service repair manual

1. SERVICE MANUAL
LOADER
403
EN - 9813/4200 - ISSUE 3 - 06/2018
This manual contains original instructions, verified by
the manufacturer (or their authorized representative).
Copyright 2018 © JCB SERVICE
All rights reserved. No part of this publication may
be reproduced, stored in a retrieval system, or
transmitted in any form or by any other means,
electronic, mechanical, photocopying or otherwise,
without prior permission from JCB SERVICE.
www.jcb.com
Foreword
The Operator's Manual
You and others can be killed or seriously injured
if you operate or maintain the machine without
first studying the Operator's Manual. You must
understand and follow the instructions in the
Operator's Manual. If you do not understand
anything, ask your employer or JCB dealer to
explain it.
Do not operate the machine without an Operator's
Manual, or if there is anything on the machine you
do not understand.
Treat the Operator's Manual as part of the machine.
Keep it clean and in good condition. Replace the
Operator's Manual immediately if it is lost, damaged
or becomes unreadable.
Contents
01 - Machine
03 - Attachments, Couplings and Load
Handling
06 - Body and Framework
09 - Operator Station
12 - Heating, Ventilating and Air-
Conditioning (HVAC)
15 - Engine
18 - Fuel and Exhaust System
21 - Cooling System
24 - Brake System
25 - Steering System
27 - Driveline
30 - Hydraulic System
33 - Electrical System
72 - Fasteners and Fixings
75 - Consumable Products
78 - After Sales

2. 24 - Brake System
00 - Brake System
00 - General
24 - 3 9813/4200-3 24 - 3
00 - General
Health and Safety ........................................... 24-3
Technical Data ................................................. 24-4
Component Identification ................................. 24-5
Operation ......................................................... 24-6
Adjust .............................................................. 24-7
Bleed ............................................................... 24-9
Disassemble and Assemble .......................... 24-10
Health and Safety
Brake Fluid
Use of incorrect brake fluid will cause serious
damage to the seals of the braking system. This will
result in brake failure.
Accumulators
The accumulators contain hydraulic fluid and gas at
high pressure. Prior to any work being carried out
on systems incorporating accumulators, the system
pressure must be discharged by a JCB dealer, as
the sudden release of the hydraulic fluid or gas may
cause serious injury or death.
Service Brake Bleeding
Before bleeding the service brake system, park on
level ground and set the park brake to on. Put blocks
on both sides of the wheels on one axle to prevent
the machine rolling. Stop the engine and disconnect
the battery so that the engine cannot be started. If
you do not take these precautions the machine could
run over you.
Park Brake Maintenance
Before working on the park brake, park on level
ground and put blocks on both sides of all wheels
to prevent the machine rolling. Stop the engine and
disconnect the battery so that the engine cannot be
started. If you do not take these precautions the
machine could run over you.
Working Under the Machine
Make the machine safe before getting beneath it.
Make sure that any attachments on the machine are
correctly attached. Engage the park brake, remove
the ignition key, disconnect the battery. If the machine
has wheels use blocks to prevent unintentional
movement.
Brake Dust
Brake pads generate dust, which if inhaled may
endanger health. Wash off the caliper assemblies
before commencing work. Clean hands thoroughly
after completing the work.
Brake Dust
Brake shoes generate dust, which if inhaled
may endanger health. Make sure that dust is
removed correctly, particularly before installing
new components. Clean hands thoroughly after
completing the work.
Springs
Always wear personal protective equipment when
dismantling assemblies containing components
under pressure from springs. This will protect against
eye injury from components accidentally flying out.
Notice: Using incorrect fluid could damage the
system. See Fluids, Capacities and Lubricants for

