Holset HE851

Service Repair Manual

Copyright 2007, Cummins Turbo Technologies Ltd. All rights reserved.

VGT, Command Valve and Super MWE are trade marks of Cummins Turbo Technologies Ltd.
Holset and the Holset Logo are registered trade marks of Cummins Turbo Technologies Ltd.
Cummins and the Cummins logo are registered trade marks of Cummins Inc.
HE851 Service Manual Foreword

Foreword
This publication was written to assist with turbocharger installation, maintenance and overhaul. It is not a
warranty of any kind expressed or implied.

The specifications and procedures in this manual are based on information in effect at the time of publication.
Holset Service reserves the right to make any changes at any time without obligation. If differences are found
between your turbocharger and the information in this manual, contact your local Holset approved agent.

The latest technology and the highest quality standards are used in the manufacture of Holset Turbochargers.
When replacement parts are needed, we recommend using only genuine Holset parts.
HE851 Service Manual Table of Contents

Table of Contents
1: Introduction
About the Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1:1
How to Use the Manual. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1:1
How to Order Holset Original Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1:1
Description and Operation of Turbocharger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1:2
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1:2
Introduction to Turbocharger Matching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1:2
Notes, Cautions and Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1:3
Installation Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1:4
Installation Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1:5
Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1:6

2: Component Identification
Turbocharger Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2:1
Dataplate and CHRA (Core) of Turbocharger . . . . . . . . . . . . . . . . . . . . . . . . . 2:1
Installation Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2:2
Exploded Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2:4
Component List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2:6

3: Troubleshooting and Diagnosis

Fault Finding Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3:1

4: Component Testing and Replacement

Service Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4:1
On Engine Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4:2
Bearing Clearance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4:6
Turbine and Compressor Housings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4:7
Cleaning of Housings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4:14
Speed Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4:16
Safe Lifting Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4:18

6: Service Data Sheets

HE Range Service Data Sheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6:1
HE851 Service Manual Introduction

About the Manual

The procedures in this manual were developed to instruct in the correct overhaul of the designated
turbochargers for optimum performance and minimum maintenance operation.

How to Use the Manual

The manual is split into sections designed to provide service information in a logical sequence. The manual
contains links to help the user navigate between relevant sections. Users who are unfamilier with navigating in
PDF documents are refered to Navigating in PDF documents in the Adobe® Acrobat® Reader™ help file.

Contents is an interactive page with links to all the sections. It can be accessed from any page
in the manual by clicking this icon.

Section 1 defines the layout of the manual, introduces the reader to the operation of the turbocharger
and presents important installation guidelines.

Sections 2, 3 and 4 concentrate on Turbocharger Component Identification, Troubleshooting and

Diagnosis, Component Testing and Replacement.

Section 5 identifies the Service and Overhaul procedures to be followed in the unlikley event of a
major turbocharger malfunction. (This section is not available for this product at date of issue).

Section 6 quantifies build data to ensure the turbocharger will continue to operate to Holset Service
standard on completion of overhaul.

Manual sections 1 to 5 where applicable, appear as a self extracting compressed file which is organised
according to the steps needed to most easily and correctly maintain the operation of the turbocharger. Users
are required to download this file to hard disk. Section 6 has its own file identity and resides at
www.holset.co.uk. so that Holset can update the Service Data as changes occur. The links between manual
and service data are active only when the user is connected to the Internet.

Chapter 6 has an expiry date to encourage users to discard outdated saved or printed versions and always
access the latest information available at www.holset.co.uk.

When using the manual on-line this icon will link to Holset’s website to help find your nearest agent
for advice and how to order Holset original parts.

How to Order Holset Original Parts

*
To make sure of optimum performance, certain items must be discarded during disassembly and replaced with
new for re-assembly. These items are indicated in the Service and Overhaul section with the use of a

*
symbol.
All items showing a are available in a basic overhaul kit.

To get the correct parts for your turbocharger, refer to the ‘component identification’ section of this manual to
help you find the following information:

1) Refer to the exploded view and component list to define the major components to be replaced.
2) Refer to the turbocharger’s dataplate which will be found on the compressor cover or wastegate
actuator to define the identifying information about your turbocharger build standard.
3) Contact your local Holset agent with componant identification nos. and dataplate assembly no., serial
no. and turbocharger type.
4) With this information, your local agent can provide you with the optimum kit of parts for re-assembling
your turbocharger for continued long life operation.

1:1
HE851 Service Manual Introduction

Description and Operation of Turbocharger

General Information
A turbocharger is a mechanical device which uses the engine’s exhaust gases to force more air into the engine
cylinders. Hot exhaust gas energy is used to turn a turbine wheel and shaft. At the other end of the shaft is the
compressor impeller (or compressor wheel), which draws in air and forces it into the engine cylinders.
Supplying increased air mass flow to the engine provides improved engine performance, lower exhaust smoke
density, improved operating economy and altitude compensation. The turbocharger has proven to be one of the
most beneficial devices for improving engine performance. It performs its job very well, as long as it is properly
cared for.

Introduction to Turbocharger Matching

The need for optimised matching over the engine speed range
A standard turbocharger can be perfectly matched to only one particular engine condition, eg maximum torque
speed or maximum load speed. At this engine speed, the turbocharger supplies the optimum mass of air to
give the required air/fuel ratio. At other speeds the air/fuel ratio cannot be held at the optimum hence fuel
consumption and emission levels worsen.
Engine emission legislations have forced manufacturers to improve their engine efficiencies, particularly at low
speeds where low air/fuel ratios cause high smoke levels.
The Holset turbocharger is carefully matched to meet the required engine characteristics during application
engineering. It is important that this match is maintained by using only Holset original turbine and compressor
parts.

