MACK Mp8 Service Manual

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MACK® MP8

DIESEL ENGINE

SERVICE MANUAL

(EURO 4)

JULY 2009 (REVISED)

5-117

MACK® MP8 DIESEL ENGINE

SERVICE MANUAL (EURO 4)

JULY 2009 (REVISED — SUPERSEDES ISSUE DATED JANUARY 2009)

ENGINE 5-117

ATTENTION

The information in this manual is not all inclusive and cannot take into account all unique situations. Note that some illustrations are typical and may not reflect the exact arrangement of every component installed on a specific chassis.

The information, specifications, and illustrations in this publication are based on information that was current at the time of publication. Note that illustrations and instructions are based on information that is subject to change as new engine/chassis development continues.

No part of this publication may be reproduced, stored in a retrieval system, or be transmitted in any form by any means including (but not limited to) electronic, mechanical, photocopying, recording, or otherwise without prior written permission of Mack Trucks, Inc.

Page ii

TABLE OF CONTENTS

Page iii

TABLE OF CONTENTS

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

SAFETY INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Advisory Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Service Procedures and Tool Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

EXPLANATION OF NUMERICAL CODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

CONVERSION CHART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

ABOUT THE MACK MP8 EURO 4 ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Service Precautions Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

VISUAL IDENTIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

MP8 EURO 4 ENGINE MODEL IDENTIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Engine Information Plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Engine Serial Number Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

DESCRIPTION AND OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

MACK MP8 EURO 4 ENGINE DESIGN FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Engine Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Lubrication System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Crankcase Ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Fuel System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

PowerLeash™ Engine Brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Exhaust Gas Recirculation System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Air Intake System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Variable Geometry Turbocharger (VGT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Engine Management System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

GLOSSARY OF TERMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

COMPONENT LOCATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

MP8 EURO 4 ENGINE COMPONENT LOCATION VIEWS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

ENGINE SYMPTOM DIAGNOSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Troubleshooting Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50

Noise and Vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

ENGINE CHECKS AND TESTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Camshaft Sensor Depth, Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Camshaft Timing, Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Crankcase Ventilation, Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56

Cylinder Head, Pressure Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57

Cylinder Liner and Piston Wear, Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

EGR Cooler, Pressure Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

Engine Compression, Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Flywheel Housing Runout, Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Oil Cooler, Pressure Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Rocker Arm, Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Thermostat, Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Valve Guide Wear, Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

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TABLE OF CONTENTS

MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

LUBRICATION SYSTEM MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Special Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Oil Level Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Oil and Filter Change Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71

Crankcase Ventilation System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71

FUEL FILTER REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Fuel Filter Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

COOLING SYSTEM MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Special Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Coolant Drain Outlets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Coolant Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

DRIVE BELT REPLACEMENT AND TENSIONING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Automatically Tensioned System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

REPAIR INSTRUCTIONS, PART 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

ENGINE REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

General Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

ENGINE DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

General Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

Mounting the Engine on a Repair Stand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

EGR Crossover Piping Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

EGR Venturi Tube Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88

Cylinder Head (Valve) Cover Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

Engine Wiring Harness Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

Timing Gear Cover Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90

Camshaft Gear and Vibration Damper Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

Rocker Arm Shaft Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92

Valve Yoke (Bridge) Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .94

Camshaft Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

Unit Injector Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

Starter Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

Turbocharger Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

EGR Hot Pipe (Cooler Inlet) Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

EGR Valve Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

EGR Cooler Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

Exhaust Manifold Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

Oil Filter Housing Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

Coolant and Pump Inlet Housings Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

Cooling Duct Cover and Oil Cooler Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

Drive Belts and Fan Hub Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

EGR Mixer Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Crankcase Ventilation (CCV) Separator Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Fuel Lines and Filter Housing Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

EECU and Cooling Plate Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

Inlet Manifold Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

Tandem Pump (Fuel and Power Steering) Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

Air Compressor Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

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TABLE OF CONTENTS

Flywheel and Pilot Bearing Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

Power Take-Off (PTO) Assembly Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

Flywheel Housing Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

Crankshaft Rear Seal Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

Timing Gear Train Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

Timing Gear Plate Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

Alternator and Refrigerant Compressor Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

Thermostat and Cover Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

Coolant Pump Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

Cylinder Head Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

Crankshaft Vibration Damper and Fan Pulley Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

Crankshaft Front Cover Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

Crankshaft Front Seal Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

Oil Fill Pipe and Dipstick Retainer Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

Oil Pan Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

Front Engine Support Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

Block Stiffener Plate Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

Oil Pump Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

Piston and Connecting Rod Assembly Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Main Bearing Cap Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

Crankshaft Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

CYLINDER BLOCK RECONDITIONING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

Tools and Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

Piston Cooling Spray Nozzle Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

Cylinder Liner Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

Block Cleaning and Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132

Liner Height Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

Cylinder Liner Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

FLYWHEEL BENCH PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

Flywheel Ring Gear Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

CONNECTING ROD AND PISTON BENCH PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

Connecting Rod — Piston Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

Piston Inspection and Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

Piston Ring Inspection and Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

Connecting Rod — Piston Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

CYLINDER HEAD OVERHAUL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

Tools and Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

Inlet and Exhaust Valve Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

Cylinder Head Cleaning and Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

Valve Guide Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

Valve Spring Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

Injector Sleeve Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

Expansion Plug Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

Valve Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156

Valve Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156

ROCKER ARM SHAFT BENCH PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

Rocker Arm Shaft Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158

Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158

Rocker Arm Shaft Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158

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CAMSHAFT BENCH PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

Camshaft Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

COOLING SYSTEM COMPONENTS BENCH PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . .161

Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161

Oil Cooler Reconditioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

EGR Cooler Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

EGR Cooler Pressure Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164

ENGINE REASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

General Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171

Crankshaft Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171

Main Bearing Cap Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

Piston and Connecting Rod Assembly Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

Oil Pump and Block Stiffener Plate Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .177

Oil Pump Pipes and Strainer Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

Front Engine Support Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

Crankshaft Front Cover and Seal Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

Timing Gear Plate Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181

Cylinder Head Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182

Camshaft Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185

Timing Gear Train Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186

Unit Injector Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

Valve Yoke (Bridge) Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

Rocker Arm Shaft and Engine Brake Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

Flywheel Housing Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196

Crankshaft Rear Seal Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198

Flywheel and Pilot Bearing Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198

Oil Pan Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200

Oil Filler Pipe and Dipstick Pipe Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202

Power Take-Off Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203

Timing Gear Cover Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203

Coolant Pump Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206

Thermostat and Cover Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206

Coolant Pipe Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207

Oil Cooler and Cooling Duct Cover Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208

Oil Filter Housing Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209

Exhaust Manifold Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210

EGR Valve Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212

EGR Cooler Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214

EGR Hot Pipe (Cooler Inlet) Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216

Turbocharger Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217

Starter Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219

Air Compressor Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220

Tandem Pump (Fuel and Power Steering) Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221

Inlet Manifold Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221

EGR Mixer Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222

EECU and Cooler Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

Fuel Lines and Filter Housing Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

Crankcase Ventilation Separator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225

Crankshaft Vibration Damper and Fan Pulley Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . .225

Alternator and Refrigerant Compressor Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226

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Wiring Harness Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227

Cylinder Head (Valve) Cover Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228

EGR Venturi Tube and Crossover Piping Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229

Fan Hub and Drive Belt Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232

Removing Engine from Engine Stand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233

Filters and Miscellaneous Components Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234

ENGINE INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235

Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235

General Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236

REPAIR INSTRUCTIONS, PART 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239

IN-CHASSIS PART/COMPONENT PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240

CAMSHAFT BEARING BRACKETS, REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240

Preliminary Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240

General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240

Camshaft Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241

Bracket Replacement Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241

Final Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242

OIL THERMOSTAT AND PRESSURE SAFETY VALVE REPLACEMENT . . . . . . . . . . . . . . . . . 243

Pressure Safety Valve Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243

Oil Thermostat Valve Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244

CRANKSHAFT FRONT SEAL REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245

Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245

Seal Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245

Seal Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246

CRANKSHAFT REAR SEAL REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248

Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248

Neoprene Seal Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248

Neoprene Seal Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248

Teflon

CRANKCASE VENTILATION (CCV) SEPARATOR REPLACEMENT . . . . . . . . . . . . . . . . . . . . . 252

CCV Separator Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252

CCV Separator Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252

OIL PUMP REPLACEMENT (IN CHASSIS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253

Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253

Oil Pump Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254

Oil Pump Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254

INJECTOR COPPER SLEEVE REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256

Tools and Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256

Preliminary Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258

Copper Sleeve Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258

Copper Sleeve Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262

Final Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265

TURBOCHARGER SMART REMOTE ACTUATOR (SRA) REPLACEMENT . . . . . . . . . . . . . . . . 266

Preliminary Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266

Turbocharger SRA Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266

Turbocharger SRA Inspection and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268

Final Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271

Seal Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249

Seal Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250

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UNIT INJECTOR CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272

Preliminary Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272

Cleaning and Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272

Final Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273

VALVE STEM HEIGHT MEASUREMENT PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274

VALVE STEM SEAL REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277

Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277

Preliminary Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278

Seal Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278

Seal Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278

Final Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279

REPAIR INSTRUCTIONS, PART 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281

