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JCB 3CX, 4CX, 214e, 214, 215, 217 & VARIANTS Backhoe Loader. Service Manual - page 32

Section F

Transmission

Section F

134 - 2

Powershift Gearbox

134 - 2

PS 760 - 2/4WD Clutch (Pressure ON)

- Dismantling

1

Remove bearing 1, only if to be renewed.

2

Carefully remove piston ring seal 2. Note, If the piston

ring seal is damaged or excessively worn then check for

burrs or damage on the shaft groove. If necessary

remove burrs with a fine grade abrasion paper and oil.

3

Using a puller or press, withdraw the 4WD gear and

splined hub 5, together with its bearing 3, needle roller

bearings 6 and thrust washer 4. Remove thrust washer

13

7. (Note that thrust washers 4 and 7 are not

interchangeable).

4

Remove the clutch friction/counter plates retaining

circlip 8.

5

Remove pressure end plate 10 and shim 9, if fitted.

6

Remove the clutch friction plates 11 and counter plates

12. Keep them together in sets, DO NOT mix the plates

A401360

with those from other clutches.

7

Position clutch assembly in a suitable press, with a cut

away tube compress the piston spring as shown, then

remove circlip 13.

8

Lift off spring retaining plate 14.

9

Remove the spring 15 and oil baffle 15A.

10

Turn the assembly over and knock the clutch shaft on a

piece of aluminium (or wood) to loosen the piston 16.

Note: If the piston does not loosen when the clutch shaft is

knocked on aluminium, then hand pump air down the shaft oil

inlet hole.

11

Remove the piston 16. Remove and discard the piston

'O' ring 17 and shaft 'O' ring18.

9803/3280

Issue 1

Section F

Transmission

Section F

134 - 3

Powershift Gearbox

134 - 3

PS 760 - 2/4WD Clutch (Pressure ON) - Assembly

10

9

12

11

7

18

1

3

A

8

2

10

15a

4

6

17

5

15

16

8

14

13

A396260

9803/3280

Issue 2*

Section F

Transmission

Section F

134 - 4

Powershift Gearbox

134 - 4

PS 760 - 2/4WD Clutch (Pressure ON)

- Assembly

Visually inspect the friction and counter plates:

9

Fit thrust washer 7.

Counter plates - light scoring/polishing is permissible,

10

Carefully align the teeth of the clutch plates using a thin

plates that are not flat, worn or heavily marked or

rod (or screwdriver) and fit the 4WD gear and splined

scored must be replaced with a new set.

hub 5, needle roller bearings 6 and thrust washer 4.

Friction plates - the cross hatching should be clearly

11

Smear the clutch end bearing 3 with gearbox oil and

visible, plates that are not flat, have friction material

press the bearing onto the shaft to seat on thrust

damage or scoring must be replaced with a new set.

washer 4.

DO NOT mix old, new and worn plates, if a plate is

12

Fit piston ring seal 2, refer to Piston Ring Seals -

damaged/worn fit a complete new set.

Fitting Procedure.

Needle roller bearings should slide into position freely, do not

bend or distort the cage to fit. If the cage has been distorted

fit new bearings.

Note: The piston incorporates a small check valve. Visually

inspect the piston to ensure the ball is in place and that the

seat is free from contamination. If necessary clean the valve

by blowing through with an air line. DO NOT use a wire rod

(or screwdriver) as damage to the valve seat could occure.

1

Fit new 'O' rings 17 and 18. Lubricate the piston 16 with

oil and press fully into bore of clutch housing.

2

Fit oil baffle 15A, piston spring 15, make sure the spring

seats in the piston.

3

Fit the spring retaining plate 14.

4

Compress the spring and secure with circlip 13.

5

Fit one counter plate 12 followed by one friction plate

11. Continue fitting alternate counter and friction plates,

finishing with a friction plate.

* 6

Fit the pressure end plate 10, do not fit shim 9 at this

stage. Make sure that the chamfered face is fitted

facing the clutch pack as shown at A. Make sure the

teeth are not aligned with the lubrication slots in the

housing.

7

Fit the clutch friction/counter plates retaining circlip 8.

8

Using a dial test indicator as shown, measure the end

float of the pressure end plate 10, which should be 1.9

to 2.5 mm (0.075 to 0.098 in).

If it is necessary to adjust the end float to bring it within

tolerance, there is a choice of fitting a 6.0mm (0.23in) or

6.5mm (0.25in) thick pressure end plate 10, with either a

shim 9 or an extra counter plate 12 between the

retaining circlip 8 and pressure end plate 10.

Use an airline to check the operation of the clutch.

