This document provides a summary of key information from a service manual for compact excavators. It discusses the exhaust system, including components like the inlet manifold, outlet manifold, and catalyst. The inlet manifold distributes air to the cylinders, while the outlet manifold collects exhaust gases. The catalyst converts toxic pollutants in exhaust to less toxic substances. The document provides descriptions, diagrams, and procedures for inspecting and removing/installing these components. Safety precautions are also outlined when working with exhaust gases and hot parts.

1. SERVICE MANUAL
COMPACT EXCAVATOR
45Z-1, 48Z-1, 51R-1
EN - 9813/6400 - ISSUE 2 - 07/2018
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
27 - Driveline
30 - Hydraulic System
33 - Electrical System
72 - Fasteners and Fixings
75 - Consumable Products
78 - After Sales

2. 18 - Fuel and Exhaust System
24 - Exhaust
00 - General
18 - 77 9813/6400-2 18 - 77
00 - General
Introduction .................................................... 18-77
Health and Safety .......................................... 18-78
Component Identification ............................... 18-79
Check (Condition) .......................................... 18-81
Introduction
The exhaust system is used to guide exhaust gases
away from the controlled combustion inside the
engine by means of an exhaust pipe. Depending
on the machine design, the exhaust gas may flow
through the following components:
• Cylinder head and exhaust manifold.
• Turbocharger to increase the engine power (if
installed).
• A catalytic converter or EGR (Exhaust Gas
Recirculation) system to reduce air pollution (if
installed).
• SCR (Selective Catalytic Reduction) (if
installed). In SCR system exhaust gases
pass through the DEF (Diesel Exhaust Fluid)
injection chamber to lower the NOx (Nitrogen
Oxide) concentration in the exhaust gases.
• A silencer or muffler to reduce noise (if
installed).
The exhaust pipe carries the toxic and noxious gases
away from the users of the machine. Note machines
or generators that work indoors can quickly fill an
enclosed space with carbon monoxide or other
poisonous exhaust gases if they are not properly
vented to the outdoors.

3. 18 - Fuel and Exhaust System
24 - Exhaust
00 - General
18 - 78 9813/6400-2 18 - 78
Health and Safety
Exhaust Gases
Machine exhaust gases can harm and possibly kill
you or bystanders if they are inhaled. Do not operate
the machine in closed spaces without making sure
there is good ventilation. If possible, install an
exhaust extractor. If you begin to feel drowsy, stop
the machine at once and get into fresh air.
Sparks
Explosions and fire can be caused by sparks from
the exhaust or the electrical system. Do not use the
machine in closed areas where there is flammable
material, vapour or dust.
Hazardous Atmospheres
This machine is designed for use in normal out
door atmospheric conditions. It must not be used
in an enclosed area without adequate ventilation.
Do not use the machine in a potentially explosive
atmosphere, i.e. combustible vapours, gas or dust,
without first consulting your JCB dealer.
Hot Components
Touching hot surfaces can burn skin. The engine and
machine components will be hot after the unit has
been running. Allow the engine and components to
cool before servicing the unit.
WARNING! The engine has exposed rotating parts.
Switch off the engine before working in the engine
compartment. Do not use the machine with the
engine cover open.

4. 18 - Fuel and Exhaust System
24 - Exhaust
00 - General
18 - 79 9813/6400-2 18 - 79
Component Identification
Table 117. Intake and exhaust circuit
Air in intake.
Gas in recycle.
Gas in exhaust.
Figure 460. Typical circuit
4
5
6
7
3
E
D
C
8
F
B
10
11
2
1
1 Air in intake from air filter 2 Air in compression
3 Air in inter cooler flow 4 Air cooling
5 Air in intake manifold flow 6 Air in head intake
7 Air in cylinder intake 8 Gas in cylinder outlet
10 Gas in outlet towards catalyst 11 Gas in oxidation
B Exhaust manifold C Upper crankcase

5. 18 - Fuel and Exhaust System
24 - Exhaust
00 - General
18 - 80 9813/6400-2 18 - 80
D Lower crankcase E Oil sump
F Catalyst
Figure 461. Typical circuit
G
11
12
13
14
A
15
6
9
6 Air in head intake 9 Gas in head outlet
11 Gas in oxidation 12 Gas in recycle towards EGR valve
13 Gas in EGR valve outlet 14 Gas cooling (in EGR cooler)
15 Exhaust gas recirculation into intake manifold A Intake manifold
G Radiator

6. 18 - Fuel and Exhaust System
24 - Exhaust
00 - General
18 - 81 9813/6400-2 18 - 81
Check (Condition)
Excessive smoke from the exhaust stack combined
with a complaint of low power could be as a result of:
• Dirt or dust (unfiltered air) ingested directly into
the engine, resulting in damage to the cylinder
bores, there will also be a possible increase in
oil consumption.
• Air leaks from the air hose connections.
• Exhaust manifold leaks.