MP8 ENGINE SETUP AND ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282

Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282

Valve and Unit Injector Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284

Checking and Adjusting Timing Gear Backlash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289

ENGINE FINAL PREPARATION AND OPERATIONAL CHECK . . . . . . . . . . . . . . . . . . . . . . . . . 293

Filter Element Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293

Engine Lubrication System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293

Turbocharger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293

Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294

Fuel System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294

Engine Operational Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296

REBUILT ENGINE RUN-IN PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297

Run-In Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297

SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299

MP8 ENGINE MECHANICAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300

Material and Dimensional Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300

Engine Component Torque Specifications (Critical Fasteners) . . . . . . . . . . . . . . . . . . . . . . . . 305

Standard Bolt and Nut Torque Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332

ENGINE GASKETS, LUBRICANTS AND SEALANTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333

Gasket and Seal Reuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333

Lubricants and Sealants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334

SPECIAL TOOLS & EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335

MP8 ENGINE SERVICE TOOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336

Special Tools for Engine Overhaul . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336

INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351

Page ix

NOTES

Page x

INTRODUCTION

Page 1

INTRODUCTION

SAFETY INFORMATION

Advisory Labels

Cautionary signal words (Danger-Warning-Caution) may appear in various locations throughout this manual. Information accented by one of these signal words must be observed to minimize the risk of personal injury to service personnel, or the possibility of improper service methods which may damage the vehicle or cause it to be unsafe. Additional Notes and Service Hints are used to emphasize areas of procedural importance and provide suggestions for ease of repair. The following definitions indicate the use of these advisory labels as they appear throughout the manual:

Danger indicates an unsafe practice that could result in death or serious personal injury. Serious personal injury is considered to be permanent injury from which full recovery is NOT expected, resulting in a change in life style.

Warning indicates an unsafe practice that could result in personal injury.

Personal injury means that the injury is of a temporary nature and that full recovery is expected.

Caution indicates an unsafe practice that could result in damage to the product.

Note indicates a procedure, practice, or condition that must be followed in order for the vehicle or component to function in the manner intended.

A helpful suggestion that will make it quicker and/or easier to perform a procedure, while possibly reducing service cost.

Page 2

INTRODUCTION

Service Procedures and Tool Usage

Anyone using a service procedure or tool not recommended in this manual must first satisfy himself thoroughly that neither his safety nor vehicle safety will be jeopardized by the service method he selects. Individuals deviating in any manner from the instructions provided assume all risks of consequential personal injury or damage to equipment involved.

Also note that particular service procedures may require the use of a special tool(s) designed for a specific purpose. These special tools must be used in the manner described, whenever specified in the instructions.

1. Before starting a vehicle, always be seated in the driver's seat, place the transmission in neutral, apply the parking brakes, and push in the clutch pedal. Failure to follow these instructions could produce unexpected vehicle movement, which can result in serious personal injury or death.

2. Before working on a vehicle, place the transmission in neutral, set the parking brakes, and block the wheels. Failure to follow these instructions could produce unexpected vehicle movement, which can result in serious personal injury or death.

Engine-driven components such as Power Take-Off (PTO) units, fans and fan belts, driveshafts and other related rotating assemblies, can be very dangerous. Do not work on or service engine-driven components unless the engine is shut down. Always keep body parts and loose clothing out of range of these powerful components to prevent serious personal injury. Be aware of PTO engagement or nonengagement status. Always disengage the PTO when not in use.

Do not work under a vehicle that is supported only by a hydraulic jack. The hydraulic jack could fail suddenly and unexpectedly, resulting in severe personal injury or death. Always use jackstands of adequate capacity to support the weight of the vehicle.

Before towing the vehicle, place the transmission in neutral and lift the rear wheels off the ground, or disconnect the driveline to avoid damage to the transmission during towing.

REMEMBER,

SAFETY . . . IS NO ACCIDENT!

Page 3

INTRODUCTION

Mack Trucks, Inc. cannot anticipate every possible occurrence that may involve a potential hazard. Accidents can be avoided by recognizing potentially hazardous situations and taking necessary precautions. Performing service procedures correctly is critical to technician safety and safe, reliable vehicle operation.

The following list of general shop safety practices can help technicians avoid potentially hazardous situations and reduce the risk of personal injury. DO NOT perform any services, maintenance procedures or lubrications until this manual has been read and understood.

앫 Perform all service work on a flat, level

surface. Block wheels to prevent vehicle from rolling.

앫 DO NOT wear loose-fitting or torn clothing.

Remove any jewelry before servicing vehicle.

앫 ALWAYS wear safety glasses and protective

shoes. Avoid injury by being aware of sharp corners and jagged edges.

앫 Use hoists or jacks to lift or move heavy

objects.

앫 NEVER run engine indoors unless exhaust

fumes are adequately vented to the outside.

앫 Be aware of hot surfaces. Allow engine to

cool sufficiently before performing any service or tests in the vicinity of the engine.

앫 Keep work area clean and orderly. Clean up

any spilled oil, grease, fuel, hydraulic fluid, etc.

앫 Only use tools that are in good condition,

and always use accurately calibrated torque wrenches to tighten all fasteners to specified torques. In instances where procedures require the use of special tools which are designed for a specific purpose, use only in the manner described in the instructions.

앫 Do not store natural gas powered vehicles

indoors for an extended period of time (overnight) without first removing the fuel.

앫 Never smoke around a natural gas powered

vehicle.

Page 4

INTRODUCTION

EXPLANATION OF NUMERICAL CODE

The organization of MACK service manuals has been upgraded to standardize manual content according to a reference system based on component identification. The new reference system will help link the information contained in this publication with related information included in other MACK service/warranty publications, such as associated service bulletins, warranty manuals, and MACK Service Labor Time Standards.

The system is based on a numerical code first digit of which identifies the general component grouping as listed here:

GROUP 000 — GENERAL DATA

GROUP 100 — CHASSIS

GROUP 200 — ENGINE

GROUP 300 — CLUTCH, TRANSMISSION, TRANSFER CASE AND PTO

, the

GROUP 400 — STEERING, AXLES, WHEELS AND TIRES, DRIVELINE

GROUP 500 — BRAKES, AUXILIARY SYSTEMS

GROUP 600 — CAB, TRUCK BODY

GROUP 700 — ELECTRICAL

The second two digits of the three-digit code are used to identify the system, assembly or subassembly, as appropriate, within each of the groupings. The codes applicable to this publication are shown at the beginning of each procedure, as necessary, to guide you to specific component information.

Additionally, a two-character alpha code [NV] RINGS, PISTON) may be referenced with each procedure. This alpha code, in combination with the three-digit Group number, identifies the specific assembly, sub-assembly or part, and directly relates to the first five positions of the operation code listed in MACK Service Labor Time Standards.

(i.e.,

Example:

Numerical Code

Page 5

INTRODUCTION

CONVERSION CHART

Conversion Units Multiply By:

Length Calculations

Inches (in) to Millimeters (mm) 25.40

Inches (in) to Centimeters (cm) 2.540

Feet (ft) to Centimeters (cm) 30.48

Feet (ft) to Meters (m) 0.3048

Yards (yd) to Centimeters (cm) 91.44

Yards (yd) to Meters (m) 0.9144

Miles to Kilometers (km) 1.609

Millimeters (mm) to Inches (in) 0.03937

Centimeters (cm) to Inches (in) 0.3937

Centimeters (cm) to Feet (ft) 0.0328

Centimeters (cm) to Yards (yd) 0.0109

Meters (m) to Feet (ft) 3.281

Meters (m) to Yards (yd) 1.094

Kilometers (km) to Miles 0.6214

Area Calculations

Square Inches (sq-in) to Square Millimeters (sq-mm) 645.2

Square Inches (sq-in) to Square Centimeters (sq-cm) 6.452

Square Feet (sq-ft) to Square Centimeters (sq-cm) 929.0

Square Feet (sq-ft) to Square Meters (sq-m) 0.0929

Square Yards (sq-yd) to Square Meters (sq-m) 0.8361

Square Miles (sq-miles) to Square Kilometers (sq-km) 2.590

Square Millimeters (sq-mm) to Square Inches (sq-in) 0.00155

Square Centimeters (sq-cm) to Square Inches (sq-in) 0.155

Square Centimeters (sq-cm) to Square Feet (sq-ft) 0.001076

Square Meters (sq-m) to Square Feet (sq-ft) 10.76

Square Meters (sq-m) to Square Yards (sq-yd) 1.196

Square Kilometers (sq-km) to Square Miles (sq-miles) 0.3861

Volume Calculations

Cubic Inches (cu-in) to Cubic Centimeters (cu-cm) 16.387

Cubic Inches (cu-in) to Liters (L) 0.01639

Quarts (qt) to Liters (L) 0.9464

Gallons (gal) to Liters (L) 3.7854

Cubic Yards (cu-yd) to Cubic Meters (cu-m) 0.7646

Cubic Centimeters (cu-cm) to Cubic Inches (cu-in) 0.06102

Liters (L) to Cubic Inches (cu-in) 61.024

Liters (L) to Quarts (qt) 1.0567

Liters (L) to Gallons (gal) 0.2642

Cubic Meters (cu-m) to Cubic Yards (cu-yd) 1.308

Page 6

INTRODUCTION

Conversion Units Multiply By:

Weight Calculations

Ounces (oz) to Grams (g) 28.5714

Pounds (lb) to Kilograms (kg) 0.4536

Pounds (lb) to Short Tons (US tons) 0.0005

Pounds (lb) to Metric Tons (t) 0.00045

Short Tons (US tons) to Pounds (lb) 2000

Short Tons (US tons) to Kilograms (kg) 907.18486

Short Tons (US tons) to Metric Tons (t) 0.90718

Grams (g) to Ounces (oz) 0.035

Kilograms (kg) to Pounds (lb) 2.205

Kilograms (kg) to Short Tons (US tons) 0.001102

Kilograms (kg) to Metric Tons (t) 0.001

Metric Tons (t) to Pounds (lb) 2205

Metric Tons (t) to Short Tons (US tons) 1.1023

Metric Tons (t) to Kilograms (kg) 1000

Force Calculations

Ounces Force (ozf) to Newtons (N) 0.2780

Pounds Force (lbf) to Newtons (N) 4.448

Pounds Force (lbf) to Kilograms Force (kgf) 0.456

Kilograms Force (kgf) to Pounds Force (lbf) 2.2046

Kilograms Force (kgf) to Newtons (N) 9.807

Newtons (N) to Kilograms Force (kgf) 0.10196

Newtons (N) to Ounces Force (ozf) 3.597

Newtons (N) to Pounds Force (lbf) 0.2248

Torque Calculations

Pound Inches (lb-in) to Newton Meters (N•m) 0.11298

Pound Feet (lb-ft) to Newton Meters (N•m) 1.3558

Pound Feet (lb-ft) to Kilograms Force per Meter (kgfm) 0.13825

Newton Meters (N•m) to Pound Inches (lb-in) 8.851

Newton Meters (N•m) to Pound Feet (lb-ft) 0.7376

Newton Meters (N•m) to Kilograms Force per Meter (kgfm) 0.10197

Kilograms Force per Meter (kgfm) to Pound Feet (lb-ft) 7.233

Kilograms Force per Meter (kgfm) to Newton Meters (N•m) 9.807

Radiator Specific Heat Dissipation Calculations

British Thermal Unit per Hour (BTU/hr) to Kilowatt per Degree Celsius (kW/°C) 0.000293

Kilowatt per Degree Celsius (kW/°C) to British Thermal Unit per Hour (BTU/hr) 3414.43

Temperature Calculations

Degrees Fahrenheit (°F) to Degrees Celsius (°C) (°F − 32) x 0.556

Degrees Celsius (°C) to Degrees Fahrenheit (°F) (1.8 x °C) + 32

Page 7

INTRODUCTION

Conversion Units Multiply By:

Pressure Calculations

Atmospheres (atm) to Bars (bar) 1.01325

Atmospheres (atm) to Kilopascals (kPa) 101.325

Bars (bar) to Atmospheres (atm) 0.98692

Bars (bar) to Kilopascals (kPa) 100

Bar (bar) to Pounds per Square Inch (psi) 14.5037

Inches of Mercury (in Hg) to Kilopascals (kPa) 3.377

Inches of Water (in H2O) to Kilopascals (kPa) 0.2491

Pounds per Square Inch (psi) to Kilopascals (kPa) 6.895

Pounds per Square Inch (psi) to Bar (bar) 0.06895

Kilopascals (kPa) to Atmospheres (atm) 0.00987

Kilopascals (kPa) to Inches of Mercury (in Hg) 0.29612

Kilopascals (kPa) to Inches of Water (in H2O) 4.01445

Kilopascals (kPa) to Pounds per Square Inch (psi) 0.145

Power Calculations

Horsepower (hp) to Kilowatts (kW) 0.74627

Kilowatts (kW) to Horsepower (hp) 1.34

Fuel Performance Calculations

Miles per Gallon (mile/gal) to Kilometers per Liter (km/L) 0.4251

Kilometers per Liter (km/L) to Miles per Gallon (mile/gal) 2.352

Velocity Calculations

Miles per Hour (mile/hr) to Kilometers per Hour (km/hr) 1.609

Kilometers per Hour (km/hr) to Miles per Hour (mile/hr) 0.6214

Volume Flow Calculations

Cubic Feet per Minute (cu-ft/min) to Liters per Minute (L/min) 28.32

Liters per Minute (L/min) to Cubic Feet per Minute (cu-ft/min) 0.03531

Page 8

INTRODUCTION

ABOUT THE MACK MP8 EURO 4 ENGINE [200 EA]

Figure 1 — MACK MP8 Engine — for Conventional Chassis

The MACK MP8 is a 13 liter (800 CID) engine with electronic unit injectors, a cooled Exhaust Gas Recirculation (EGR) system and the Holset Variable Geometry Turbocharger (VGT). The PowerLeash™ engine brake is optional. The engine conforms to Euro 4 emissions requirements.

The MP8 EGR system features reduced restriction plus enhanced efficiency and reliability. Its venturi system is easy to service.

The Holset VGT features fixed vanes with a sliding nozzle ring. The nozzle position is infinitely variable between open and closed. This design reacts quickly to exhaust pressure and controls inlet pressure more precisely. Reliability is enhanced by having fewer moving parts. Its actuator and bearing housing are water cooled and engine oil lubricated for greater durability.

A wide range of the current transmission offerings, including manual, automated manual and automatic, can be teamed with the MP8.

Diagnostic help can be found in the Premium/Volvo Tech Tool. In some markets the diagnostic tool is Premium Tech Tool (PTT) and in other markets the diagnostic tool is Volvo Tech Tool (VTT). Contact your local dealer for Tech Tool availability.

The engine weighs approximately 1200 kg (2646 lb.) dry (with air compressor, without oil, coolant, starter, fan, alternator and clutch). Its design includes a one-piece cylinder head, a single overhead camshaft, three rocker arms per cylinder, unit injectors and no pushrods. PowerLeash™ engine braking, requiring a fourth rocker arm, is optional. Monosteel™ steel pistons are made in one piece.

Page 9

INTRODUCTION

Do NOT use starting fluid (ether) on engines equipped with an inlet manifold air heater element. An explosion could occur. Failure to heed this danger may result in severe personal injury or death.

Two optional fan drives are available: On/Off and electronically actuated. The electronically actuated viscous fan drive is precisely controlled by the Engine Electronic Control Unit (EECU).

The electronically actuated fan drive is not available on vehicles manufactured for Australia.

Timing gears mount on the rear of the MP8 improving the flow of cooling air around the front. Special service instructions apply to the camshaft position sensor. The mounting plate, idler and camshaft gears are marked to facilitate proper installation. The air compressor drive gear meshes with the double idler instead of the auxiliary idler as on the MP7 engine.

The MP8 uses unit injectors. The unit injector incorporates the pump, valve and injector. Its internal solenoids permit fast, precise control of fuel delivery into the cylinder. The unit injectors are encased by the valve cover and not exposed to the heat of exhaust system components.

Replacing injectors requires a specific procedure, and installation requires that the EECU be programmed to recognize replacement injectors. Cleaning injector bores requires a special tool.

An engine compression brake option on the MP8 engine assists deceleration and braking. The operation of the brake differs from earlier engine models. Working in conjunction with the exhaust cycle, the brake requires a camshaft with four cams per cylinder, two rocker arms for the exhaust valves, a bridge over the two exhaust valves, an electronic control valve and a wiring harness that includes the control valve. The exhaust valves are adjusted with shims.

Preventive maintenance is important to get the most from the MACK MP8 engine and to ensure many years of reliable, trouble-free operation. Refer to the current TS943 Maintenance and Lubrication manual for schedules and specifications.

Another feature of the MP8 is the rear engine power take-off (REPTO-ready) that is gear driven through the timing gear train. An optional PTO with drive gear, bearing and housing can be added at the factory.

The rocker arm shaft is held in place by camshaft bearing capscrews. There are special instructions for installing the camshaft bearing caps and the rocker arm shaft during service.

A stiffener plate fastens to the bottom of the cylinder block to ensure block strength and rigidity. The engine can be used with axle forward or axle back vehicles by virtue of optional oil pans. The engine fan is mounted high or low depending on vehicle configuration.

Repair instructions in this manual deal with removal, installation, disassembly, assembly, setup and adjustments of MP8 components.