The importance of correctly servicing the turbocharger

A turbocharger requires accurate assembly at point of manufacture. It is very important to adhere to setting
limits when servicing the turbocharger, as failure to do so could result in turbocharger or engine failure.

Effects of wrong match

Possible consequences if turbocharger boost pressure is too low:-
• Engine runs fuel rich • Fuel consumption increase
• Exhaust temperature increase • Smoke levels increase
• Hydrocarbon levels increase • Risks of failing emissions tests
• High cylinder temperature risks
damage to engine pistons

Possible consequences if turbocharger boost pressure is too high:-

• Engine runs fuel weak (lean) • Nitrous oxide levels increase
• Excessive boost overspeeds • Turbocharger bearing failure and
turbocharger wheel fatigue problems
• Increased cylinder pressure risks damage • Intercooler load increases causing engine
to engine head gasket, pistons and valves to overheat, risking piston damage

1:2
HE851 Service Manual Introduction

Notes, Cautions and Warnings

Notes, Cautions and Warnings are used in this manual to emphasise important or critical instructions.
Note
Information which is essential to highlight.

Caution
Maintanence or Service procedures which if not strictly followed, will result in damage or destruction of the
turbocharger.

Warning
Maintanence or Service procedures which if not correctly followed will result in personal injury or loss of life.

Note
Holset turbochargers can be remanufactured using recovered parts. Where it is necessary to dispose of
components or whole turbochargers, an environmentally responsible process such as recycling should be
used, with due regard to local laws.

Note
Holset Service receives many turbocharger returns that are no fault found. Before assuming the turbocharger
is not performing to specification always refer to the engine diagnostic system and the troubleshooting
diagnostic procedures of this manual.

Warning
Turbocharger surface temperature during operation can achieve 700°C (1300°F). The designated
turbochargers weigh up to 60 kg (132 lb) and turbine housing weight is greater than 20 kg (45 lb).

Caution
This turbocharger requires a unique balancing process available through an approved Holset agent.
It is important to note that operating a turbocharger with a rotor or core balance level greater than the
published limits could cause turbocharger or engine failure. If you are in any doubt regarding the balancing
process, please contact an approved Holset agent for assistance.

Warning
Some parts are manufactured in fluoroelastomers (e.g. Viton) or similar that requires special treatment in the
case of repair and service after fire.

1:3
HE851 Service Manual Introduction

Installation Data
1. Holset Service receives many turbocharger returns that are no fault found. Before assuming the
turbocharger is not performing to specification always refer to the engine diagnostic system and the fault
finding chart of this manual to make all the recommended health checks.
2. It is important that intake and exhaust systems are fitted in accordance with the recommendations of the
Equipment and Engine manufacturers. It is important not to overload the turbocharger by external
attachments or forces.
3. The air filter must remove particles greater than 5 µm at an efficiency of 95% and be of sufficient capacity
to match the air consumption of the engine. Recommended filters should always be used with a pressure
drop indicator. Intake systems must be tightened to the values specified by the Equipment and Engine
manufacturers to withstand depressions up to 6.3 kPa (0.91 lbf/in2)
4. Hose and clip connections of the intake manifold system must be tightened to the values specified by the
Equipment and Engine manufacturers to withstand turbocharger pressure ratio.
5. Exhaust system connections must be tightened to the values specified by the Equipment and Engine
manufacturers to be capable of operating at exhaust back pressures of up to 10 kPa (1.5 lbf/in2).
Subject to an extensive review by Holset and formal approval, this limit may be increased to 25 kPa
(3.6 lbf/in2) if a catalytic convertor is fitted. Exhaust brake applications are permitted to operate at a
continuously rated pressure up to 450 kPa (65.3 lbf/in2) Holset has experience of instantaneous
pressures up to 700 kPa (101.5 lbf/in2) but any application operating above 450 kPa (65.3 lbf/in2) must be
referred to Holset for approval.
6. Oil should be filtered to 10 µm with efficiency of 60% TWA (Time Weighted Average) /20 µm with
efficiency of 85% TWA. Efficiency assessed using ISO Standard 4572/SAE J 1858. Always use filters
recommended by the engine manufacturer.
7. The oil quality must be as specified by the engine manufacturer and will be a minimum API SE - CD
(MIL - L - 2104C) specification. Improved life can be obtained by using super high performance diesel
(SHPD) oils, particularly where extended oil drain periods are used.
8. Normal oil temperature is 95+/-5°C (203+/-9° F). It should not exceed 120°C (248° F) under any operating
condition.
9. Any pre-lube oil must be clean and meet the minimum CD classification.
10. The orientation of turbine housing, bearing housing and compressor cover is fixed according to
application. During installation, do not attempt to rotate these components. Inclined turbocharger
installation is not recommended. If an installed angle is necessary, oil inlet centreline must be +/- 10
degrees from vertical and rotor centreline +/- 5 degrees from horizontal.
11. Holset permits oil return pipes to decline at an overall angle of not less than 30 degrees below horizontal.
All turbocharger applications require a pipe of internal diameter greater than 25 mm which has
integrated connectors. To ensure oil returns into the engine under all operating conditions, the return
connection into the engine sump must not be submerged and the outlet flange of the turbocharger must
be 50 mm above the maximum oil level of the engine sump pan.
12. Crankcase pressure should be limited to 0.8 kPa (0.12 lbf/in2). Pressure above this level should be
referred to Holset for further evaluation. Closed crankcase ventilation (CCV) systems are known to
operate at elevated pressure and all applications must be referred to Holset for approval.
13. Oil pressure of 150 kPa (20 lbf/in2) must show at the oil inlet within 3 - 4 seconds of engine firing to
prevent damage to turbocharger bearing system. A flexible supply pipe is recommended. Recommended
oil pressure at full load/ rated speed is 300 kPa (44 lbf/in2) although 600 kPa (88 lbf/in2) is permitted
during cold start up. Under idling conditions pressure should not fall below 70 kPa (10 lbf/in2).
14. Recommended oil flows for the turbochargers are 3.5 litre/min at idleand a minimum of 6 litre/min
above maximum torque speed.
15. Do not use liquid gasket substances or thread sealant as any excess can enter the turbocharger oil
system to obstruct flow.
16. Recommended coolant flows for the turbochargers are 6 litre/min at idle and 13 - 19 litre/min above
maximum torque speed.
Note:
100 kPa = 1 bar (14.5037 lbf/in2 =psi).