217590

9803/3280

Issue 2*

Section F

Transmission

Section F

150 - 1

Torque Converter

150 - 1

Torque Converter

Removal

See the relevant gearbox removal procedure for torque

11

Rotate the flywheel until the next bolt hole is

converter removal.

accessible, fit and hand tighten the next bolt 3. Repeat

the operation until all bolts are fitted. Finally torque

tighten bolts 3 to 44 Nm (32 lbf ft), rotating the flywheel

Replacing

Ensure that flywheel face, drive plate, and hardware are

each time to align bolts 3 with access hole. Refit

clean and free from burrs or other surface imperfections.

access plate.

When Replacing

1

Offer drive plate 1 to the torque converter.

2

Place the torque converter alignment tool A over the

torque converter spigot, make sure that the tool locates

in two of the converter bolt holes as shown. It is

important to note that the converter drive tube must be

protected against damage or contamination at all times.

3

Fit four of the M10 flanged bolts 2 and torque tighten to

2

A

84 Nm (62 lbf ft). Remove the alignment tool and fit the

remaining two retaining bolts 2.

1

4

Offer the torque converter and drive plate assembly to

the flywheel, bolt the drive plate to the flywheel (use

only 3 bolts). Check the converter run-out as shown at

B, which should not exceed 0.38mm (0.015 in.).

Note: In the unlikely event that the run-out exceeds 0.38 mm

S267910

(0.015 in.), remove the converter and check the spigot for

burrs, remove the drive plate and rotate it 180° on the torque

converter, repeat steps 2 to 4.

5

Remove the torque converter and drive plate assembly

from the flywheel.

6

Install the torque converter with its drive plate assembly

onto the transmission input shaft, make sure that the

dogs on the converter pump drive shaft engage with

the recesses in the pump, also take care not to damage

the oil seal.

B

7

Rotate the engine flywheel so that one bolt hole is in a

six O' clock position.

8

Rotate the torque converter and drive plate assembly

so that one bolt hole is in a six O' clock position.

9

Install the transmission/torque converter assembly to

S161470

the engine. See the relevant gearbox replacement

procedure. It is vitally important that the torque

converter is fitted at the gearbox and engine

flywheel correctly. Failure to locate the converter

correctly will result in damage to the gearbox oil pump

on engine start up.

10

Remove the access plate from the bottom of the engine

flywheel housing and through the access hole fit and

hand tighten one M8 flanged bolt (item 3) in the six 'O'

clock position

9803/3280

Issue 1

Section F

Transmission

Section F

150 - 2

Torque Converter

150 - 2

3

2

1

A265990

9803/3280

Issue 1

Section G

Brakes

Section G

3 - 1

Basic System Operation

3 - 1

Compensating Master Cylinder

Pedals Locked - Compensating Operation

When the brake pedals are pushed down (the brake pedals

are mechanically locked together), actuation of the brake

Description

packs H and H1 is as described in Pedals Locked - Normal

Compensating master cylinders overcome the problem of

Operation. If however, the brakes have not worn equally,

unequal wear between the right and left brake. The units

then the amount of fluid displaced from each master

incorporate both master cylinder and compensating valve.

cylinder will vary and some form of compensation is

required.

Each brake has its own master cylinder A, A1, brake pedals

B, B1, servo units N, N1 and associated pipework. Both

Pedal application moves plungers E down the bores of

master cylinders have one common reservoir C.

master cylinders A and A1. Linings of brake H are brought

into contact before the linings of brake H1 because they

Note: Dual pedal braking is applicable only to 2WS

have not worn as severely.

machines. 4WS machines have a single brake pedal.

If further displacement took place at the linings, brake H

Pedals Locked - Normal Operation

would be applied before brake H1. Therefore master

When the brake pedals are pushed down (the brake pedals

cylinder A begins to compensate for master cylinder A1.

are mechanically locked together), rod D pushes the plunger

E down the bore of the master cylinder. Pressurised oil

Fluid is displaced from A to A1 via bridge pipe M until the

acting on centre valve seal F via valve stem G causes the

pressures are equalised. In this condition both

seal to close off the reservoir supply port. As the plunger

compensating valves are open and both brakes are applied

continues to move down the bore, pressurised oil flows to

evenly.

the brake pack H via service port J and the associated

pipework.

Pedals Unlocked - Normal Operation

When a single brake pedal is pushed down, rod D pushes

Master cylinder A1 operates in the same way to feed brake

the plunger E down the bore of the master cylinder.

pack H1.

Pressurised oil acting on centre valve seal F via valve stem

G causes the seal to close off the reservoir supply port. As

With valve stem G at maximum travel, further movement of

the plunger continues to move down the bore, pressurised

plunger E causes valve K to lift off its seat. Both master

oil flows to the brake pack H via service port J and

cylinders are interconnected via bridge pipe M, therefore

associated pipework, thus braking one wheel only.

hydraulic pressure in both cylinders will be equal.