There are restrictions concerning the reuse of certain fasteners. Refer to current specifications bulletins and the SPECIFICATIONS section of this manual for detailed information.

Page 10

INTRODUCTION

Service Precautions Summary

Following is a summary list of the DO and DON’T issues applying to MP8 engine service.

1. DO NOT machine the cylinder head for clean-up since this will change injector depth, thereby affecting emissions. It will also upset the ability to correctly adjust timing gear backlash.

2. DO NOT grind the injector copper sleeves.

3. Install the crankshaft main bearing caps according to marked assembly number.

4. Connecting rod caps MUST BE mated to their respective connecting rods due to the “fractured manufacturing” process used. Also, the rod caps can be installed only one way because of the difference in spacing between screw holes at each side of the cap.

5. DO NOT use the lifting eye on the flywheel housing when tilting the engine/transmission assembly to an angle greater than 15 degrees.

6. Cylinder head installation requires lowering the head onto the gasket using the alignment screws and washers at the sides of the head and block. The head must be pulled back to the mounting plate using screws inserted through the plate. Pressed bosses in the gasket keep the head from making full contact with the gasket surface and prevent damage to the elastomer sealing rings as the head slides into position.

7. Do NOT use starting fluid (ether) on engines equipped with an inlet manifold air heater element.

The use of starting fluid (ether) on engines equipped with an inlet manifold air heater element is prohibited. An explosion could occur. Failure to heed this danger may result in severe personal injury or death.

8. The MP8 engine uses a number of O-rings for sealing various fluid joints and tubes. It is essential that new O-rings of the correct material be used whenever joints are disassembled and reassembled.

Page 11

NOTES

Page 12

VISUAL IDENTIFICATION

Page 13

VISUAL IDENTIFICATION

MP8 EURO 4 ENGINE MODEL IDENTIFICATION

Engine Information Plate

The engine information plate is located on the top of the cylinder head (valve) cover. This plate includes information concerning the following items.

앫 Engine model and emissions level

앫 Torque limitation

앫 SW calibration

앫 Maximum torque

앫 Rated power and speed

앫 Engine displacement

앫 Low idle speed

앫 Exhaust brake

In addition to the information plate, there is another label on the cylinder head (valve) cover. This additional label lists the chassis number, engine serial number and respective barcodes.

Figure 2 — Engine Information Plate

Engine Serial Number Identification

In addition to the engine information plate on the cylinder head cover, the engine is also identified by the engine serial number stamped into the cylinder block. This serial number is located on the block left side at the front just below the inlet manifold.

Page 14

DESCRIPTION AND OPERATION

Page 15

DESCRIPTION AND OPERATION

MACK MP8 EURO 4 ENGINE DESIGN FEATURES

[200 EA]

Figure 3 — MACK MP8 Euro 4 Engine — Conventional

Chassis

To accommodate the low cab forward design, the EGR system and the inlet manifold are configured differently than for the conventional chassis. The EGR mixer mounts at the front of the inlet manifold on the conventional chassis, but near the rear of the manifold on the low cab forward design.

Engine Components

Main features of the cylinder head are:

앫 One-piece cast iron

앫 Integral thermostat housing

Separate chambers for exhaust and inlet at each cylinder make this a “crossflow” design. The fuel channel, drilled from front to rear, connects with grooves machined around each injector opening. A plug at the rear of the cylinder head seals this channel.

CAMSHAFT AND VALVE TRAIN

The engine has an overhead camshaft and rocker arm shaft in support of four valves per cylinder. The camshaft rides on seven journals with a bearing cap and support block (saddle) at each point. The bearing inserts (shells), bearing caps and support blocks are replaceable.

In standard configuration (with VGT exhaust brake only), there are three cams for each cylinder, including inlet, injection and exhaust. There are four cams per cylinder in the optional configuration (VGT exhaust brake plus PowerLeash™) with the addition of a “brake” cam at each cylinder.

The rocker arms are positioned on the shaft (front to back) in the order of inlet, injector, exhaust and brake, if so equipped. Both the inlet and exhaust rocker arms each drive the valve pairs via a pinless yoke (bridge). On engines equipped with PowerLeash™, the “brake” rocker arm works in combination with the exhaust rocker arm to precisely control the opening and closing of the exhaust valves for engine braking.

CYLINDER HEAD

Figure 4 — Cylinder Head with Valves and Camshaft

Page 16

Supports

DESCRIPTION AND OPERATION

Figure 5 — Valve Train (with PowerLeash™)

1. Inlet Valve Yoke (Bridge)

2. Inlet Valve Rocker Arm

3. Injector Rocker Arm

4. Exhaust Valve Rocker Arm

5. PowerLeash™ Rocker Arm

6. Exhaust Valve Yoke (Bridge)

7. Shim Retaining Screw

Exhaust valve yokes include a shim for adjustment. Replaceable valve guides and seats are made of alloyed cast iron and steel respectively. All valve guides have oil seals. Exhaust valves have double valve springs.

Rollers in the ends of the rocker arms contact the cam shaft. The contacts with the yokes have ball sockets for flexibility.

Figure 6 — Camshaft and Rocker Arms (with

1. Engine Brake Cam

2. Exhaust Cam

PowerLeash™)

3. Injector Cam

4. Inlet Cam

Timing marks on the camshaft provide for valve and injector adjustment. PowerLeash™ includes its own electronic control governed by driver's choice through a switch near the steering wheel. This control mounts on the cylinder head between the No. 3 and No. 4 cylinder rocker arms. The wiring harness includes additional wire leads for PowerLeash™.

The camshaft is induction-hardened. Timing marks for valve and injector adjustment are located on the flange forward of the No. 1 camshaft journal. These marks are for adjusting valve clearance. They do not apply to camshaft timing.

Camshaft thrust washers are integral on the No. 7 journal bearing. Smooth rotation is ensured by means of a vibration damper on the camshaft gear. Teeth on the damper interact with the camshaft position sensor for input to the EECU.

Figure 7 — MP8 Engine Timing Marks — Camshaft Front

End

Page 17

DESCRIPTION AND OPERATION

CYLINDER BLOCK

The cylinder block is made of cast iron. For increased cylinder block rigidity and noise and vibration reduction, a steel stiffener plate attaches to the bottom.

The main and piston lubricating channels are drilled longitudinally through the block. These are plugged at the front of the block. The main channel opens into a cast-in channel that supplies oil to the timing gears. The piston cooling channel is covered by the timing gear cover.

HEAD TO BLOCK ALIGNMENT

Figure 9 — Head to Block Alignment Screws and

Washers

Figure 8 — Cylinder Block and Stiffener Plate

1. Cylinder Block 2. Block Stiffener Plate

Main bearing caps are made of nodular cast iron machined together with the cylinder block. Cast alignment slots in the block and tabs on the caps ensure proper alignment at installation. Each cap is marked with its location beginning with No. 1 at the front. Cap Nos. 4 and 7 are unique and are not numbered.

The block includes cylinder liners that contact the coolant directly (wet liners). The casting shape follows the contours of the cylinders to increase rigidity and reduce noise.

1. Cylinder Head

2. Alignment Screws and Washers

3. Cylinder Block

Three screws and washers installed at the side (two in the block and one in the head) align the head from side to side at assembly. Fore and aft, the head is aligned by contact with the timing gear mounting plate.

The head is aligned with the timing gear plate by screws passed through the plate into the head and tightened securely. It is extremely important to remove these screws before attempting to remove the cylinder head from the block. Failure to heed this caution may result in severe damage to the timing gear plate and other engine components.

Page 18

DESCRIPTION AND OPERATION

CYLINDER HEAD GASKET

The cylinder head gasket is made of one piece of sheet steel with vulcanized elastomer seals on oil and coolant conduits. The design of the engine and head gasket requires a unique procedure for installation of the cylinder head.

The screws and washers at the side guide the head into side-to-side alignment as it is laid on the gasket and block. Screws passed through the timing gear mounting plate into the head pull the head into alignment fore and aft. Small, stamped bosses on the gasket hold the head clear of the seals and allow it to glide accurately into position against the mounting plate during installation. Tightening the head bolts flattens the bosses on the gasket. For this reason, a new head gasket must be installed whenever the head is removed.

CYLINDER LINERS

The cylinder block uses replaceable wet cylinder liners. The lower end of each liner is sealed against the block with three elastomer rings. The upper end is sealed with a ring of EPDM elastomer situated directly under the liner collar. This design cools the upper section of the liner better because the area of coolant circulation is larger.

The lower seals are fitted in grooves in the cylinder block. The bottom seal is of a different material and fluorescent violet in color to distinguish it from the intermediate seals.

Figure 10 — Cylinder Head Gasket

Figure 11 — Cylinder Liner and Seals

1. Upper O-Ring — EPDM (Black)

2. Middle Sealing Rings — EPDM (Black)

3. Lower Sealing Ring — Viton (Purple)

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DESCRIPTION AND OPERATION

OIL PAN

The oil pan is plastic or steel with a threaded plug for draining. The plastic pan has a groove in the mounting flange which accepts a molded elastomer gasket for a seal. The steel pan is sealed with a gasket on the oil pan flange. Twenty-two spring-loaded screws clamp the pan to the block.