1:4
HE851 Service Manual Introduction

Installation Checklist
1. Always understand why the original turbocharger needs replacing before fitting another unit.
2. Check the turbocharger dataplate to ensure the Part No. is correct for the engine/application.
3. Check the engine exhaust, intake and aftercooler systems are clean and without obstruction i.e. free from
oil, gasket pieces, dust/dirt/carbon or foreign objects.
4. Replace the oil and air filters using replacement parts specified by the equipment manufacturer.
5. Change the engine oil using the type specified by the engine manufacturer.
6. Check that the turbocharger oil inlet and drain pipes and connectors are clean, free from obstruction and
will not leak under pressure. Before re-installing flexible pipes always ensure any burnt -on lacquer or other
adhered material is removed from internal bores. If in doubt, fit new pipes.
7. Check that the coolant pipes of water cooled bearing housing applications and connectors are clean, free
from obstruction and will not leak under pressure.
8. To pre-lube the turbocharger bearings, pour some clean engine oil into the oil inlet and rotate the
turbocharger rotor assembly by hand.
9. Check that the exhaust manifold flange is flat and undamaged. Mount the turbocharger on the flange and
check that the turbine inlet gasket fits properly without obstructing the gas passages.
10. Assemble the air intake and boost outlet connections. Check that the connections are well made and will
not leak in use.
11. Check the exhaust system is fitted using the original mounting arrangement provided by the equipment
manufacturer. Always re-fit any supports/brackets back in position to ensure the system is correctly
supported.
12. Assemble the exhaust system to the turbine housing outlet. Check that the gasket/connection is well made
and will not leak in use.
13. Assemble any coolant pipes and check that the connections are well made, without obstruction and will
not leak in use.
14. Assemble the turbocharger oil inlet pipe and check that the connection is clean, well made and will not
leak in use.
15. Check all clamps and fasteners are correctly tightened to the torque recommended by the equipment
manufacturer.
16. Make any ECU checks recommended by the engine manufacturer.
17. Crank the engine WITHOUT firing until engine oil flows out of the turbocharger drain flange.
18. Assemble the oil drain pipe and check that the connection is well made, without obstruction and will not
leak in use.
19. Start the engine and run at idle speed for approximately 1 minute so that the oil supply system is fully
operational.
20. Accelerate the engine and check that there are no leaks/obstructions of air/oil/coolant/gas under pressure.
21. Check that no hose or connection deforms under normal operation.
22. Before switching off the engine, leave it running at idle speed for at least 1 minute to cool the turbine.

1:5
HE851 Service Manual Introduction

Symbols
Symbole - Deutsch
In diesem Handbuch werden die folgenden Symbole verwendet, die wesentliche Funktionen hervorheben. Die
Symbole haben folgende Bedeutung:
WARNUNG - Unterhaltungs und Wartungsverfahren müssen genau befolgt werden, da ein
Nichtbeachten zu Personenschäden oder tödlichen Verletzungen führt.
ACHTUNG - Falls Unterhaltungs und Wartungsverfahren nicht genau beachtet werden, kann der
Turbolader dadurch beschädigt oder zerstört werden.

AUSBAU bzw. ZERLEGEN.

EINBAU bzw. ZUSAMMENBAU.

INSRPEKTION erforderlich.

Teil oder Baugruppe REINIGEN.

DIMENSION - oder ZEITMESSUNG.

Teil oder Baugruppe ÖLEN.

WERKZEUGGRÖSSE wird angegeben.

ANZUG auf vorgeschriebenes Drehmoment erforderlich.

Sicherstellen, daß die AUSWUCHTMARKEN an der Rotor-Baugruppe richtig ausgerichtet sind.

Elektrische MESSUNG DURCHFÜRHREN.

Weitere Informationen an anderer Stelle bzw. in anderen Handbüchern.

Schutzkleidung muß immer getragen werden.

Deutet an, daß Teile schwer sein können.

KG

Website-Verzeichnis mit Ihrem nächsten Holset-Händler.