With valve stem G at maximum travel, further movement of

If the brake packs H and H1 have worn equally, then the

plunger E causes valve K to lift off its seat. Fluid is

amount of oil displacement between cylinders will be

displaced through drillings P from the active cylinder A via

minimal and the brakes will be applied evenly.

bridge pipe M to passive cylinder A1. Valve K1 in the

passive cylinder is held on its seat by the displaced

pressurised fluid.

C

M

N1

H1

A1

B1

H

J

A

K

F

G

D

B

E

P

N

A265570

9803/3280

Issue 1

Section G

Brakes

Section G

20 - 1

Service Procedures

20 - 1

Service Brakes

Brake Light Switch - Adjustment

1

Select the starter key switch to the ON position, do not

start the engine.

2

With the brake pedal in the return position, adjust

locknuts B and use feeler gauges to set the proximity

switch A so that there is clearance of 2mm MIN - 3mm

MAX between the end of the switch and the brake

pedal lever. The light emitting diode (L.E.D.) on the

switch should be illuminated.

3

Secure the switch in position by tightening locknuts B.

4

Depress the brake pedal and check the correct

operation of the brake lights.

Torque Settings

Item

Nm

kgf m

lbf ft

A

B

29

2.95

21

B

B

9803/3280

Issue 1

Section G

Brakes

Section G

20 - 2

Service Procedures

20 - 2

Service Brakes

5

Repeat steps 1 to 4 for the opposite brake piston seal.

6

Reconnect all brake pipes and bleed the brake system.

Brake Piston Seal Leakage Test

Refer to Service Brakes - Bleeding.

The following procedure explains how to check if a brake

piston seal is severely damaged/perished or if the seal has a

small cut or nick. The test must only be done when the axle

is COLD.

! WARNING

X

Before working on the brake system make sure the

machine is on level ground and chock all four wheels.

BRAK 1-4

! WARNING

Do not drive the machine with any part of its brake

system disconnected. When the following test has been

completed reconnect all brake pipes and bleed the brake

system using the recommended procedure.

BRAK 2-1

1

Remove and cap brake piston feed pipe A.

2

Fill the brake piston housing with JCB Light Hydraulic

Fluid.

3

Check for severe piston seal damage:

a Install a hand pump fitted with a 0 - 40 bar (0 - 600

lbf/in²) pressure gauge to port B, as shown at X.

Note: The hand pump MUST be filled with JCB Light

Hydraulic Fluid. DO NOT exceed 69bar (1000 lbf/in²).

159830X

b Use the hand pump to generate a pressure in the

brake piston housing.

c If the pressure falls off rapidly, or if no pressure

reading can be obtained, the seal is severely

Y

damaged and needs replacing with a new one.

4

Check for small cuts or nicks in the piston seal:

a Install an adapter fitted with a piece of clear tube to

the brake piston port B, as shown at Y.

Note: The tube must be kept vertical during the test, use

tape to attach the tube to the side of the machine.

b Fill the tube until approximately three quarters full

with JCB Light Hydraulic Fluid

c Using a suitable pen, mark the level line of the

brake fluid on the tube, as shown at C.

d After approximately 1/2 hour, check if the level has

dropped below the original marked line, if it has

then check the brake piston seal for slight nicks,

cuts or generally for wear.

159830Y

9803/3280

Issue 1

Section G

Brakes

Section G

20 - 3

Service Procedures

20 - 3

Parking Brake - Testing

If you have any queries concerning this test procedure or

SAFETY NOTICE: Ensure all routine health and safety

parking brake adjustment, consult your local JCB distributor.

precautions are observed before operating machines.

! WARNING

! WARNING

Do not use a machine with a faulty parking brake.

Before testing the parking brake make sure the area

3-2-3-10

around the machine is clear of people.

2-2-4-5

! CAUTION

1

Enter the machine. Fasten your seat belt and park the

Non approved modifications to axle ratios, machine

machine on a level dry surface.

weight or wheel and tyre sizes may adversely affect the

performance of the parking brake.

2

Fully apply the parking brake 1.

3-2-3-11

3

On machines with two brake pedals ensure they are

locked together.

6

4

Start the engine and raise the attachments to the

6

appropriate travelling position.

3

P

2

5

Select fourth gear, 2 for syncro shuttle machines or 3

for powershift machines.

5

6

Push down hard on foot brake pedal 4.

1

7

Select forward drive 5.

! WARNING

4

If the machine starts to move during the following test,

immediately apply the foot brakes and reduce the engine

speed.

2-2-5-1

Test the parking brake as follows:

8

Move the parking brake lever fractionally forward until

the warning light 6 is just extinguished.