The oil pan includes an oil level/temperature sensor with connector. The filler tube and dipstick mounting ports are also components of the oil pan.

Oil pans with the sump at the front or at the rear are available to accommodate axle forward or axle back chassis.

CRANKSHAFT

The crankshaft is drop forged steel and induction hardened. It has seven journals with replaceable bearings. Five oversized replacement bearing options are available to accommodate crankshaft regrinding.

The rear main cap (No. 7) includes an attaching point for the lube pump. Thrust washers to control axial movement straddle the central journal (cap No. 4). The remaining caps (Nos. 1–3, 5 and 6) are numbered to facilitate correct assembly.

Figure 12 — Oil Pan and Stiffener Plate

1. Block Stiffener Plate 2. Oil Pan with Gasket

Figure 13 — Crankshaft, Bearings, Thrust Washers and Cap Alignment Tabs

1. Alignment Tab, Block

2. Alignment Tab, Cap

Page 20

3. Thrust Washers

4. Upper and Lower Bearings

DESCRIPTION AND OPERATION

A Teflon® seal bearing directly on the crankshaft flange is used at the front of the crankshaft. The front seal has an outer felt ring which serves as a dust cover. At the rear of the crankshaft is another seal that bears directly on the machined surface of the crankshaft gear. Additionally at the rear, there is a groove in the rear crankshaft flange for an O-ring which forms a seal between the flange and the gear.

PISTONS AND CONNECTING RODS

Whenever the lower main bearing caps are installed in the engine block, pay special attention to ensure the lower main bearing cap is installed in the same location of the engine block as removed. Also, ensure that the aligning mark (boss) on the bearing cap aligns with the mark (boss) on the engine block.

Figure 14 — Piston and Connecting Rod

1. Piston Ring Set

2. Wrist Pin Snap Ring

3. Piston

4. Piston Cooling Nozzle

5. Assembly Matching Marks

Connecting rods are forged steel and are used in combination with one-piece Monosteel™ steel pistons. The bearing caps are attached with four M12 capscrews spaced to prevent misalignment. The rods and caps are made by a “fracture” process that requires a cap be assembled with its original rod. Never attempt to use mismatched rods and caps.

6. Connecting Rod Bolts

7. Connecting Rod Bearing Cap

8. Upper and Lower Connecting Rod Bearings

9. Connecting Rod

10. Wrist Pin

The piston is fitted with three rings. In the top groove is a compression ring with a “keystone” cross section. In the second groove, the compression ring has a rectangular cross section. In the third groove is a spring-loaded oil scraper ring.

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DESCRIPTION AND OPERATION

Figure 15 — Piston Cooling

1. Piston Cooling Nozzle

2. Control Valve

Oil flow for the piston cooling system is controlled by two valves. The opening valve supplies oil and the control valve balances the oil flow to the piston cooling channel. The piston cooling nozzle is aligned so that the oil jet hits the underside of the piston crown.

TIMING GEARS

The timing gears are located at the rear of the engine. Backing up the gears is a plate: a 6 mm (1/4 inch) thick steel sheet attached to the cylinder block.

The advantages of this configuration are more precise timing, fewer components and lower noise levels.

3. Opening Valve

1. Crankshaft Gear

2. Double Idler Gear

3. Adjustable Idler Gear

4. Camshaft Gear and Damper

5. Auxiliary Idler Gear

Page 22

Figure 16 — Timing Gears and Plate

6. Power Steering/Fuel Pump Gear

7. Air Compressor Gear

8. Oil Pump Gear

9. Power Take-Off Gear (optional)

10. Timing Gear Plate

DESCRIPTION AND OPERATION

The power steering/fuel pump gear, the air compressor gear and the PTO gear are not timing gears. The pump and compressor gears fasten to their respective components. The pump gear is driven by the auxiliary idler gear. The compressor gear is driven by the double idler gear.

The double idler drives the adjustable idler and the gear used to drive the power take-off, if so equipped. This is part of the “REPTO-Ready” feature. A PTO unit with drive gear is substituted for a cover on the flywheel housing.

The camshaft gear fastens to the hub on the end of the shaft. A vibration damper also attaches to the hub outboard of the gear. Teeth on the damper actuate the camshaft position sensor. The gear is driven via the adjustable idler.

DRIVE BELTS

This engine can be configured to accommodate either the conventional chassis or the low cab forward (LCF, see note) design. Depending on the vehicle, the fan location may be high or low on the fan bracket.

MACK Australian manufacturing covers only conventional chassis models. The low cab forward chassis models (LEU and MRU series) referenced in this section are not manufactured in Australia.

Two poly-V belts drive the front engine accessories. The outer, primary belt (10 or 12 ribs) drives the coolant pump and fan hub from a pulley on the crankshaft flange nested in the vibration damper. The inner, secondary belt (six ribs), driven by the crankshaft vibration damper, drives the alternator and refrigerant compressor.

Figure 17 — Primary and Secondary Drive Belts —

1. EGR Cooler Outlet Pipe

2. Fan Drive

3. EGR Mixer

4. Belt Tensioner (Alternator/Refrigerant Compressor Belt)

5. Alternator (Pad Mount)

Conventional Chassis

6. Refrigerant Compressor (Pad Mount)

7. Belt Tensioner (Fan Drive/Coolant Pump Belt)

8. Coolant Pump

9. Venturi

10. Differential Pressure Sensors

Each belt uses an automatic tensioner. In the high position, Figure 17, there are two idler pulleys in the primary loop: one between the coolant pump pulley and the tension idler; the other between the crankshaft pulley and the fan hub.

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DESCRIPTION AND OPERATION

Figure 18 — Primary and Secondary Drive Belts — LCF

1. EGR Cooler Outlet Pipe

2. Fan Drive

3. EGR Mixer

4. Belt Tensioner (Alternator/Refrigerant Compressor Belt)

5. Alternator (Pad Mount)

Chassis (N/A Australia)

6. Refrigerant Compressor (Pad Mount)

7. Belt Tensioner (Fan Drive/Coolant Pump Belt)

8. Coolant Pump

9. Venturi

10. Differential Pressure Sensors

Lubrication System

A gear-type pump at the rear of the engine, driven by the crankshaft gear, draws lubricant from the oil pan and supplies the system. Oil flows from the pump through the distribution housing to the filters, to a gallery at the right side of the engine serving the crankshaft journals, to a gallery at the left side serving piston lubrication and cooling, to the cylinder head and rocker shaft duct (valve rocker and camshaft) and back to the oil pan. The system includes crankcase ventilation.

Two full-flow filters and a by-pass filter maintain clean lubricant. A sensor in the oil pan monitors fluid level. There is an oil cooler immersed in engine coolant inside the cooling duct cover.

In the low position, Figure 18, the idler between the damper and fan pulleys is omitted.

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OIL PUMP

DESCRIPTION AND OPERATION

Figure 19 — Lubrication System Diagram

A strainer and pickup tube lead the lubricant into the pump. For the axle forward oil pan, the strainer is mounted on a short tube held in place by a bracket attached to the distribution housing. For the axle back model, a long tube without the bracket is supplied.

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DESCRIPTION AND OPERATION

OIL FLOW CONTROL AND FILTRATION

Figure 20 — Lubrication System Flow Diagram

1. Strainer

2. Pickup Tube

3. Oil Pump

4. Pressure Pipe

5. Oil Cooler

6. Filter Housing

7. Full-Flow Filters

8. Main Lubrication Gallery

9. CCV Separator

10. Engine Brake Oil Control Valve

11. Air Compressor

There are three filters, one by-pass and two full-flow, attached to a housing mounted at the lower right side of the engine. Oil flow through the filters and the lubrication system is controlled by six valves, including:

앫 Reducing Valve

앫 Safety Valve

앫 Oil Cooler Thermostat Valve

앫 Overflow Valve, Full-Flow Filter

앫 Opening Valve, Piston Cooling

12. Turbocharger

13. By-Pass Filter

14. Piston Cooling Nozzles

15. EGR Valve A. Reducing Valve B. Safety Valve C. Oil Cooler Thermostat Valve D. Overflow Valve, Full-Flow Filter E. Opening Valve, Piston Cooling F. Control Valve, Piston Cooling

The reducing valve maintains constant system oil pressure. The safety valve prevents excessive pressure during periods of high viscosity. The oil cooler thermostat valve prevents oil from entering the cooler until it warms to the set point. The overflow valve allows oil to by-pass the filter if it becomes clogged. The opening valve prevents oil from moving to the piston cooling outlets until the system reaches the set pressure. The control valve regulates the oil flow to the piston cooling channels.

