit and tighten all retaining bolts.

On 4WD machines, loosen and remove the front

propshaft to gearbox retaining bolts N.

When fitting the radiator sub-assembly, including

radiator, cooler and shroud take care not to damage

Remove the access bung located at the base of the

the engine fan, align the shroud using alignment mark

gearbox. Through the access hole, loosen and remove

made at step 13 in Removal.

the torque converter to engine flywheel retaining bolts

P (turn the flywheel to align bolts with access hole).

Make sure that the front nose guard and the engine

cover are correctly aligned.

If manual gearbox fitted, disconnect the gearshift lever

from the top of the gearbox.

Refill cooling system using correct mixture of

water/anti-freeze.

Use a suitable trolley jack and support the weight of the

gearbox.

Check engine, coolant and brake oil levels.

Note: Attach a ‘cradle’ to the trolley jack that will evenly

When connecting the battery, connect the earth (black)

support the weight of the gearbox. Refer to Service Tools.

lead last.

Use a suitable stand and support the weight of the

Make sure that the engine idle speed is correct, adjust as

engine.

required, refer to Technical Data.

Loosen and remove the gearbox mounting bolts Q.

Torque Figures

Remove the gearbox to engine retaining bolts R, pull

Item Nm

Kgf m

lbf ft

Description

the transmission and converter clear of the engine,

118

Rear propshaft bolts

make sure that the converter stays mounted on the

Front propshaft bolts

gearbox shaft.

4.5

Flexi-plate to flywheel bolts

237

175

Gearbox mounting bolts

Attach suitable lifting chains to the engine (see Lifting

Gearbox to engine bolts

Wire Assembly, service tool 892/00836 in Service

8.7

Engine mounting bolts

Tools). Take the weight of the engine on the hoist.

Note: The engine oil pressure switch, water temperature

Loosen and remove the engine mounting bolts S (both

switch and water temperature sensor torque figure varies

sides).

depending on the material it is screwed into.

Lift the engine clear of the machine.

Kgf m

lbf ft

Plastic

0.4

3.0

Put the engine on a suitable stand, the correct

Aluminium

3.0

dismantling and assembly procedures are detailed in

the Engine Service Manual, publication number

9806/0100.

9803/3280

Issue 1

JCB 3CX, 4CX, 214e, 214, 215, 217 & VARIANTS Backhoe Loader. Service Manual - page 33