9

Slowly release the foot brake pedal 4.

10

If the machine has not moved, use the accelerator

pedal to gradually increase the engine speed to 1500

RPM. The machine should not move.

11

Do not do this test for longer than 20 seconds.

A394410

12

Reduce the engine speed to idle and select neutral 5.

13

Return the park brake lever 1 to the fully on position

from its partially applied position.

14

Lower attachments and stop the engine.

15

If the machine moved during this test, adjust the

parking brake and repeat the test. See Service

Procedures, Parking Brake - Adjustment.

9803/3280

Issue 1

Section G

Brakes

Section G

20 - 4

Service Procedures

20 - 4

Parking Brake - Adjustment

Cable Adjustment

! CAUTION

Adjust the cable at the calliper if there is insufficient

The parking brake must not be used to slow the machine

adjustment at the parking brake lever.

from travelling speed, except in an emergency,

otherwise the efficiency of the brake will be reduced.

If there is no adjustment at the lever or the calliper, change

Whenever the parking brake has been used in an

the brake pads, refer to Parking Brake - Renewing the

emergency, always renew both brake pads.

4-2-1-1/2

Brake Pads.

! WARNING

Always renew a worn or damaged cable.

Before working on the parking brake, make sure that the

1

Disengage the parking brake (lever horizontal).

machine is on level ground. Put chocks each side of all

four wheels. Disconnect the battery so that the engine

2

Turn hand grip E anti-clockwise to centre the pin F in its

cannot be started. If you do not take these precautions

slot.

the machine could run over you.

2-3-2-4/1

3

Release the two locknuts at B and adjust the cable

The parking brake should be fully engaged when the lever is

length to give 10 to 15mm (0.40 to 0.60 in) of caliper

vertical. The parking brake indicator light should light when

lever movement at the outer cable fixing hole H. The

the brake is engaged with the forward/reverse lever away

total clearance between the brake pad to brake disc

from neutral (starter switch at IGN).

should be 0.5 to 0.75 mm (0.02 to 0.3 in).

4

Make sure there is adequate freedom of movement of

! WARNING

operating lever C to ensure a positive brake application,

Over adjustment of the parking brake could result in the

and that the lever returns to the rest position when the

parking brake not fully releasing

parking brake is released.

0011

5

Test the parking brake, refer to Parking Brake -

Lever Adjustment

Testing. Make final adjustments at the park brake lever

if the brake fails the test. Refer to Lever Adjustment.

1

Disengage the parking brake (lever horizontal).

2

Turn handle grip E clockwise, half a turn.

3

Test the parking brake, refer to Parking Brake -

Testing.

4

If the brake fails the test, repeat steps 1, 2 and 3. If

there is no more adjustment and pin F is at the end of

B

its travel adjust the cable.

H

B

C

E

F

A390850

A396181

9803/3280

Issue 2*

Section G

Brakes

Section G

20 - 5

Service Procedures

20 - 5

Parking Brake - Switch Adjustment

1

Select the starter key switch to the ON position, do not

start the engine.

2

Select either forward or reverse.

3

Raise the handbrake to the ON position.

4

Adjust locknuts B and use feeler gauges to set the

proximity switch A so that there is clearance of 2mm

MIN - 3mm MAX between the end of the switch and the

handbrake lever. The light emitting diode (L.E.D.) on the

switch should be illuminated and the audible alarm

should sound.

5

Secure the switch in position by tightening locknuts B.

6

Release the parking brake and the audible alarm should

cease.

For adjustment of the Parking Brake, refer to Parking Brake

- Adjustment.

Torque Settings

Item

Nm

kgf m

lbf ft

B

29

2.95

21

B

B

A

A396440

9803/3280

Issue 1

Section G

Brakes

Section G

20 - 6

Service Procedures

20 - 6

Parking Brake - Renewing the Brake Pads

Pad Replacement

1

Fit the pad 2 to the lever side of the calliper. Position

! WARNING

the pad inside housing 15. Locate the plastic clip in the

This is a safety critical installation. Do not attempt to do

centre of the rotor 9 into the hole X, and press the pad

this procedure unless you are skilled and competent to

into place.

do so.

2

Fit the pad 1 to the carrier sde of the calliper. Add a

Installation and mounting of the parking brake calliper

small amount of silicon sealant to the back outer edge

requires tightening of the mounting bolts to a specific

of the backing plate to hold the pad in place within the

torque figure. Do not attempt to do this job unless you

housing.

have the correct tools available.

0010

3

Replace the calliper, refer to Parking Brake - Calliper

! WARNING

Removal and Replacement.