7. 18 - Fuel and Exhaust System
24 - Exhaust
03 - Inlet Manifold
18 - 82 9813/6400-2 18 - 82
03 - Inlet Manifold
Introduction .................................................... 18-82
Check (Condition) .......................................... 18-83
Remove and Install ....................................... 18-83
Introduction
On compression ignition (diesel) engines, the inlet
manifold (also called the intake manifold) is the
part of the air intake system that distributes air for
combustion to the cylinders via each inlet port in
the cylinder head. The design of the manifold is
important to make sure that air is distributed as
evenly as possible under all engine speed and load
conditions.

8. 18 - Fuel and Exhaust System
24 - Exhaust
03 - Inlet Manifold
18 - 83 9813/6400-2 18 - 83
Check (Condition)
1. Check the manifold mating faces for signs of
damage and distortion.
2. Check the manifold casting for signs of cracks.
3. Renew the manifold if there are any signs of
defect.
Remove and Install
NOTE: The illustrations shown are for a 4 cylinder
engine however, the 3 cylinder engine also has a
similar configuration.
Before Removal
1. This procedure requires service parts. Make
sure you have obtained the correct service parts
before you start, refer to Parts Catalogue.
2. Make sure that the engine is safe to work on. If
the engine has been running, let it cool before
you start the service work.
3. Remove the EGR (Exhaust Gas Recirculation)
cooler.
4. Remove the TMAP (Temperature Manifold Air
Pressure) sensor.
Remove
Front Intake Manifold
1. Remove the screw to loosen the clamp that
secures the coolant hose between the oil cooler
and water pump.
Figure 462.
D
C
E
A
B
A Front Intake manifold
B Screw
C Clamp
D Coolant hose
E Water pump
2. Remove the screws to open the front intake
manifold.
3. Remove the two gaskets and the separation
plate from the front intake manifold.

9. 18 - Fuel and Exhaust System
24 - Exhaust
03 - Inlet Manifold
18 - 84 9813/6400-2 18 - 84
Figure 463.
G
F
A
H
A Front intake manifold
G Gasket (x2)
H Separation plate
Rear Intake Manifold
1. Remove the screw that attaches the holder to the
rear intake manifold.
Figure 464.
K
J
J Screw
K Holder
2. Remove the screws to loosen the clamp of the
high pressure fuel pipe.
3. Remove the screws that attach the rear intake
manifold to the cylinder head.
4. Remove the rear intake manifold with its gasket.
Figure 465.
L
M
QN
P
L Screw
M Clamp
N Screw
P Rear intake manifold
Q Gasket
5. Put protective covers on the open ports of the
cylinder head.
6. Inspect the intake manifolds for any damage.
Replace if damaged.
Refer to: PIL 18-24-03.
Install
Rear Intake Manifold
1. Remove the protective cover from the open ports
of the cylinder head.
2. Install the intake manifold mounting studs to align
the holes on the cylinder head with the rear intake
manifold.
3. Put the rear intake manifold and the gasket in
position against the cylinder head.
4. Install the screws to attach the rear intake
manifold to the cylinder head.

10. 18 - Fuel and Exhaust System
24 - Exhaust
03 - Inlet Manifold
18 - 85 9813/6400-2 18 - 85
Figure 466.
R
Q
N
R
P
N Screw
P Rear intake manifold
Q Gasket
R Mounting stud
5. Tighten the screws to the correct torque value.
6. Install the screws to attach the holder to the rear
intake manifold.
7. Tighten the screws to the correct torque value.
8. Install the screws to attach the clamp of the high
pressure fuel pipe.
Figure 467.
M
K
L
J
J Screw
K Holder
L Screw
M Clamp
9. Tighten the screws to the correct torque value.
Front Intake Manifold
1. Put the two gaskets and the separation sheet in
position on the intake manifold mounting studs.
2. Make sure you install the separation plate
between the two gaskets.
3. Put the front intake manifold in position against
the mounting studs.
4. Put the screws into the front intake manifold.
Figure 468.
A
G
F
R
G
H
A Front intake manifold
G Gasket
H Separation plate
R Mounting stud
5. Make sure that you leave the holes shown open
for the EGRcooler and the coolant hose clamp.
Figure 469.
S
S
S Screw holes for EGR cooler and coolant hose
clamp
6. Tighten the screws to the correct torque value.
7. Install the screw on the clamp that secures the
hose between the oil cooler and water pump.
Figure 470.
D
C
E
A
B
A Front Intake manifold
B Screw
C Clamp
D Coolant hose
E Water pump