Gehe zu Inhalt

1:6
HE851 Service Manual Introduction

Symbols - English
The following group of symbols have been used in this manual to help communicate the intent of the
instructions. When one of the symbols appears, it conveys the meaning defined below.
WARNING - Serious personal injury or extensive property damage can result if the warning
instructions are not followed.
CAUTION - Minor personal injury can result or a part, an assembly or the engine can be damaged if
the caution instructions are not followed.

Indicates a REMOVAL or DISASSEMBLY step.

Indicates an INSTALLATION or ASSEMBLY step.

INSPECTION is required.

CLEAN the part or assembly.

PERFORM a mechanical or time MEASUREMENT.

LUBRICATE the part or assembly.

Indicates that a WRENCH or TOOL SIZE will be given.

TIGHTEN to a specific torque.

Ensure that the BALANCE MARKS on the rotor assembly are in alignment

PERFORM an electrical MEASUREMENT.

Refer to another location in this manual or another publication for additional information.

Please wear protective clothing at all times.

Indicates components may be heavy.

KG

Website access to find your nearest Holset Agent.

Go to contents

1:7
HE851 Service Manual Introduction

Simbolos - Español
Los simbolos siguientes son usados en estes manual para clarificar el proceso de las instrucciones. Cuado
aparece uno de estos simbolos, su significado se espcifica en la parte inferior.
ADVERTENCIA – Procedimientos de Mantenimiento o Servicio que al no seguirse resultarán en
daños personales o pérdida de vida.
ATENCION – Procedimientos de Mantenimiento o Servicio que al no seguirse al pie de la letra,
resultarán en el daño o la destrucción del turbosobrealimentador.

Indica un paso de REMOCION o DESMONTAJE.

Indica un paso de INSTALACION o MONTAJE.

Se requiere INSPECCION.

LIMPIESE la pieza o el montaje.

Ejecutese una MEDICION mec·nica o del tiempo.

LUBRIQUESE la pieza o el montaje.

Indica que se dar· una LLAVE DE TUERCAS o el TAMA—O DE HERRAMIENTA.

APRIETESE hasta un par torsor especifico.

Ceriórese de que est·n alineadas las marcas de balance en el rotor.

EJECUTESE una MEDICION eléctrica.

Para información adicional refiérase a otro emplazamiento de este manual o a otra publicación
anterior.

Favor de siempre llevar ropa protectora.

KG
Indica que los componentes pueden ser pesados.

Acceso a Sitio Web para localizar su agente Holset más cercano.

Ir a la tabla de materias

1:8
HE851 Service Manual Introduction

Symboles - Français
Les symboles suivants sont utilisés dans ce manuel pour aider à communiquer le but des instructions. Quand
l’un de ces symboles apparait, il évoque le sens défini ci-dessous:
ATTENTION DANGER - Procédures de maintenance ou d’entretien qui, si elles ne pas observées
correctement, auront pour résultat des lésions corporelles ou un décès.
MISE EN GARDE - Procédures de maintenance ou d’entretien qui, si elles ne sont pas observées
strictement, auront pour résultat de causer des dégâts au turbocompresseur ou de conduire à sa
destruction.
Indique une opération de DEPOSE.

Indique une opération de MONTAGE.

L’INSPECTION est nécessaire.

NETTOYER la pièce ou l’ensemble.

EFFECTUER une MESURE mécanique ou de temps.

GRAISSER la pièce ou l’ensemble.

Indique qu’une DIMENSION DE CLE ou D’OUTIL sera donnée.

SERRER à un couple spécifique.

S’assurer que les repères d’équilibrage sur l’ensemble de rotor sont alignés.

EFFECTUER une MEASURE électrique.

Se reporter à un autre endroit dans ce manuel ou à une autre publication pour obtenir des
information plus complètes.
Il faut toujours mettre vêtements de protection.

KG Indique que les composants peuvent être lourds.

Accès au site Web pour trouver l’agent Holset le plus proche.

Aller au sommaire

1:9
HE851 Service Manual Introduction

Símbolos - Português
Os símbolos a seguir serão utilizados neste manual para facilitar a comunicação das instruções e seue
significados estão déscritos abaixo.
ATENÇÃO - Os procedimentos de Manutenção ou Serviços que não forem seguidos correctamente
resultarão em ferimentos pessoais ou riscos de vida.
AVISO - Os procedimentos de Manutenção ou Serviço que não forem rigorosamente seguidos
resultarão em danos ou destruição do carregador turbo.

Indica um passe de DESMONTAGEM.

Indica um passo de MONTAGEM.

Requer inspeção.

LIMPE a peça ou conjunto.

Requer Medição mecãnica ou de tempo.

LUBRIFIQUE a peça ou o conjunto.

Indica necessidade de APERTO.

TORQUEAR de acordo com o especificado.

Assegure-se de que as MARCAS DE BALANCEAMENTO do conjunto eixorotor estejam alinhadas.

Requer medição ELÉTRICA.

Procure em outra seção deste manual ou em publicação par obter informações adicionais

Por favor, sempre utilize EPI (Equipamento de Protecao Individual)

Indica que os componentes podem estar pesados.

KG

Visite o Website para encontrar o seu Agente Holset mais perto.

Vá para Conteúdo

1:10
HE851 Service Manual Component Identification

Turbocharger Identification
Dataplate
XXXXXXX
PYYMMXXXXX

Note
Dataplates will be fitted to the compressor housing
(8). The information from the dataplate must be
quoted for service and parts support.