Before working on the parking brake, park on level

ground and put chocks each side of all four wheels. Stop

Note: If there is insufficient adjustment after fitting new pads

the engine and disconnect the battery so that the engine

change the brake cable.

cannot be started. If you do not take these precautions

the machine could run over you.

BRAK 8-8

! WARNING

Brake pads generate dust which if inhaled, may

endanger health. Wash off the calliper before

commencing work. Clean hands thoroughly after work.

13-3-1-3

Pad Removal

1

Remove the parking brake calliper from the axle

mounting bracket, refer to Parking Brake - Calliper

Removal and Replacement.

2

Press carrier side pad 1 into housing 15 and remove.

Ensure any residual silicone used for pad retention

during assembly is removed.

3

Carefully lever pad 2 from the rotor inside the housing

using a flat blade screwdriver. Take care to prevent

damage to the plastic clip in the centre of the rotor 9

(there is no need to remove the rotor from the calliper).

Pad Inspection

! WARNING

Oil on the brake disc will reduce brake effectiveness.

Keep oil away from the brake disc. Remove any oil from

15

the disc with a suitable solvent. Read and understand

the solvent manufacturer’s safety instructions. If the

pads are oily, new ones must be fitted.

2-3-2-3/3

1

The minimum thickness of the friction material on either

pad is 1mm (0.04 in), but it is recommended new pads

X

are fitted as pads worn to this limit may not be able to

be adjusted.

1

2

Check the condition of the disc surface. Renew the disc

2

if badly warped, pitted or worn. For brake disc removal,

refer to Parking Brake, Brake Disc - Removal and

Replacement.

9

A390680

3

Renew the cable if worn or damaged.

9803/3280

Issue 1

Section G

Brakes

Section G

30 - 1

30 - 1

G

F

A396450

B

D

E

H

H

E

J

K

327340

9803/3280

Issue 1

Section G

Brakes

Section G

30 - 3

Master Cylinder and Servo Unit

30 - 3

Dismantling and Assembly

Note 1: The servo unit (not shown) is a non serviceable part.

A faulty servo unit must be replaced with a new one.

Note 2: Seal kits are no longer available for the master

cylinders, the only servicing permitted is a major repair kit

which comprises of a full piston assembly. A faulty master

cylinder and piston assembly must be replaced with new

ones.

Dismantling

Assembly

1

Remove circlip 1 and washer 2.

! WARNING

Use of incorrect fluid will cause serious damage to the

2

Shake the cylinder body, or use compressed air, to

seals which could in turn cause brake failure.

eject piston assembly 3. Take care not to damage the

BRAK 1-1

piston assembly or the bore of the cylinder body.

1

Clean and lubricate all components, including new

3

Examine the working surfaces of piston and cylinder. If

seals, with JCB Special Hydraulic Fluid. DO NOT USE

these are not in perfect condition the master cylinder

CONVENTIONAL BRAKE FLUID OR SERIOUS

assembly must be renewed. The piston assembly 3

DAMAGE WILL BE CAUSED.

cannot be dismantled. If it is damaged (including seal 5),

the complete piston/seal assembly must be renewed,

2

Take care not to damage the machined faces of piston

see Note 2:

assembly 3 when assembling.

S151280

9803/3280

Issue 1

Section G

Brakes

Section G

40 - 1

Service Brakes

40 - 1

Dismantling and Assembly

The service brakes are located in the rear axle, as shown at

A. Instructions for dismantling and assembly of the brake are

described in Section F - Rear Axle Brakes.

A

A264180

9803/3280

Issue 1

Section G

Brakes

Section G

40 - 2

Service Brakes

40 - 2

Bleeding

! WARNING

Before proceeding with the bleeding procedure it is

important to ensure that the parking brake is engaged

and that one pair of wheels is blocked on both sides.

BRAK 1-2

! WARNING

Use of incorrect fluid will cause serious damage to the

seals which could in turn cause brake failure.

BRAK 1-1

1

Fill the master cylinder reservoir with the correct fluid,

refer to Section 3 Fluids, Lubricants, Capacities and

Specifications, and ensure that throughout the

bleeding process the level is not allowed to fall below

the MINIMUM mark.

2

Unlatch the pedals, and bleed each brake separately as

follows:

3

Right Hand Master Cylinder

a Attach a tube to the right hand brake bleed screw

A, ensuring that the free end of the tube is

immersed in fluid contained in a suitable container.

b Open the brake bleed screw and apply full pedal

strokes of the right hand brake pedal until all air is

expelled.

c Close the brake bleed screw with the pedal fully

depressed.

4

Left Hand Master Cylinder

a Repeat procedure as for 'Right Hand Master

Cylinder' but use left hand bleed screw and pedal.