11. 18 - Fuel and Exhaust System
24 - Exhaust
03 - Inlet Manifold
18 - 86 9813/6400-2 18 - 86
After Installation
1. Install the TMAP sensor.
2. Install the EGR cooler.
Table 118. Torque Values
Item Nm
F 23
J 6
L 6
N 23

12. 18 - Fuel and Exhaust System
24 - Exhaust
04 - Outlet Manifold
18 - 87 9813/6400-2 18 - 87
04 - Outlet Manifold
Introduction .................................................... 18-87
Component Identification ............................... 18-88
Check (Condition) .......................................... 18-89
Remove and Install ....................................... 18-90
Introduction
The exhaust outlet manifold collects the exhaust
gases from the multiple cylinders and delivers it to
the turbocharger or the exhaust pipe.

13. 18 - Fuel and Exhaust System
24 - Exhaust
04 - Outlet Manifold
18 - 88 9813/6400-2 18 - 88
Component Identification
The exhaust manifold collects the exhaust gases
from the multiple cylinders and deliver it to the
exhaust pipe.
Figure 471.
A
C
B
A Outlet manifold B Fixing bolts
C Manifold gasket

14. 18 - Fuel and Exhaust System
24 - Exhaust
04 - Outlet Manifold
18 - 89 9813/6400-2 18 - 89
Check (Condition)
1. Check the manifold mating faces for signs of
damage and distortion.
2. Check the manifold casting for signs of cracks.
3. Renew the manifold if there are any signs of
defect.
4. Visually inspect for leaks at the exhaust manifold.
Make sure all gaskets are in good condition,
replace as required.

15. 18 - Fuel and Exhaust System
24 - Exhaust
04 - Outlet Manifold
18 - 90 9813/6400-2 18 - 90
Remove and Install
NOTE: The illustrations shown are for a 4 cylinder
engine however, the 3 cylinder engine also have a
similar configuration.
Remove
1. Make sure that the engine is safe to work on. If
the engine has been running, let it cool before
you start the service work.
2. Get access to the exhaust manifold.
3. Remove the turbocharger.
4. Remove the nuts that attach the exhaust
manifold to the cylinder head. Discard the nuts.
5. Remove the exhaust manifold and its metal
gaskets.
6. Discard the gaskets.
7. Put protective covers on the cylinder
head openings and manifolds to prevent
contamination.
Figure 472.
A
C
B
A Exhaust manifold B Self locking nut (x10)
C Gasket (x5)

16. 18 - Fuel and Exhaust System
24 - Exhaust
04 - Outlet Manifold
18 - 91 9813/6400-2 18 - 91
Install
Important: Replace the metal gaskets between the
manifold and the cylinder head every time they are
removed.
1. Remove the protective covers from the cylinder
head and manifolds.
2. Make sure that the contact surfaces of the
cylinder head and manifolds are clean.
3. Put the metal gaskets on the cylinder head studs.
4. Put the exhaust manifold on the studs.
5. Apply Loctite 242 on the studs.
6. Install the self locking nuts to secure the exhaust
manifold.
7. Tighten the nuts to the correct torque value.
8. Install the turbocharger.
Table 119. Torque Values
Item Nm
B 25

17. 18 - Fuel and Exhaust System
24 - Exhaust
18 - Catalyst
18 - 92 9813/6400-2 18 - 92
18 - Catalyst
Introduction .................................................... 18-92
Component Identification ............................... 18-93
Operation ....................................................... 18-94
Check (Condition) .......................................... 18-95
Remove and Install ....................................... 18-95
Introduction
The catalytic converter also called a catalyst is a
vehicle emissions control device that converts toxic
pollutants in exhaust gas to less toxic pollutants by
catalyzing a reaction (oxidation or reduction).

18. 18 - Fuel and Exhaust System
24 - Exhaust
18 - Catalyst
18 - 93 9813/6400-2 18 - 93
Component Identification
Figure 473.
D
C
B
A
A Turbine housing with Wastegate valve B Catalyst support flange
C Gasket D Catalyst