Center Housing Rotating Assembly (CHRA) (2)

2:1
HE851 Service Manual Component Identification

Installation Options
Type A

Type B

Type C

2:2
HE851 Service Manual Component Identification

Installation Options
Type D

Type E

2:3
HE851 Service Manual Component Identification

Exploded View - HE851

With speed sensor

96
164
29 62

112

57
50 114

34
22 103

27

53

41
5

71

Note
Compressor housing, wheel, diffuser and V-band are manufactured utilising special materials.
Exploded views represent a generic build standard. Parts may be added or subtracted in specific applications.

2:4
HE851 Service Manual Component Identification

Exploded View - HE851

Housing options

103

27

71

Note
Compressor housing, wheel, diffuser and V-band are manufactured utilising special materials.
Exploded views represent a generic build standard. Parts may be added or subtracted in specific applications.

2:5
HE851 Service Manual Component Identification

Component List - HE851

Item No. Description Quantity
2 CHRA (Core) 1
5 Turbine Housing 1
8 Compressor Housing 1
22 Retaining Ring, Inlet Baffle 0/1
29 V-band Clamp, Compressor 1
164 Spacer Sleeve, V-Band * 1
96 Screw, V-band * 1
62 Locknut, V-band* 1
34 Inlet Baffle 0/1
41 O-Ring Seal, Compressor Housing* 0/1
50 Lockplate, Turbine Housing* 4
53 Gasket, Oil Outlet* 1
57 Bolt, Turbine Housing* 8
71 Gasket, Turbine Housing 1
103 Blanking Plug 0/4
112 Speed Sensor* 0/1
114 O-Ring Seal, Oil Inlet 1
115 O-Ring Seal, Water 0/4

Note
Exploded views may not contain all listed components.

2:6
HE851 Service Manual Troubleshooting and Diagnosis

Fault Finding chart - All Applications

Cyclic Sound from the Turbocharger

Oil Leak from Compressor Seal

Oil Leak from Turbine Seal

Poor Transient Response

High Oil Consumption

Black Exhaust Smoke

Blue Exhaust Smoke

Engine Lacks Power
Engine Running Hot

Turbocharger Noisy
Smoke
Dirty air cleaner
Clean or replace element according to manufacturer s recommendations
Restricted compressor intake duct
Remove restriction or replace damaged parts as required
Restricted air duct from compressor to intake manifold
Remove restriction or replace damaged parts as required
Restricted intake manifold
Refer to engine manufacturer s manual and remove restriction
Air leak in feed from air cleaner to compressor
Replace seals, gaskets or tighten fasteners as required
Air leak in feed from compressor to intake manifold
Replace seals, gaskets or tighten fasteners as required
Air leak between intake manifold and engine
Refer to engine manufacturer s manual and replace gaskets or tighten fasteners as required
Foreign object in exhaust manifold (from engine)
Refer to engine manufacturer s manual and remove obstruction
Restricted exhaust system
Remove restriction or replace damaged parts as required
Exhaust manifold cracked, gaskets blown or missing
Refer to engine manufacturer s manual and replace gaskets or damaged parts as required
Gas leak at turbine inlet/exhaust manifold joint
Replace gasket or tighten fasteners as required
Gas leak in ducting after turbine outlet
Refer to engine manufacturer s manual and repair leak
Restricted turbocharger oil drain line
Remove restriction or replace damaged parts as required
Restricted engine crankcase breather
Refer to engine manufacturer s manual, clear restriction
Turbocharger bearing housing sludged or coked
Change engine oil and oil filter, overhaul or replace turbocharger as required
Fuel injection pump or fuel injectors incorrectly set
Refer to engine manufacturer s manual and replace or adjust faulty components as required
Engine valve timing incorrect
Refer to engine manufacturer s manual for correct settings and adjust as required
Worn engine piston rings or liners
Refer to engine manufacturer s manual and repair as required
Burnt valves and/or pistons
Refer to engine manufacturer s manual and repair as required
Excessive dirt build up on compressor wheel and/or diffuser vanes
Clean in accordance with details in the appropriate Holset publication
Turbocharger damaged
Find and correct cause of failure, repair or replace turbocharger as necessary

3:1
HE851 Service Manual Troubleshooting and Diagnosis

Fault Finding chart - Speed Sensor

Low power at low engine speed

Engine does not run smoothly
Intermittent engine braking

Intermittent low power

Engine Lacks Power

Turbocharger noisy
Engine Overheats

Poor acceleration

Reduced braking

Coolant leak

Oil leak
No speed signal
Check sensor connections. If pin resistance measurement is incorrect replace sensor.
Where sensor may have been overheated check ECU diagnostic fault codes and if
necessary replace sensor.
Intermittent or noisy speed signal
Check sensor with multimeter. If either resistance measurement is incorrect replace
sensor. Where sensor may have been overheated check ECU diagnostic fault codes and
if necessary replace sensor.

3:2
HE851 Service Manual Component Testing and Replacement

Service Tools
The following special tools are recommended to perform procedures in this manual. The use of these tools is
shown in the appropriate procedure.
Part No. Tool Description Tool Illustration

Torque Wrench

Dial Gauge and Dial Gauge Adaptor -0+

10 10

TYPE 20
20 20

30 30
MERCER

40 40
50

Speed Sensor Socket

Rubber Bung

6 mm Allen Key
5/8 in Allen Key

Caution
All Service and Maintenance settings are shown in Holset’s Service Data Sheet. It is essential that these
settings are used. Common tools found in mechanic’s tool box not included.