5

Bridge Pipe

a Attach a tube to either the left or right hand brake

bleed screw, ensuring that the free end of the tube

is immersed in fluid contained in a suitable

5

container.

b Make sure that the brake pedals are locked

together.

Note: 4WS machines do not have dual pedal braking. These

machines are fitted with a single pedal that operates both

A

master cylinders.

c Open the bleed screw and apply full pedal strokes

of the brake pedals until all air is expelled.

d Close the bleed screw with the pedals fully

depressed.

6

Repeat the procedures as necessary.

7

Top up the reservoir to the full mark.

S107710-1

9803/3280

Issue 1

Section G

Brakes

Section G

50 - 1

Parking Brake

50 - 1

Torque Figures

The illustration shows a typical installation.

Where appropriate, the grade of bolt is indicated in

parenthesis eg. (10.9). Refer also to relevant dismantling and

assembly procedures.

Torque Settings

Item

Nm

lbf ft

A

166

122

(12.9)

B

13-15

9-12

C

255

188

(10.9 Tuflok)

C

A

A396540

B

9803/3280

Issue 1

Section G

Brakes

Section G

50 - 2

Parking Brake

50 - 2

Calliper Removal and Replacement

Replacement

! WARNING

This is a safety critical installation. Do not attempt to do

Replacement is the reverse of the removal sequence.

this procedure unless you are skilled and competent to

do so.

1

Locate the calliper on the brake disc and fit new

mounting bolts C with hardened washers, torque

Installation and mounting of the parking brake calliper

tighten to 255 Nm (188 lbf ft).

requires tightening of the mounting bolts to a specific

torque figure. Do not attempt to do this job unless you

2

Insert cable into bracket D, do not tighten locknuts B at

have the correct tools available.

this stage as the brake will need adjusting.

0010

! WARNING

*

3

Refit the clevis A into the hole in the operating lever E

Before working on the parking brake, park on level

as shown.

ground and put chocks each side of all four wheels. Stop

the engine and disconnect the battery so that the engine

4

Make sure there is adequate freedom of movement of

cannot be started. If you do not take these precautions

operating lever E to ensure a positive brake application,

the machine could run over you.

and that the lever returns to the rest position when the

BRAK 8-8

parking brake is released.

! WARNING

Brake pads generate dust which if inhaled, may

5

Adjust the parking brake, see Service Procedures,

endanger health. Wash off the calliper before

Parking Brake Adjustment. Never unscrew the

commencing work. Clean hands thoroughly after work.

clevis A to adjust the cable.

13-3-1-3

Removal

Torque Settings

1

Release the parking brake lever (lever horizontal).

Item

Nm

lbf ft

2

Disconnect clevis A, note which of the three holes on

C

255

188

the lever is used.

3

Undo locknuts B and disconnect the cable from the

bracket D.

B

4

Support the calliper and remove the two mounting bolts

and hardened washers C. Lift the calliper and bracket D

clear of the brake disc.

A

B

Note: Do not remove axle mounting bracket F unless it

needs to be renewed.

C

D

E

C

F

A396181

9803/3280

Issue 2*

Section G

Brakes

Section G

50 - 3

Parking Brake

50 - 3

Component Listing:

1

Carrier Side Pad

2

Lever Side Pad

3

Bolt

4

Anti-rotation Clip

5

Washer

6

Washer

7

Lever

8

Spring

9

Rotor

10

Ball Spacer

11

Ball Bearings

12

Mounting Bush

13

O-ring

14

Shaft Seal

15

Housing

228362

9803/3280

Issue 1

1

12

13

2

13

10

7

14

4

9

11

12

13

13

15

6

5

8

3

Section G

Brakes

Section G

50 - 6

Parking Brake

50 - 6

Dismantling and Assembly (cont’d)

Assembly

Before assembly make sure all parts are clean and

serviceable.

1

Fit a new shaft seal 14 if removed. Install the seal as

shown. Press the seal into the housing using a suitable

spacer block and bench press.

2

Coat the the shaft and ball pockets of rotor 9 and the

ball pockets of housing 15 with silicone grease.

Y

3

Insert the three ball bearings 11 into the pockets in the

housing 15. Insert ball spacer 10.

4

Slide rotor 9 through the casting and seat the ball

pockets against the bearings.

5

Position spring 8 over the shaft of rotor 9. Insert the

A348331

large diameter end of the spring into hole X in the face

X

of the housing.

6

Locate the small diameter end of spring 8 around the

outside edge of lever 7 as shown at Y.

7

Fit lever 7. Align the lever to the mark made during

dismantling.

8

Hold the lever against the tension of the spring and fit

washers 6 and 5, and new anti-rotation clip 4. Fit bolt 3

and tighten to 13-16 Nm (9-12 lbf ft).