3. 24 - Brake System
00 - Brake System
00 - General
24 - 4 9813/4200-3 24 - 4
the correct fluid. The fluid can harm your skin. Wear
rubber gloves. Cover cuts or grazes.
WARNING! Before working on the brake system,
make sure that the machine is on solid level ground.
Put blocks on all wheels to prevent the machine
rolling.
WARNING! Do not use the machine with any part of
its brake system disconnected or inoperative. When
the test has been completed, make sure all brake
system components are installed and the system is
operating correctly.
WARNING! Before testing the park brake make sure
the area around the machine is clear of people.
WARNING! If the machine starts to move during the
park brake test, immediately apply the foot brake and
reduce the engine speed.
WARNING! If the machine starts to move during the
service brake test, immediately reduce the engine
speed and apply the park brake.
WARNING! Do not use a machine with a faulty park
brake.
WARNING! Non approved modifications to drive
ratios, machine weight or wheel and tyre sizes may
adversely affect the performance of the park brake.
WARNING! Oil on the brake disc will reduce brake
effectiveness. Keep oil away from the brake disc.
Remove any oil from the disc with a suitable solvent.
Read and understand the solvent manufacturer's
safety instructions. If the pads are oily, install with the
new pads.
WARNING! Faulty brakes can kill. If you have to top
up the brake oil reservoir frequently, get the brake
system checked by your JCB Dealer. Do not use the
machine until the fault has been put right.
WARNING! The park brake must not be used to
slow the machine from travelling speed, except in an
emergency, otherwise the efficiency of the brake will
be reduced. Whenever the park brake has been used
in an emergency the brake friction components must
be renewed and the other components inspected.
Notice: Over adjustment or failure to disengage the
park brake properly will cause excessive wear of the
park brake mechanism.
Technical Data
Table 43. Brake Shoes Wear Limit
Type Wear Limit
Riveted brake shoes 1.5 mm above rivet head
at thinnest point of the
lining.
Glued brake shoes 2 mm at thinnest point of
the lining.
Table 44. Brake drum Wear/Machining Limit
Diameter When New Wear/Machining Limit
203 mm 204.5 mm

4. 24 - Brake System
00 - Brake System
00 - General
24 - 5 9813/4200-3 24 - 5
Component Identification
Figure 161.
C
E
H
J
GF
A
B
D
A Brake pedal B Park brake lever
C Brake master cylinder D Brake fluid tank
E Foot brake inching cable F Swing arm
G Return spring H Brake line
J Master cylinder to front axle hose

5. 24 - Brake System
00 - Brake System
00 - General
24 - 6 9813/4200-3 24 - 6
Operation
The brake is operated by pressing the foot pedal
which is connected to the master cylinder. Brake fluid
is forced from the master cylinder into the wheel
cylinder which pushes two brake shoes against the
drum. One brake shoe, (primary brake shoe) is taken
in the direction of rotation of the brake drum. The
second brake shoe, (secondary brake shoe) aligned
by the floating power transmission of the automatic
adjustment unit, is blocked against a fixed point at
the top of the brake back plate or the wheel cylinder.
By the supplementary force of the primary shoe,
the so-called “self-energization” (servo effect) of the
brake is generated. The braking efficiency is almost
the same in both directions.
When the brake pedal is released the tension springs
overcome the pressure in the wheel cylinder forcing
brake fluid to return to the reservoir and pulling the
brake shoes away from the brake drum.
Figure 162.
C
C
A
B
D
E
A Wheel cylinder
B Back plate
C Brake shoes
D Automatic adjustment unit (with protective
cover)
E Tension springs
The brake incorporates an automatic adjustment unit
in order to maintain correct clearance between the
brake shoes and the brake drum.
The washer actuates the adjustment lever downward
until it skips one or more teeth of the adjustment
wheel, depending on the required adjustment
distance. When the brake is released, the adjustment
lever is returned to the neutral position (horizontal)
by the force of the compression spring, turning the
adjustment wheel one or more teeth further. The
adjustment pin is screwed out by the thread of the
adjustment wheel, adjusting the brake shoe to brake
drum clearance.
Figure 163.
1
2
D
D
F
F
G
G
H
HJ
J
K
K
1 Actuated brake
2 Released Brake
D Automatic adjustment unit
F Washer
G Adjustment lever
H Adjustment wheel
J Compression spring
K Adjustment pin

6. 24 - Brake System
00 - Brake System
00 - General
24 - 7 9813/4200-3 24 - 7
Adjust
The brake assembly incorporates an automatic
adjuster that maintains the correct clearance
between the brake shoes and the brake drum.
Adjustment is only required after component
replacement.
1. Make the machine safe.
Refer to: PIL 01-03.
2. If necessary raise and support the machine
safely.
3. Release the park brake. Make sure that the
machine is prevented from moving.
4. Disconnect the park brake cable.
5. Remove the propshaft.
Refer to: PIL 27-47-00.
6. Remove the brake drum and the brake shoes.
Refer to: PIL 24-00-00.
7. Carefully lift up the adjustment lever with a
suitable tool so that the adjustment wheel can
easily be turned.
Figure 164.
C
B
B
C
A
A Adjustment lever
B Adjustment wheel
C Adjustment pin
8. Turn the adjustment wheels until the dimension
'a' is at the specified distance.
Length/Dimension/Distance: 60 mm
Figure 165.
b b
a
a Dimension 'a'
b Dimension 'b'
8.1. Make sure that the dimensions 'b' are
symmetrical.
9. Install the brake shoes.
Refer to: PIL 24-00-00.
10. Turn the adjustment wheels until the dimension
'c' is at the specified distance.
Length/Dimension/Distance: 201.8 ± 0.2 mm
10.1. Exact adjustment of the shoe position is
of critical importance for the operation
of the automatic adjustment unit. If the
adjustment is too small, this could result in
damage to the adjustment unit.
Figure 166.
D D
c
c Dimension 'c'
D Brake shoes
11. Connect the park brake cable.
11.1. The park brake cable must not be pre-
tensioned as this will prevent proper
operation of the automatic adjustment unit.