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20. 18 - Fuel and Exhaust System
24 - Exhaust
18 - Catalyst
18 - 94 9813/6400-2 18 - 94
Operation
The catalytic converter consists of a monolith
honeycomb substrate coated with platinum group
metal catalyst. This honeycomb structure is then
covered in a stainless steel container.
The honeycomb structure with many small parallel
channels presents a high catalytic contact area
to exhaust gases. As the hot gases contact the
catalyst, several exhaust pollutants are converted
into harmless substances.
The diesel oxidation catalyst is designed to oxidize
carbon monoxide, gas phase hydrocarbons, and the
Soluble Organic Fraction (SOF) of diesel particulate
matter to CO2 and H2O:
Figure 474.
Diesel exhaust contains sufficient amounts of
oxygen, necessary for the above chemical reactions.
The concentration of O2 in the exhaust gases from
diesel engine varies between 3 –17 %, depending
on the engine load.
The catalyst activity increases with temperature. A
minimum exhaust temperature of about 200 °C is
necessary for the catalyst to "light off". At higher
temperatures, conversions depend on the catalyst
size and design and can be higher than 90 %.
The catalytic oxidation of SOF results in reduction
of diesel particulate matter emission. The particulate
matter conversion efficiency can range widely,
depending on the SOF contents of the particulates
and sulphur level in the fuel.

21. 18 - Fuel and Exhaust System
24 - Exhaust
18 - Catalyst
18 - 95 9813/6400-2 18 - 95
Check (Condition)
A catalyst converter may reach the end of its life
prematurely if on the receiving end of a badly
performing engine. Catalytic converters are free
from moving components and require little to no
maintenance. Therefore, what wears out or damages
a catalytic converter is external and not an issue
caused by the unit itself.
What damages a catalytic converter can vary, but
here's a few examples:
• Out-of-tune engine - Catalytic converters are
designed to work when the engine is running
optimally. This could be due to incorrect fuel
mixture, incorrect engine timing etc. Including
potential damage to the catalytic converter,
such issues may cause damage to the engine
itself.
• Excessive fuel - If your vehicle is using
excessive fuel, it won't get burnt and make your
machine go faster. It's simply unused and re-
routed through the exhaust. As a result, this
unused fuel will enter the catalytic converter.
The converters operate at high temperatures
and can ignite the fuel as it enters, this
renders the catalytic converter at super-hot
temperatures, even causing it to melt down.
• Oil - Oil entering the exhaust will ultimately
travel though the catalytic converter, clogging
the internals of the catalytic converter and
preventing it from working efficiently. This can
cause excessive heat to accumulate within the
converter and other engine components.
• Physical damage - The catalytic converter
being located where it is, can receive damage
from road debris such as rocks. Although the
catalytic converter is protected, a strike from
a heavy piece of debris may damage the
internals.
Important
• Use only the specified fuel. Low S.A.P.S.
technology (fuel with low Sulphate,
Phosphorous, Sulphur content) keeps catalyst
in working conditions. The presence of sulfate,
phosphorus and sulfur ashes causes with
time the catalyst clogging and its consequent
inefficiency.
• Do not run the engine at idle for more than 10
min.
Remove and Install
Remove
1. Make sure that the engine is safe to work on. If
the engine has been running, let it cool before
you start the service work.
2. The catalyst can be hot even after the engine has
cooled. Make sure that the catalytic converter is
fully cooled even if the engine has cooled.
3. Remove the nuts and bolt that attach the catalyst
to the front exhaust pipe.
Figure 475.
A
B
B C
D
E
E
G
F
A Strap
B Nut (x3)
C Gasket
D Front exhaust pipe
E Bolt
F Catalyst
G Mounting bracket
4. Remove the gasket between the catalyst and the
front exhaust pipe.
5. Loosen the strap of the catalyst from the catalyst
mounting bracket.
6. Remove the nuts that attach the catalyst to the
turbocharger support flange.

22. 18 - Fuel and Exhaust System
24 - Exhaust
18 - Catalyst
18 - 96 9813/6400-2 18 - 96
Figure 476.
F
J
K
H
F Catalyst
H Nut (x3)
J Gasket
K Turbocharger support flange
7. Remove the gasket between the catalyst and the
support flange.
8. Release the strap completely from the catalyst.
9. Carefully remove the catalyst from the engine
with a soft mallet.
10. Remove the thermal blanket from the catalyst.
Install
1. Make sure that the catalyst is clean and not
damaged.
2. Make sure you always use new gaskets.
3. Put the thermal blanket on the catalyst.
4. Put the catalyst in position against the mounting
bracket.
5. Attach the strap. Do not tighten it at this stage.
6. Put the gasket on the support flange studs.
7. Put the catalyst mounting flange on the
turbocharger support flange.
8. Install the nuts to attach the catalyst to the
turbocharger support flange.
9. Put the gasket between the catalyst and the front
exhaust pipe.
10. Attach the front exhaust pipe to the catalyst with
the bolts and nuts.
11. Tighten all of the nuts to the correct torque value.
12. Tighten the strap to the correct torque value.
Table 120. Torque Values
Item Nm
A 10
B 24
H 24