4:1
HE851 Service Manual Component Testing and Replacement

On Engine Checks
Oil Leakage
Oil Adapter M16 x 1.5 or 9/16 18 UNF 28 tpi

Warning
Always wear safety glasses.

Replacement gaskets, seals and adapters should be

fitted without sealant as this can contaminate the oil.
Torque tighten adapter to value shown in
Service Data Sheet.
It is important to avoid kinked pipes during servicing
and subsequent operation.

Oil Flanges M10 x 1.5 or 3/8-16 UNC 28 tpi

Warning
Inlet oil is pressurized and outlet oil is hot. Never take
service action with engine running. Protect face and
hands from hot fluid leakage.

Replacement gaskets and flange fasteners should be

fitted without sealant as this can contaminate the oil.
Torque tighten fasteners to value specified by engine
manufacturer.
All outlet pipes should be free flowing without kinks and
sharp bends and decline at overall angle not less than
30° below the horizontal.

Warning
Turbochargers and installation parts are heavy.
KG

Always use safe lifting methods.

Closed crankcase ventilation systems tend to deposit
oil in the compressor housing. Where practical remove
intake system pipework every 2000 hours to check
housing, compressor wheel and inlet baffle condition.

Always refer to Cleaning of Housings. Rotor

components can be cleaned using a non metallic bristle
brush. to clean housing. Rotor components can be
cleaned using a non metallic bristle brush.

Warning
Titanium compressor wheel edges are sharp.
Handle with care.

4:2
HE851 Service Manual Component Testing and Replacement

Warning
Always wear safety glasses.

Caution
Use special socket to tighten speed sensor to torque
specified in Service Data Sheet.

In event of an oil leak, refer to Speed Sensor for all

maintenance procedures.

Caution
Where fitted, ensure speed sensor and cable are not
damaged when correcting coolant or oil inlet leak.
Always use engine manufacturer’s cable route and
clips.

Coolant Leakage
Coolant Plug 1 1/16 UN-2A (5/8 in Allen Key)
Repair by replacement of coolant inlet and outlet
fittings. Where housing threads are damaged replace
turbocharger. Torque tighten adapters to value specified
by engine manufacturerer.

Warning
Turbochargers and installation parts are heavy.
Always use safe lifting methods.

Caution
KG

Do not use sealant as this may affect performance of

o-ring seals.

4:3
HE851 Service Manual Component Testing and Replacement

1 5/16 UN-2A (5/8 in)

Warning
Always wear safety glasses.

Warning
If there is any possibility that an o ring seal has been
subject to fire, always wear neoprene gloves when
handling.

Caution
Turbine housing plugs are fitted with an o ring seal.
Always always use parts recommended by engine
manufacturer or Holset.

In event of coolant leakage from plug or adapter, re-

tighten to values specified in Service Data Sheet. If
leak persists change fitting.

Gas Leakage
Turbine housing flange leakage will cause soot
formation on the flange. Check exhaust manifold to
flange gasket seal ensuring fastener torque meets
engine manufacturer’s recommendation.
Check flange for cracks.
Check Marman and half Marman connections (turbine
outlet to exhaust system) for fretting damage. Where
turbine housing damage is visible refer to
Turbine and Compressor Housings for disassembly
and reassembly instructions.

Warning
KG

Turbochargers and installation parts are heavy.

Always use safe lifting methods.

4:4
HE851 Service Manual Component Testing and Replacement

Visual Checks
Check for cracked, bent or damaged compressor wheel
blades.
KG

Warning
Titanium compressor wheel edges are sharp.
Handle with care.

Where practical, check for cracked, bent or damaged

turbine wheel blades.

Caution
Never attempt to straighten blades.
KG

With intake system disconnected from compressor

housing, it may be possible to check visually for excess
bearing axial and radial clearances.
If in doubt, turbocharger must be removed from engine
to check bearing clearance against recommended
KG

values shown in Service Data Sheet.

Warning
Turbochargers and installation parts are heavy.
Always use safe lifting methods.

Caution
Air, oil and coolant hoses are specified by engine
manufacturers to perform critical functions at pressure
and temperature. To avoid leakage and potential
turbocharger and engine failures, always use
recommended components.

4:5
HE851 Service Manual Component Testing and Replacement

Bearing Clearance
Secure turbine housing and check axial clearance using
a dial gauge.
Ensure clearance is within MIN/MAX values shown on
Service Data Sheet.
If axial clearance does not meet specification replace
KG

CHRA (core) (2).

Warning
Turbochargers and installation parts are heavy.
Always use safe lifting methods.

Warning
Titanium compressor wheel edges are sharp.
Handle with care.

Check radial movement at compressor impeller nose

using a dial gauge.
KG

Ensure movement is within MIN/MAX TIR (Total

Indicator Reading) values shown on
Service Data Sheet.
If axial clearance does not meet specification replace
CHRA (core) (2).

4:6
HE851 Service Manual Component Testing and Replacement

Turbine and Compressor Housings

Turbine Housing
Place turbine outlet on a clean flat surface. Mark
turbine housing andbearing housing. This action assists
in re-assembly process defining correct component
orientation.
KG

Warning
Always wear safety glasses.