7. 24 - Brake System
00 - Brake System
00 - General
24 - 8 9813/4200-3 24 - 8
12. Install the brake drum.
Refer to: PIL 24-00-00.
12.1. The brake drum should be able to rotate
freely.
13. Loosen the mounting bolt for the automatic
adjustment unit.
Figure 167.
E
GF
E Bolt
F Brake back plate
G Automatic adjustment unit
14. Operate the brake several times using either the
service brake or the park brake to make sure
that the brake shoes and adjustment unit are
centered in the brake drum.
15. Tighten the bolt to the correct torque value.
16. Install the propshaft.
Refer to: PIL 27-47-00.
17. If necessary, lower the machine.
18. Perform 10 braking actions using the service
brake in forward and reverse directions. Do not
use hard braking force.
Table 45. Torque Values
Item Nm
E 53

8. 24 - Brake System
00 - Brake System
00 - General
24 - 9 9813/4200-3 24 - 9
Bleed
1. Make the machine safe. Refer to (PIL 01-03).
2. Chock the wheels.
3. Make sure that the fluid level is maintained above
the minimum level.
4. Install bleed pipe to the bleed screw of the brake.
5. Loosen the bleed screw.
6. Fully stroke the brake pedal at a controlled rate
of approximately 50 mm/sec.
7. Close the bleed screw.
8. Fully release the brake pedal at a controlled rate
of approximately 50 mm/sec.
9. Open the bleed screw.
10. Do steps 6 to 9 ten times or until there are no air
bubbles visible in the brake fluid return line.
11. Tighten the bleed screw to the specified torque
value.
Torque: 2.5 –4 N·m
12. Check the brake pedal travel. Refer to (PIL
24-03).
13. Fill the tank with brake fluid up to the maximum
level.
14. Recharge the brake system.
Figure 168.
A
A Bleed screw

9. 24 - Brake System
00 - Brake System
00 - General
24 - 10 9813/4200-3 24 - 10
Disassemble and Assemble
Special Tools
Description Part No. Qty.
Clamping device 334/D2062 1
Disassemble
1. Make the machine safe. Refer to (PIL 01-03).
2. Remove the front axle from the machine. Refer
to (PIL 27-20).
3. Identify the brake unit installed on your machine.
4. Mount the axle on a suitable stand.
Hydraulic Servo Brake
1. Remove the plastic protection caps.
Figure 169.
2. Use a screwdriver or a suitable adjusting tool to
turn back the adjuster unit.
Figure 170.
3. Loosen the cylindrical screws (x2).
4. Remove the brake drum.
Figure 171.
5. Loosen the bolt connection.
Figure 172.
5.1. Use the specified tool to remove the flange.
Special Tool: Clamping device (Qty.: 1)
5.2. The bolted connection is secured with
Loctite.
6. Remove all compression and tension springs.
7. Remove the brake shoes.

10. 24 - Brake System
00 - Brake System
00 - General
24 - 11 9813/4200-3 24 - 11
Figure 173.
A
A
A
A
A
A Tension springs
7.1. Make sure that the tappet with compression
spring and washer does not fall down.
8. Remove the park brake cable.
Figure 174.
A
A Brake cable
9. Loosen the bolts from the brake anchor plate
connection.
10. Remove the brake anchor plate assembly.
Figure 175.
11. Loosen the bolted connection.
12. Remove the brake carrier.
Figure 176.
12.1. Remove the shaft seal ring from the brake
carrier.
Assemble
Hydraulic Servo Brake
1. Install the shaft seal with a suitable plate.