앫 Control Valve, Piston Cooling

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DESCRIPTION AND OPERATION

Crankcase Ventilation

Lubricant becomes a mist in many areas of the engine as the result of the motion of the parts (e.g., rocker arms, pistons, crankshaft, camshaft and rocker shaft). The mist rides the drafts of air and other gases that circulate in the open spaces in the engine. To prevent pressure buildup, the

open spaces are ducted through a pipe that opens to the atmosphere near the bottom of the engine.

The crankcase ventilation (CCV) system separates the oily mist from the gases by centrifugal force. The oil returns to the oil pan. The remainder escapes to the atmosphere.

Figure 21 — Crankcase Ventilation System Separator

1. Seal Ring

2. Separator Inlet Hose

3. Separator Vent Tube

4. Vent Tube Bracket

A turbine in the CCV separator, driven by a small stream of oil striking its fins, spins at high speed. The mixture of gases and oily mist trapped in the valve cover and the timing gear cover drains onto the top of the center of the turbine and runs down onto several discs rotating with the turbine. Separation occurs as the mixture, flung outward by the turbine, strikes the walls of the CCV. The droplets of mist coalesce into a liquid and drain back into the oil pan along with the oil that drives the turbine. The gases are free to leave via an open port.

5. Separator Housing

6. Housing Seal

7. Pressure Regulator

The open port connects to a tube leading to the bottom of the engine where road draft draws the gases into the atmosphere.

Page 27

Fuel System

DESCRIPTION AND OPERATION

Figure 22 — Fuel System Diagram

1. Fuel Pump

2. Fuel Tank and Inlet Tube

3. EECU Cooler

4. Fuel Filter Housing

5. Fuel Pre-Filter

6. Water Cup

7. Secondary (Main) Filter

8. Fuel Gallery

9. Unit Injector

10. Pressure Regulator Valve

11. Pump Safety Valve (Pressure Regulator)

12. One-Way Valve

The fuel pump attaches with the power steering pump to the flywheel housing at the rear left side. It turns on the same shaft as the power steering pump. The common drive gear meshes with the auxiliary idler driven by the crankshaft gear. At 600 rpm, the pump delivers a minimum 100 kPa (14.5 psi), and at 1200 rpm, 300 kPa (43.5 psi). At 400–550 kPa (58–80 psi), the gallery regulator valve opens to control fuel gallery pressure.

13. Hand Pump Handle

14. Water Level Sensor

15. Water Discharge Control Switch (Instrument Panel) (N/A Australia)

16. Electrical Water Drain Valve (non-electric for Australian vehicles)

17. Automatic Air Bleed Valve (closes when filter removed)

18. Service Port (Pressure Gauge)

19. Supply Pressure Sensor

20. Fuel Heater (Optional)

21. Service Shutoff Valve (closes when filter removed)

22. One-Way Valve (Hand Priming)

23. Automatic Air Bleed Valve

24. Fuel Tank Breather

Page 28

DESCRIPTION AND OPERATION

Fuel is drawn by the suction side of the fuel pump from the fuel tank into the ECU cooling plate and enters the fuel filter housing. Fuel passes by the one-way check valve which prevents the bleeding of fuel back to the fuel tank and into the primary fuel filter. The fuel becomes filtered by passing through the filter media from the outside to the center of the primary fuel filter. The fuel leaves the primary filter and passes by a one-way valve located in the threaded nipple of the primary filter. The fuel flows from the filter housing to the suction side of the fuel pump through an external fuel line. Fuel becomes pressurized after leaving the fuel pump and flows back to the filter housing to enter the secondary filter. The fuel becomes filtered by passing through the filter media from the outside to the center of the secondary filter. The fuel leaves the secondary filter and passes by an automatic air bleed valve which is located in the threaded nipple for the secondary filter. Fuel passes by the fuel pressure sensor and then exits the filter housing to enter the rear of the cylinder head through an external fuel line. After fuel enters the cylinder head, it passes through the fuel gallery of the cylinder head to continuously deliver fuel to all six unit injectors. Fuel leaves the cylinder head after passing by the fuel pressure regulator located at the left front corner of the cylinder head. Fuel is routed back from the cylinder head to the filter housing through an external fuel line to deliver some return fuel back into the suction side which goes to the fuel pump. Any excessive fuel not consumed is bled off through the de-aeration valve and then, directed back to the fuel tank.

FUEL FILTRATION

Primary and secondary filter elements attach to the underside of the fuel filter housing. The housing, located at the front lower left side of the cylinder block, has an integral hand-priming pump for bleeding the system. The 30 micron pre-filter (primary filter) also separates water from the fuel. Water collects in a cup on the bottom of the pre-filter. There is a sensor to keep track of the water and signal the EECU.

For vehicles with electrical drain valves, the collected water can be dumped only while the engine is not running, the key is in the ON position and the parking brake is set.

For vehicles manufactured in Australia, only non-electrical drain valves are available.

A one-way check valve located in the filter housing prevents fuel from draining back to the fuel tank when the engine is shut down. Also included in the valve housing is the fuel pressure sensor just above the primary filter.

Page 29

UNIT INJECTORS

DESCRIPTION AND OPERATION

Figure 23 — Unit Injector Diagram

1. Injector Yoke

2. Copper Sleeve

3. O-Ring

4. Fuel Gallery

5. O-Ring

6. O-Ring

7. Pressure Relief Valve

This engine uses double solenoid unit injectors. Unlike systems that require separate components for delivering, pressurizing and injecting, this unit injector combines these functions. These injectors precisely control the fuel delivery because of the two solenoids. The solenoids, pump and nozzle are in a single body in close proximity to each other.

The injector is set in a pressurized fuel gallery where the fuel temperature is constant. Uniform fuel temperature means uniform quantity in each injection which means uniform power output from each cylinder.

8. Solenoid Coil

9. Solenoid Coil

10. Injector Valve

11. Injector Piston

12. Injector Nozzle

13. Washer

The fuel pump pressurizes the gallery so that fuel rushes into each injector when it opens. Gallery pressure is regulated by a valve that delivers excess fuel back to the tank.

Copper sleeves, acting as coolant jackets, line the bottoms of the injector bores. Engine coolant circulates around these sleeves aiding the process of controlling injection temperature.

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DESCRIPTION AND OPERATION

There are four phases to the injector cycle of operation. These include:

앫 Fill phase

앫 Spill phase

앫 Injection phase

앫 Pressure drop phase

Figure 24 — Unit Injector — Fill and Spill Phases

1. Pump Plunger

2. Fuel Gallery

Fill phase (A): During the filling phase, the pump plunger is on its way up, the camshaft lobe is passing its highest point and the rocker arm is on its way toward the camshaft base circle. The fuel valve is open, allowing fuel to flow into the unit injector from the lower fuel gallery. Fuel flows into the cylinder head and the unit injector pump cylinder. Filling continues until the pump plunger reaches its upper position.

3. Injector Nozzle

Spill phase (B): The spill phase begins when the camshaft lobe forces the rocker arm to push the pump plunger down. The fuel can now flow through the fuel valve, through the holes in the unit injector and out through the fuel gallery. The spill phase continues as long as the fuel valve is open.

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DESCRIPTION AND OPERATION

Figure 25 — Unit Injector — Injection and Pressure Drop Phases

1. Pump Plunger

2. Fuel Gallery

Injection phase (C): The injection phase begins when the fuel valve closes. The camshaft lobe and rocker arm continue to press down on the pump plunger and injection occurs as the path through the fuel valve closes. The injection phase continues as long as the fuel valve is closed.

Pressure drop phase (D): The injection phase ends when the fuel valve opens and pressure in the unit injector drops below the nozzle opening pressure. The fuel flows through the open fuel valve, through the unit injector holes and out through the fuel gallery. Note that the fuel valve position (closed or open) determines when the injection phase begins and ends. The time during which the fuel valve is closed determines the amount of fuel injected at each pump stroke.

Unit injectors are categorized and coded with regard to tolerances. Whenever a unit injector is replaced, the replacement injector MUST be programmed for the cylinder in which it is installed. This is done by programming EECU parameters using the VCADS pro or the Premium/Volvo Tech Tool to set Injector Trim parameters with the trim codes marked on the injectors.

3. Injector Nozzle

The dimension by which the injector nozzle extends from the head is critical. This means that machining the head in any way that changes this nozzle extension is not permitted.

Page 32

Figure 26 — Injector Coding

1. Serial No. 2. Unit Calibration No.

DESCRIPTION AND OPERATION

PowerLeash™ Engine Brake

The engine can be equipped with a PowerLeash™ engine brake system to assist in slowing the vehicle when necessary. The system includes the:

앫 Wiring harness

앫 Camshaft

앫 Oil control valve

앫 Exhaust rocker arms

앫 Engine brake rocker arms

앫 Exhaust valve yokes (bridges)

The exhaust rocker arms contain a pump piston in addition to the power piston and non-return valve. An additional “brake” rocker arm, working in combination with the exhaust rocker arm, drives the pump piston for engine braking.