Warning
Turbine housings and CHRA assemblies are heavy.
Always use safe lifting methods.
M8 x 1.25 (13 mm A/F)
Secure turbine housing flange in vice. Use hammer and
chisel to knock lockplate tabs away from turbine
housing bolts. Loosen remove and discard 8 bolts (57)
and 4 lockplates, (50).
KG

Caution
Take care not to shear clamp plate bolts.

Seized bolts may be freed by spraying with penetrating

oil and soaking for twenty minutes or period of time
recommended by oil manufacturer.

Check bearing housing assembly rotates freely in

turbine housing. If not, gently tap turbine housing with
soft hammer. When assembly comes loose, safely lift
out of turbine housing engagement.
KG

Caution
Never direct hammer blows on to turbine housing
flange.

Caution
Turbine blades can be damaged when turbine
housing is removed.

4:7
HE851 Service Manual Component Testing and Replacement

Warning
Turbine housings and CHRA assemblies are heavy.
Always use safe lifting methods. KG

Caution
Where a crack will cause leakage to atmosphere
turbine housing must be replaced.

Cracking of internal wall at the entry to turbine wheel

(tongue) is acceptable service condition and turbine
housing may be re-used.
Always clean turbine housing before re-assembly
paying particular attention to surfaces close to turbine
wheel and bearing housing location. Refer to
Cleaning of Housings for details.

KG

Caution
Turbine housings can exhibit cracking when subject to
excessive thermal and mechanical loads.

Cracking of turbine housing inlet flange and inlet duct

generally requires turbine housing (5) replacement.
Acceptance and rejection guidelines are shown in these
illustrations. If exhaust gasket is available, always
ensure that any cracks lie within its sealing area.
Check turbine housing inlet flange flatness is within
0.1 mm (0.004 in) before retaining component for re-
use.

Flange Fasteners - Clearance Holes

KG

Check fastener hole diameter is not more than 1.5 mm

larger than max. thread diameter of the fastener.

Warning
Always wear safety glasses.

To replace turbine housing secure housing in a vice.

Apply anti seize compound to bearing housing bore
location of turbine housing.
Safely slide bearing and compressor housing assembly
into turbine housing. Use ink alignment mark to locate
housing assembly in correct orientation with turbine
KG

housing.

Caution
Turbine blades can be easily damaged when
installing in turbine housing.

4:8
HE851 Service Manual Component Testing and Replacement

M8 x 1.25 (13 mm A/F)

Warning KG
Always wear safety glasses.

Install the four new lockplates (50)* and torque tighten

eight new bolts, turbine housing (57)* to value specified
in Service Data Sheet.
Depending on housing orientation, some lockplate bolts
may have restricted access. In these cases, use
suitable torque wrench adapter attached to specially
calibrated torque wrench.

Following torque tightening it may be necessary to turn

lockplate bolts in tightening direction until flat aligns
with lock tab. Use hammer and drift to knock lockplate
tabs into position against turbine housing bolts.
KG

Warning
Titanium compressor wheel edges are sharp.
Handle with care.

4:9
HE851 Service Manual Component Testing and Replacement

Compressor Housing
Place compressor inlet on a clean flat surface. Mark
compressor housing, bearing housing and V-band
clamp to record correct orientation. This action assists
in housing orientation during re-assembly.
KG

Warning
CHRA assemblies are heavy. Always use safe lifting
methods.

M8 (6 mm A/F Allen key)

Warning
KG

Always wear safety glasses.

Secure turbine housing in vice.

Loosen and remove compressor housing V-band
locknut (62) spacer (164), and screw (96).

Warning
Titanium compressor wheel edges are sharp.
Handle with care.

Use a soft hammer to gently tap compressor housing

KG

off bearing housing.

Remove V-band clamp and retain.

Caution
Compressor blades can be damaged when
compressor housing is removed.

On some models, for example gas applications,

removal of compressor housing will expose o-ring seal
fitted into groove in diffuser flange.

Warning
If there is any possibility that seal has been
subject to fire, always wear neoprene gloves when
handling.

4:10
HE851 Service Manual Component Testing and Replacement

Warning
Titanium compressor wheel edges are sharp.
Handle with care.

Caution
Where a seal has been removed, always locate new
o-ring seal into groove in diffuser flange at this stage.
Insert new o-ring seal (41)*.

Inspect internal profile of compressor housing for

scoring damage due to possible contact with
compressor wheel. Move to Cleaning of Housings
if deposits remain.
Replace with new if profile damage is visible.
To clean compressor housings fitted with inlet baffle
move to Inlet Baffle Option.

4:11
HE851 Service Manual Component Testing and Replacement

Inlet Baffle Option

To clean compressor housings fitted with inlet baffle it is
necessary to remove baffle.

Warning
Always wear safety glasses.

Using flat screw driver, carefully apply force in area

shown (C) as retaining ring starts to move, force C D
screwdriver under ring as shown in (D).

Caution
When removing inlet baffle retaining ring, be
careful not to damage compressor wheel with
screw driver. Use rag or rubber bung to protect wheel.

Push screwdriver in anti-clockwise (counter-clockwise)

direction to force retaining ring out of groove. Remove
retaining ring.
Remove inlet baffle.

Warning
Use free hand to contain disassembled ring within
compressor inlet.

Following cleaning of compressor housing, locate inlet

baffle (34) onto location edge of compressor housing
inlet.