11. 24 - Brake System
00 - Brake System
00 - General
24 - 12 9813/4200-3 24 - 12
Figure 177.
Figure 178.
BA
A Plate
B Shaft seal
1.1. Apply spirit to the contact face of the shaft
seal.
1.2. Apply grease type PETAMO GHY 133 on
the shaft seal in the area of the dust lip and
sealing lip.
2. Apply grease to the O-ring.
3. Install the O-ring to the axle drive housing.
4. Install the brake carrier.
5. Install the cylindrical screws.
Figure 179.
5.1. Tighten the cylindrical screws to the correct
torque value.
Torque: 125 N·m
6. Install the pre-assembled brake anchor plate with
cylindrical screws.
Figure 180.
6.1. Tighten the cylindrical screws to the correct
torque value.
Torque: 115 N·m
7. Install the cable on the bracket of the brake shoe.

12. 24 - Brake System
00 - Brake System
00 - General
24 - 13 9813/4200-3 24 - 13
Figure 181.
8. Position the brake shoe and install it with
compression spring (hold-down device).
Figure 182.
9. Position the tappet.
10. Install the compression spring and washer.
Figure 183.
10.1. Make sure that the installation position
of tappet is correct. The bend must face
upwards.
11. Position the second brake shoe correctly.
12. Install the brake shoe with the compression
spring.
Figure 184.
12.1. Install the tappet with compression spring
and washer.
13. Interlock both tension springs in the brake shoes
and install them on the spring holder.
Figure 185.
13.1. Install the lower tension spring.
14. Install the stud bolts into the flange.

13. 24 - Brake System
00 - Brake System
00 - General
24 - 14 9813/4200-3 24 - 14
Figure 186.
14.1. Tighten the stud bolts to the correct torque
value.
Torque: 17 N·m
15. Install the flange.
16. Install the washer and the new locknut.
Figure 187.
16.1. Tighten the locknut to the correct torque
value.
Torque: 450 N·m
17. Install the brake.
18. Install the cylindrical screws.
Figure 188.
18.1. Tighten the cylindrical screws to the
correct torque value.
Torque: 9.5 N·m
19. Adjust the setting of the adjuster unit. Refer to
(PIL 24-00).
Figure 189.

14. 24 - Brake System
03 - Service Brake
01 - Master Cylinder
24 - 17 9813/4200-3 24 - 17
01 - Master Cylinder
Adjust ............................................................ 24-17
Remove and Install ....................................... 24-18
Adjust
1. Make the machine safe. Refer to (PIL 01-03).
2. Remove any unwanted materials from the cab
floor.
3. Remove the floor mats (if installed). Refer to (PIL
09-48).
4. Remove the brake pedal guard. Refer to (PIL
06-06-13).
5. Remove the pin and disconnect the push rod
from the bell crank.
6. Lift the pedal to the off position so that the stop on
the inching bell crank hits the base plate. Refer
to Figure 190.
7. Make sure that the pedal is at the specified angle
to the floor.
Angle: 42 °
8. Make sure that the braking bell crank is at the
bottom of the inching slot. Refer to Figure 191.
Figure 190.
A
A Bell crank stop
9. Adjust the push rod by turning the nut so that the
holes on the bell crank and the push rod line up.
10. Tighten the nut.
11. Insert the pin through the hole.

15. 24 - Brake System
03 - Service Brake
01 - Master Cylinder
24 - 18 9813/4200-3 24 - 18
Figure 191.
B
E CG D
F
B Pedal
C Nut
D Master cylinder
E Pin
F Inching slot
G Push rod
Remove and Install
Remove
1. Make the machine safe. Refer to (PIL 01-03).
2. Chock the machine wheels.
3. Release the pressure in the brake system. Refer
to (PIL 24-00).
4. Put a container under the brake master cylinder
to collect the brake fluid.
5. Put a label on the pipes to help installation.
6. Disconnect the brake pipes from the brake
master cylinder.
7. Plug all the open ports and pipes to prevent
contamination.
8. Remove and discard the split pin from the pin
that attaches the master cylinder clevis to the bell
crank.
9. Remove the pin that attaches the master cylinder
clevis to the brake pedal.
10. Remove the nut 3, bolt and washers.
11. Remove the brake master cylinder.