At each cylinder, there is a fourth cam to drive the brake rocker arm. This cam contains the charging and decompression lobes which are timed to open the exhaust valves at the end of the induction stroke and immediately before TDC on the compression stroke when engine braking is activated.

The engine brake rocker arm is equipped with a blade spring. The purpose of the blade spring is to keep the roller in contact with the fourth “brake” cam.

PowerLeash™ operation depends on all of the following conditions which must exist simultaneously.

앫 Accelerator pedal released

앫 Engine speed above 1100 rpm

앫 Clutch pedal released

앫 Road speed above 5 km/h (3.1 mph)

앫 ABS inactive

앫 Transmission in gear

Figure 27 — PowerLeash™ (4-Rocker) Components

앫 Oil temperature above 55°C (131°F)

앫 Charge air pressure below 50 kPa (7.25 psi)

On the cylinder head, the oil control valve connects the oil passages in the head and rocker shaft. The oil pump produces constant pressure at this junction. While the accelerator pedal is depressed, the control valve reduces the oil pressure in the rocker shaft to a minimum 100 kPa (14.5 psi).

1. Camshaft

2. Charging Lobe

3. Decompression Lobe

4. Exhaust Rocker Arm

5. Pump Piston

6. Power Piston

7. Non-Return Valve

8. Piston

9. Spring

10. Brake Rocker Arm

11. Exhaust Lobe

Page 33

DESCRIPTION AND OPERATION

Figure 28 — PowerLeash™ Oil Control Valve — Location

1. Tie Wraps

2. Electrical Connector

3. Attaching Screws

4. Solenoid

5. Tube — Valve to Shaft

Figure 29 — Cylinder Head Oil Pressure Access Port

System Oil Pressure

Engine

Speed/RPM Temperature Pressure

600 90–110°C

(195–230°F)

>1100 90–110°C

(195–230°F)

>1100 Cold Engine 650 kPa

>250 kPa (>36 psi)

300–550 kPa (44–80 psi)

(95 psi)

When the accelerator pedal is released (and the PowerLeash™ switch is ON), the solenoid opens allowing some oil to escape through a small port. Reduced spring pressure moves the piston, opens the passage to the rocker shaft and increases the oil pressure. The system opens the exhaust valve during induction and again immediately before TDC on the compression stroke.

The engine slows because the extra volume under compression takes more power to compress, and escaping pressure in the combustion stroke reduces the power output. A switch on the instrument panel allows the driver to engage or disengage PowerLeash™.

If the ABS system becomes active, it automatically disables PowerLeash™. If the oil temperature goes below 55°C (131°F), PowerLeash™ cannot be activated. A warning lamp on the instrument panel flashes if the driver attempts to activate it under this condition.

A port located in the front cylinder head near the thermostat allows access to the oil passageway. The plug can be removed and a gauge and hose assembly inserted for use during diagnostic procedures.

Rocker Shaft

Engine Brake

Active 900–2300 220 kPa

Inactive — 80–120 kPa

Engine

Speed/RPM Oil Pressure

(32 psi)

(12–17 psi)

Page 34

DESCRIPTION AND OPERATION

Exhaust Gas Recirculation System

Figure 30 — EGR Components — Conventional Chassis

1. EGR Valve

2. EGR Cooler Inlet Pipe

3. EGR Cooler

4. Venturi

Nitrous oxide (NOx) emission levels increase with combustion temperature. The primary function of the Exhaust Gas Recirculation (EGR) system is to cool exhaust gas and send it back to the combustion chamber to lower the combustion temperature thereby to reduce NOx emissions.

EGR systems are configured differently for the low cab forward (LCF, see note) and conventional chassis engines. The mixer, where the recirculated exhaust joins the inlet air, mounts at the front of the inlet manifold for the conventional chassis, but for the LCF chassis, it is located near the rear of the manifold. This requires differences in the ducting from the EGR cooler to the mixer.

Engine

5. Differential Pressure Sensors

6. EGR Cooler Outlet Pipe

7. EGR Mixer

EGR VALVE

This engine uses the EGR valve to recirculate exhaust gases. Engine oil operates the EGR valve. The EECU determines the desirable valve opening based on inputs from a number of sensors and commands the EGR valve solenoid to open or close the valve.

Corrosion occurs in the inlet manifold if exhaust gas condenses there. This can produce both internal and external damage. To eliminate corrosion, the EECU compares engine RPM, torque load, ambient temperature, inlet manifold temperature and EGR demand to calculate the dew point in the inlet manifold. It then adjusts the EGR opening to stay above the dew point. Additionally, surfaces within the inlet manifold and the mixing chamber are treated to resist corrosion.

The EGR valve attaches to the rear section of the exhaust manifold for reliable response and turbocharger efficiency. This location also protects the EGR cooler from harmful high pressure exhaust pulses that occur during engine braking.

EGR VALVE FUNCTION

When the EGR valve is open, exhaust gas recirculates into the combustion chamber. The valve is normally closed when engine coolant temperature is below 65°C (149°F) unless the EECU commands the valve open during automatic cooler cleaning mode. When coolant temperature exceeds 65°C (149°F), engine load exceeds 50%, and RPM exceeds 1200, the EECU opens the EGR valve to approximately 90% of its range.

At idle, the EECU monitors exhaust temperature every three minutes. If it exceeds 98°C (208°F), the valve opens to approximately 14% of its range. Otherwise, it remains closed.

MACK Australian manufacturing covers only conventional chassis models. The low cab forward chassis models (LEU and MRU series) referenced in this section are not manufactured in Australia.

Page 35

DESCRIPTION AND OPERATION

EGR COOLER INLET PIPE

Figure 31 — EGR Valve and Cooler Inlet Pipe

1. EGR Valve

2. Cooler Inlet Pipe

3. Clamps

4. EGR Cooler

5. Electrical Connector

6. Oil Supply Line

EGR COOLER OUTLET PIPE

The EGR cooler outlet pipe carries the exhaust gas from the venturi to the mixer. Relatively short, the tube passes over the valve cover, behind and into the mixer at the front end of the inlet manifold on the conventional chassis engine.

Relatively much longer on the LCF (N/A Australia), the tube passes from the venturi around the front of the valve cover and reaches back to the mixer at the rear end of the inlet manifold.

A temperature sensor monitors exhaust temperature sending the data to the EECU. Excessively high temperature, or abnormally high temperature for more than 30 minutes during an hour, causes the EECU to limit engine power to prevent engine damage.

EGR MIXER

The EGR mixer is the meeting point for cooled, recirculating exhaust gas and outside air from the CAC. From here, the combined gases pass into the inlet manifold and on to the combustion chamber.

The cooler inlet pipe (hot pipe) conducts the exhaust from the EGR valve to the EGR cooler. The cooler lowers the exhaust stream temperature before it reenters the combustion chamber.

EGR COOLER

The EGR valve is connected to the EGR cooler by the cooler inlet pipe (hot pipe). Using engine coolant, the EGR cooler lowers the temperature of the gas coming from the EGR valve. The cooler contains a series of vanes that increase cooling efficiency by swirling the hot gas before it enters the mixer.

EGR VENTURI SYSTEM

On leaving the EGR cooler, the gas flows through a venturi equipped with two pressure sensors. The venturi changes the speed and density of the flow. The sensors report the pressure difference to the EECU.

INLET AIR HEATER

The optional inlet air heater mounts between the mixer and the inlet manifold. It is activated when the operator turns the key to the preheater position and the engine coolant temperature is lower than 10°C (50°F).

Operating time is controlled by the EECU. The operating relay is mounted on the inlet manifold. A lighted icon on the instrument panel signals when the element is On.

EGR DIAGNOSTICS

The EECU commands the EGR valve position and monitors electric current consumed by the EGR valve. An abnormally high reading indicates a jammed EGR valve. The EECU verifies that its command was sent and that the valve position reflects the command. If the valve is jammed, or its position doesn't change when commanded, the EECU sets fault codes.

Page 36

DESCRIPTION AND OPERATION

A degraded EGR cooler results in low efficiency. The EECU calculates efficiency by comparing EGR gas temperature with engine coolant and exhaust temperatures. An EGR cooler clogged with soot also causes a fault code to be set.

Air Intake System

On the conventional chassis models, fresh air enters the air filter assembly through intakes and ducts integral to the hood. For the cabover and low cab forward (LCF) chassis models (N/A Australia), fresh air enters the vertical intake stack at the back of the cab. An impregnated paper filter prevents foreign particles from passing through. The assembly design permits the addition of a second filter if needed in extreme environments.

A combination pressure/temperature sensor mounted on the pipe between the filter housing and the turbocharger alerts the driver if the filters need replacement before the scheduled service. The brake system air compressor also draws fresh, clean air from this same pipe.