9

Bend up a tab of the anti-rotation clip that aligns with

one of the flats on the bolt.

10

Fit the new brake pads, refer to Service Procedures -

Parking Brake - Renewing the Brake Pads.

11

Lubricate the O-rings 13 and bushes 12 with silicone

grease. Fit O-rings into the housing and insert mounting

bushes. Wipe off any excess grease.

12

Before fitting the calliper, ensure the lever rotates

smoothly and that the lever side pad 2 returns to the off

position when the lever is released.

13

Refit the brake calliper. Refer to Calliper - Removal

and Replacement.

14

Adjust the parking brake, refer to Service Procedures

- Parking Brake - Adjustment.

Torque Settings

Item

Nm

lbf ft

3

13-16

9-12

9803/3280

Issue 1

Section H

Steering

Section H

1 - 1

Service Tools

1 - 1

Hexagon Spanners for Ram Pistons and End Caps

992/09300

55mm A/F

992/09400

65mm A/F

992/09500

75mm A/F

992/09600

85mm A/F

992/09700

95mm A/F

992/09900

115mm A/F

992/10000

125mm A/F

S191750

892/0018

Seal Fitting Tool for fitting 'O' ring and kin

ring to Hydraulic Steer Unit

S193930

9803/3280

Issue 1

Section H

Steering

Section H

2 - 1

Technical Data

2 - 1

System Type

Full power hydrostatic with selectable 2-wheel, 4-

wheel and crab steer modes on 4 wheel steer

machines.

Oil supply from Main Hydraulic Pump via Priority Valve

to Steer Unit Valve complete with Load Sensing and

Integral Relief Valve.

Double acting power track rod rams mounted on axles.

2 Wheel Steer Machines

STEER UNIT - FIG 1

Model

200 OSPC

- Volumetric Displacement

200 cc/rev

- Relief Valve

Fitted

- Check Valve

Fitted

- Shock Valve

Fitted

- Relief Valve Operating Pressure (at 1500 revs/min)

120 ± 3 bar

122 ± 3.5 kgf/cm²

1740 ± 50 lbf/in²

-Shock Valve Operating Pressure

175 - 190bar 178 - 199 kgf/cm²

2538 - 2756 lbf/in²

Model

250 OSPC

- Volumetric Displacement

250 cc/rev

- Relief Valve

Fitted

- Check Valve

Fitted

- Shock Valve

Not Fitted

- Relief Valve Operating Pressure (at 1500 revs/min)

120 ± 3 bar

122 ± 3.5 kgf/cm²

1740 ± 50 lbf/in²

PRIORITY VALVE - FIG 2

-Stand by Pressure

7 bar

7.1 kgf/cm²

102 lbf/in²

4 Wheel Steer Machines

STEER UNIT - FIG 1

Model

160 OSPC

- Volumetric Displacement

160 cc/rev

- Relief Valve

Fitted

- Check Valve

Fitted

- Shock Valve

Fitted

- Relief Valve Operating Pressure (at 1500 revs/min)

120 ± 3 bar

122 ± 3.5 kgf/cm²

1740 ± 50 lbf/in²

- Shock Valve Operating Pressure

175 - 190bar 178 - 199 kgf/cm²

2538 - 2756 lbf/in²

PRIORITY VALVE - FIG 2

-Stand by Pressure

7 bar

7.1 kgf/cm²

102 lbf/in²

LS

EF

P

LS

LS

A263810

A263820

FIG 1

FIG 2

9803/3280

Issue 1

Section H

Steering

Section H

3 - 1

Basic System Operation

3 - 1

2 Wheel Steer Machines

Steer System Schematics

Component Key:

P1

Pump, Main Section

P2

Pump, Secondary Section

P2A

Pressure Test Point

S

Suction Line

T

Tank

6

In-tank Filter

7

Priority Valve

10

Front Power Track Rod Ram

42

Steer Unit

43

Shock Valve

44

Steer Unit Relief Valve

Note: Hydraulic component port identification letters are

shown in parenthesis, e.g. (LS). The same letters will be

stamped on the actual component.

T

6

43

(L)

(R)

S

42

(LS)

10

P2

P1

(P)

(T)

44

(CF)

(EF)

(LS)

(P)

7

P2A

A263860

9803/3280

Issue 1

Section H

Steering

Section H

3 - 2

Basic System Operation

3 - 2

2 Wheel Steer Machines

Hydraulic Operation

The main components of the steering system are the priority

valve 7, load sensing steer unit 42, hydraulic tank T and the

front power track rod ram 10.

When the steering wheel is turned, a pressure demand is

sensed at the priority valve 7 via load sensing line LS.

Oil from the hydraulic pump P2 is then distributed via the

priority valve to the steer unit 42, which then directs the oil

to the front power track rod ram 10 untill the required

steering lock is achieved.