16. 24 - Brake System
03 - Service Brake
01 - Master Cylinder
24 - 19 9813/4200-3 24 - 19
Figure 192.
A
B
CE DGF
A Brake pipes
B Nut 1
C Nut 2
D Master cylinder
E Pin attaching clevis to bell crank
F Bolt
G Nut 3
Install
1. The installation procedure is the opposite of the
removal procedure. Additionally do the following
steps.
2. Tighten the nut 1 and nut 2 to the specified torque
value.
3. Tighten the nut 3 to the correct torque value.
4. Adjust the brake pedal. Refer to (PIL 24-00).
5. Bleed the brake system. Refer to (PIL 24-00).
6. Check for any leaks in the system.
Table 46. Torque Values
Item Description Nm
B Nut 1 20–24
C Nut 2 7–10

17. 24 - Brake System
18 - Park Brake
06 - Cable
24 - 21 9813/4200-3 24 - 21
06 - Cable
Check (Condition)
1. Make the machine safe.
Refer to: PIL 01-03-27.
2. Inspect the part brake cable to check where it is
secured.
2.1. If part brake cable is secured on the hose,
remove the cable tie.
Figure 193.
2.2. Secure the cable to the adaptor to prevent
the cable from fouling on the hose.
Figure 194.

18. 25 - Steering System
00 - Steering System
00 - General
25 - 3 9813/4200-3 25 - 3
00 - General
Introduction ...................................................... 25-3
Health and Safety ........................................... 25-4
Component Identification ................................. 25-5
Operation ......................................................... 25-6
Check (Pressure) ............................................ 25-6
Introduction
The steering is controlled by the hydraulic system
and the main hydraulic pump. There is a single steer
ram that articulates the front chassis in the required
direction.
A pressure relief valve is installed to guard against
shock steering loads.
The steer valve provides pressure for steering in the
event of hydraulic pump or engine failure.

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20. 25 - Steering System
00 - Steering System
00 - General
25 - 4 9813/4200-3 25 - 4
Health and Safety
Engine/Steering Failure
If the engine or steering fails, stop the machine as
quickly as possible. Do not operate the machine until
the fault has been corrected.
Fluid Under Pressure
Fine jets of fluid at high pressure can penetrate the
skin. Keep face and hands well clear of fluid under
pressure and wear personal protective equipment.
Hold a piece of cardboard close to suspected
leaks and then examine the cardboard for signs of
fluid. If fluid penetrates your skin, get medical help
immediately.
Hydraulic Pressure
Hydraulic fluid at system pressure can injure you.
Before connecting or removing any hydraulic hose,
residual hydraulic pressure trapped in the service
hose line must be vented. Make sure the hose
service line has been vented before connecting or
removing hoses. Make sure the engine cannot be
started while the hoses are open.

21. 25 - Steering System
00 - Steering System
00 - General
25 - 5 9813/4200-3 25 - 5
Component Identification
Figure 195.
D
C
B
A
E
A Steering wheel B Steering column
C Steer unit / valve D Steering hydraulic hoses
E Steering ram

22. 25 - Steering System
00 - Steering System
00 - General
25 - 6 9813/4200-3 25 - 6
Operation
Hydraulic oil is delivered from the hydraulic pump
to the steer unit/valve. When the steering wheel is
turned the steer valve is actuated and a pressure
demand signal is sent to the priority valve spool. The
spool moves and directs the pressurised oil from the
pump to the steer valve and then to the steering ram.
Pressurised oil enters the ram cylinder and causes
the ram to extend or retract to turn the machine in the
required direction.
Check (Pressure)
Special Tools
Description Part No. Qty.
Pressure Gauge (0-400
Bar)
892/00279 1
1. Make the machine safe. Refer to (PIL 01-03).
2. Turn the steering wheel to the left and to the right
several times to discharge the steering system
pressure.
3. Remove the seat base to access gear pump.
Refer to (PIL 09-12).
4. Connect a suitable pressure gauge to the test
adaptor on the hydraulic gear pump.
Special Tool: Pressure Gauge (0-400 Bar) (Qty.:
1)
Figure 196. For machines with 28cc pump
A
A Test adaptor
Figure 197. For machines with 40cc pump
A
A Test adaptor
5. Run the engine at maximum speed to get the
hydraulic oil to its normal operating temperature,
then turn the steering wheel to the full lock
position.
6. Check the reading on the pressure gauge.

23. 25 - Steering System
00 - Steering System
00 - General
25 - 7 9813/4200-3 25 - 7
7. Make sure that the reading on the pressure
gauge is as specified.
Pressure: 165 bar ( 2,391.3 psi)
8. If necessary, adjust the steering pressure.
8.1. Lift the gaiter from the steering column to
access the adjusting screw.
8.2. Use an Allen key to adjust the screw
until the correct pressure is shown on the
pressure gauge.
8.3. Clockwise to increase pressure,
Anticlockwise to decrease pressure.
Figure 198.
C
B
B Steering gaiter
C Adjusting screw