4:12
HE851 Service Manual Component Testing and Replacement

Warning
Always wear safety glasses and take care not to pinch
fingers during assembly.

Hold one end of retaining ring (22) in position in its

compressor cover groove. Press remainder of retaining
ring into position using free hand.
Use flat screw driver to make sure retaining ring is
correctly seated in compressor cover groove.

Warning
Turbine housings and CHRA assemblies are heavy.
Always use safe lifting methods.

Warning
Titanium compressor wheel edges are sharp. KG
Handle with care.

Ensure o ring seal is located in diffuser flange groove

where o ring was removed on disassembly. Loosely fit
V-band clamp (29)*. Carefully locate compressor
housing over compressor wheel.

Caution
Do not damage compressor blades during installation.

M8 (6 mm A/F Allen key)

Place V-band clamp in position. Insert cap head screw
(96)* and spacer (164)*. Torque tighten new locknut
(62)* to value specified in Service Data Sheet.

Caution
All HE851 models use special V-band assembly.
Always ensure that correct V-band assembly is used
and torque tightened to value specified in
Service Data Sheet.

Ensure rotor assembly freely rotates.

Warning
KG

Turbochargers and installation parts are heavy.

Always use safe lifting methods.

4:13
HE851 Service Manual Component Testing and Replacement

Cleaning of Housings

Warning
Turbine housings are heavy. Always use safe lifting
methods. KG

Visually inspect parts to detect signs of burning and

other conditions in order to obtain as much information
as possible before washing.

Caution
Housing surfaces adjacent to turbine and compressor
wheels must be clean, smooth and free from deposits.

Warning
Always wear safety glasses.

Soak housings in non-corrosive low flash point metal

KG

cleaner to loosen deposits.

Dry components using compressed air.

KG

Scale like deposits, if any, must be removed by using

non metallic bristle brush. After removing deposits , re-
wash and dry components.

KG

4:14
HE851 Service Manual Component Testing and Replacement

Warning
Turbine housings are heavy. Always use safe lifting
methods. KG

It is permissible to bead blast turbine and cast iron

compressor housings if chemical and brush cleaning is
not effective.

Warning
Always wear safety glasses.

Warning
Do not bead blast Aluminium and Cast Iron
components together.

Caution
Prevent bead spray impinging directly on clamp
plate and turbine flange threads by masking or
plugging
After removing deposits, re-wash and dry components.

4:15
HE851 Service Manual Component Testing and Replacement

Speed Sensor
Sensor Check
Disconnect the sensor at its electrical connector. Using
2 3 1

a multi-meter, check the resistance between pins 1 and

2 is in range 722 to 978 Ohm with the sensor at 20°C.
Pins 1 and 2 can be identified by reference to pin 4
location where no pin is fittted. Where resistance is
outside range, replace speed sensor (112)*

Sensor Removal
Where road spray, dirt and fluid ingress has caused
fouling or corrosion of the speed sensor apply a
penetrating oil in accordance with the oil manufacturer’s
instructions.

Warning
Always wear safety glasses.

M10 x 1 (13 mm A/F)

Using Sensor Socket, loosen speed sensor.

Caution
Breaking sealed joint may require significant torque. It
is essential that sensor socket is properly engaged on
sensor to avoid inadvertent damage to cable and
connector.

Extract speed sensor and place on clean surface to

avoid collection of metal particles.

4:16
HE851 Service Manual Component Testing and Replacement

Caution
Removal of speed sensor leaves open access to
bearing housing. It is essential that no dirt or fluids
enter bearing housing cavity during speed sensor
replacement.

Insert clean rubber plug.

Sensor Replacement

Warning
Always wear safety glasses.

Remove clean rubber plug.

Prior to inserting speed sensor (112)* ensure it is clean

and unable to collect metal particles as it is inserted.
Sensor is designed to seal directly in bearing housing
without any supplementary sealing. Do not fit an o ring
or washer.

M10 x 1.0 (13 mm A/F)

Torque tighten sensor to value specified in
Service Data Sheet.

Caution
Always use special socket wrench to prevent
damage to sensor cable.

Caution
Accurate torque wrench selection and calibration is
critical to ensure leak-proof compression joint
between sensor and bearing housing.

4:17
HE851 Service Manual Component Testing and Replacement

Safe Lifting Methods

The designated turbochargers weigh up to 60 kg (132 lb) and include sensors, electrical wiring and
connectors which are sensitive to handling.
Always use a mechanical lifting method and seek assistance.

Mechanical Handling

Warning
HE851 turbochargers are not fitted with lifting eye.
KG

Always seek assistance when lifting.

Always support the weight of turbocharger during

removal and refitting using a sling and mechanical hoist
system of correct load rating.

Warning
Never attempt to lift turbocharger manually.

4:18
Holset HE851
Service Repair Manual

Cummins Turbo Technologies Ltd.

Aftermarket Division
Croset Avenue
Huddersfield
West Yorkshire
HD1 6SE
www.holsetaftermarket.com

Copyright 2007, Cummins Turbo Technologies Ltd. All rights reserved.

VGT, Command Valve and Super MWE are trade marks of Cummins Turbo Technologies Ltd.
Holset and the Holset Logo are registered trade marks of Cummins Turbo Technologies Ltd.
Cummins and the Cummins logo are registered trade marks of Cummins Inc.
Part Number: 4029604 Rev.00 Ref. JV/KD Effect Date: 02:06