When the steering lock is held, the pressure signal LS

ceases, flow from the hydraulic pump P2 is now distributed

to the main hydraulic circuit via the priority valve 7.

Maximum steering system pressure is controlled by a relief

valve located in the steering unit 42.

7

7

LS

42

P2

T

10

42

A401110

9803/3280

Issue 1

Section H

Steering

Section H

3 - 3

Basic System Operation

3 - 3

4 Wheel Steer Machines

Steer System Schematics

Component Key:

P1

Pump, Main Section

P2

Pump, Secondary Section

P2A

Pressure Test Point

S

Suction Line

T

Tank

6

In-tank Filter

7

Priority Valve

8

Steer Mode Control Valve

10

Front Power Track Rod Ram

11

Rear Power Track Rod Ram

42

Steer Unit

43

Shock Valve

44

Steer Unit Relief Valve

Note: Hydraulic component port identification letters are

shown in parenthesis, e.g. (LS). The same letters will be

stamped on the actual component.

T

6

10

43

(L)

(R)

S

42

(LS)

8

P2

P1

(T)

(B)

(P)

44

(T)

(P)

(A)

(CF)

(EF)

(LS)

(P)

7

P2A

11

A263850

9803/3280

Issue 1

Section H

Steering

Section H

3 - 4

Basic System Operation

3 - 4

4 Wheel Steer Machines

Hydraulic Operation

The main components of the steering system are the priority

valve 7, load sensing steer unit 42, hydraulic tank T, front

power track rod ram 10 and rear power track rod ram 11.

When the steering wheel is turned, a pressure demand is

sensed at the priority valve 7 via load sensing line LS.

Oil from the hydraulic pump P2 is then distributed via the

priority valve to the steer unit 42.

8

When left turn is selected, oil is distributed from steer unit 42

to the rear power track rod ram 11 via the steer mode

control valve 8. When right turn is selected, oil is delivered

directly to the front power track rod ram 10.

When the steering lock is held, the pressure signal LS

ceases, flow from the hydraulic pump is now distributed to

the main hydraulic circuit via the priority valve 7.

A396570

Maximum steering system pressure is controlled by a relief

valve located in the steering unit 42.

7

7

LS

8

42

P2

T

11

10

42

A401120

9803/3280

Issue 1

Section H

Steering

Section H

3 - 5

Basic System Operation

3 - 5

4 Wheel Steer Machines

B

Electrical Operation

Three steering modes are available:

- 2 Wheel Steer (front axle)

- 4 Wheel Steer

- Crab Steer

The three modes are selected in the cab from a three

position switch A which operates relays in the steer mode

A

control unit B. The relays switch the energising supplies to

the solenoid operated steer mode control valve C. Proximity

E

L1

switches on the front D and rear E axles signal when the

L2

wheels are in the straight ahead position.

C

L3

D

Lights L1, L2 or L3 on the instrument panel illuminate to

indicate the steer mode currently operative.

In 2 wheel steer mode only the front wheels are steered. In 4

wheel steer mode both axles are steered, giving a smaller

A401140

turning circle and so improving manoeuvrability. The crab

steer mode allows the machine to be driven diagonally into

loading/unloading positions which might otherwise be

inaccessible.

The system is prevented from changing mode until the

relevant proximity switch is energised. If, for example, the

system is set in 4 wheel steer and 2 wheel steer is then

selected, the system will stay in 4 wheel steer untill the rear

wheels are turned to the straight ahead position, thus

energising the rear axle proximity switch. The rear wheels

are then hydraulically locked in the straight ahead position.

C

A

E

B

D

A401130

9803/3280

Issue 1

Steer Unit Operation

- 4 Wheel Steer Machines

4 Wheel Steer Mode

- Neutral

Flow from the priority valve enters the steering unit

through the bottom right hand port past the non-

return valve 43C. When the steering wheel is

stationary the inner spool A and sleeve B are held

in the neutral position by the centring springs K. As

the unit is 'closed centre' the flow from the pump is

dead ended by the steering unit.

In 4 wheel steer mode the spools of the steer mode

control valve X are configured as shown.

Component Key:

A Inner Spool

B Sleeve

D Stator

K Centring Springs

X Steer Mode Control Valve

43C Non-Return Valve

A395730

K

Key to Oil Flow & Pressure

Full Pressure

Pressure

Servo

A

Neutral

Exhaust

Cavitation

Lock Up

B

A390630

43C

B

X

D

A395640

Key to Oil Flow & Pressure

Full Pressure

Pressure

Servo

Neutral

A

Exhaust

Cavitation

Lock Up

B

A390630

40

43B

41

LS

B

X

D

A395650

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