Variable Geometry Turbocharger (VGT)

Figure 32 — VGT and Electronic Control

The variable geometry turbocharger is also used as an exhaust brake. The engine control unit (EECU) regulates the turbocharger’s sliding nozzle ring and vanes to increase the exhaust back pressure during braking. This causes the engine to drag, producing a braking effect on the vehicle.

The engine is equipped with a variable geometry turbocharger (VGT). The turbine housing has a set of vanes and a sliding nozzle ring that maintains sufficient back pressure in the exhaust manifold for proper operation of the EGR system. A certain amount of back pressure is required to push the exhaust gases into the pressurized intake air at the EGR mixer.

Cooling System

The cooling system incorporates a belt-driven coolant pump mounted on the front of the engine on the right. It also uses a piston-type thermostat housed in the front of the cylinder head and a fan with viscous (see note) or air-operated drive mounted above the crankshaft pulley.

The electronically actuated viscous fan drive referenced in this section is not available on vehicles manufactured for Australia.

COOLANT PUMP

The back of the coolant (water) pump, with its ducts for distributing coolant, is a separate casting attached to the cylinder block.

Page 37

DESCRIPTION AND OPERATION

The coolant pump contains an impeller, shaft seals, bearing and pulley which attach to the mounting plate. The bearing is a permanently lubricated combination roller and ball bearing. Between the shaft seals and the bearing, there is a ventilated space which leads into a duct behind the pulley. This allows internal leaks to be detected.

Figure 34 — Electronically Actuated Viscous Fan Drive

Assembly (N/A Australia)

Figure 33 — Coolant (Water) System Components

1. Coolant Pump

2. Coolant Pump Seal

3. Coolant Pump Mounting Plate

THERMOSTAT

This is a piston-type, full-flow thermostat with piston, bulb, seal and housing in a single assembly. Coolant flows continuously, either back to the pump, or to the radiator and back to the pump. It has lower pressure drop compared to other types. The thermostat is mounted in the front of the cylinder head.

ENGINE COOLING FAN

The cooling fan (Figure 34) runs via a viscous (N/A Australia) or air-operated drive through which fan speed is electronically controlled by the EECU. With precise EECU control, fan speed is continuously adjusted in response to several interrelated influences. This makes for efficient cooling with low fuel consumption.

1. Solenoid Valve and Speed Sensor

2. Connector (to EECU)

Engine Management System

ENGINE ELECTRONIC CONTROL UNIT (EECU)

Figure 35 — EECU and Cooler

The engine management system module, also known as the Engine Electronic Control Unit (EECU), is located on the left side of the engine just below the inlet manifold. The EECU is cooled by fuel circulating through a plate attached to the cover of the unit. The fuel comes from the tank on its way to the fuel pump.

Page 38

DESCRIPTION AND OPERATION

Algorithms, called maps, are programmed in the EECU so that it can translate sensor data into action. These maps enable the EECU to receive status information from the sensors and send functional data to the actuators so they can simultaneously assume the proper posture for the safest, most efficient operation of the engine in any given instant.

Due to the EECU self-learning capability, it is necessary to reset the learned EECU parameters after servicing some engine-related components.

This allows the EECU to learn the new component's behavior. After servicing is complete, perform the “Learned Data Reset” located in the Function Group 1 menu on the PC tool.

SENSORS AND ACTUATORS

Sensors on the engine provide for electronic control. The figures that follow show the locations of the devices on the left and right sides of the engine, respectively.

Figure 36 — MP8 Euro 4 Engine Sensors

1. Water Level (in fuel/water separator)

2. Oil Level/Temperature

3. Fuel Pressure

4. Fan Speed (in fan hub; N/A Australia)

5. Coolant Level Sensor (in expansion tank)

6. Charge Air Pressure

7. Coolant Temperature (at front edge of cylinder head)

8. Charge Air Temperature

9. Camshaft Position

10. Inlet Humidity/Temperature

11. Engine Position/Speed

12. Oil Pressure

13. Crankcase Pressure

14. Differential Pressure (on venturi tube)

15. EGR Temperature

16. Turbocharger Speed (on VGT bearing housing)

Page 39

DESCRIPTION AND OPERATION

GLOSSARY OF TERMS

Atmospheric Pressure Sensor

A sensor incorporated into the EECU that detects atmospheric (barometric) pressure and relays this value to the EECU. This pressure is affected by altitude.

Carbon Monoxide (CO)

An odorless, colorless gas resulting from incomplete combustion of hydrocarbons; found in diesel truck exhaust; poisonous to humans and animals.

Compressor Discharge Temperature Sensor

Mounted between the turbocharger compressor housing and CAC, detects compressor discharge air temperature and relays this value to the EECU.

Cooled Exhaust Gas Recirculation (CEGR)

A system whereby a pre-determined amount of exhaust gas is diverted through a heat exchanger where it is cooled and sent to the inlet manifold for introduction into the combustion chambers. Adding the cooled exhaust gases to the combustible fuel and air mixture lowers the overall combustion temperatures for reduced formation of nitrogen oxides (NOx).

Electronic Unit Injector (EUI)

Controlled electronically by the EECU, there is one electronic unit injector for each cylinder of an engine. A unit injector incorporates the pump, the injector nozzle and two solenoids in a single body. Actuated by the camshaft via rocker arms with roller followers, electronic unit injectors offer precise fuel metering using a process called “rate shaping.”

Engine Electronic Control Unit (EECU)

A microprocessor-based controller usually mounted on the cylinder block. On the MP8 engine, a cooling plate mounts on the surface of the module. A tube on the plate conducts fuel drawn from the tank on its way to the pump before being pressurized. The fuel acts as the coolant. With the MACK V-MAC EECU controls fuel timing and delivery, exhaust gas recirculation, fan operation, engine protection functions and engine brake operation.

IV system, the

Exhaust Gas Recirculation (EGR)

A system whereby a pre-determined amount of exhaust gas is returned to the combustion chambers. Adding a small percentage of exhaust gas to the fuel/air mixture lowers the combustion temperature reducing the formation of nitrogen oxides (NOx).

Hydrocarbons (HC)

Chemical compounds composed only of carbon and hydrogen. Gasoline, diesel fuel and motor oil are all examples of a very large group of hydrocarbons. The largest source of hydrocarbons is petroleum.

Idler Gear

A gear running between a driving and a driven gear to make the driven gear rotate in the same direction as the driving gear.

Idler Tensioner

A belt tensioning device designed to maintain optimum tension under varying engine speeds and load.

Intake Air Temperature and Humidity Sensor

Mounted in the air intake between the air cleaner and the turbocharger compressor housing, detects outside air temperature and humidity and relays these values to the EECU.

Oxides of Nitrogen (NOx)

High temperatures and pressures of combustion produce oxides of nitrogen (NOx). When combustion temperature exceeds 1372°C (2,500°F), oxygen and nitrogen combine in large quantities to form NOx. By themselves, NOx emissions are no great hazard; however, when mixed with the right amount of HC in the air, NOx will combine in the presence of sunlight to form smog.

Poly-V Belt

A multi-ribbed belt design incorporated into the accessory drive belt and pulley arrangement at the front of the engine.

Page 40

DESCRIPTION AND OPERATION

Pressure Differential Sensors

These are devices designed to read air (gas) pressure at two points in the path of the flow and report the values for use in algorithms in the EECU.

Roller Follower

A type of rocker arm with an axle-mounted roller that rides on (or follows) a camshaft lobe. The rolling motion of this design provides increased load capacity with less friction than the flat-faced rocker arm design. Roller followers provide the rocker arm lifting action for the electronic unit injector, intake and exhaust valves and exhaust brake.

Variable Geometry Turbocharger (VGT)

The turbocharger turbine housing has moving components to control flow of exhaust gas and build back pressure in the exhaust system for EGR flow. The VGT also performs as an engine brake.

VGT Wheel Speed

A sensor mounted in the turbocharger bearing housing that detects turbine and compressor wheel speed and relays this data to the EECU.

Vehicle Electronic Control Unit (VECU)

A microprocessor-based controller, sometimes referred to as a module, mounted in the cab, inside the passenger-side dash panel. With the MACK V-MAC IV system, the VECU controls engine speed, cruise control, accessory relay controls, idle shutdown and trip recorder functions.

Page 41

NOTES

Page 42

COMPONENT LOCATOR

Page 43

COMPONENT LOCATOR

MP8 EURO 4 ENGINE COMPONENT LOCATION VIEWS

[200 EA]

The locations of primary component assemblies of the MP8 engine are identified in the illustrations contained in this section.

Figure 37 — MACK MP8 Euro 4 Engine, Right-Side View (Front >), Conventional Chassis

1. EGR Valve

2. Variable Geometry Turbocharger

3. EGR Mixer

4. EGR Cooler Outlet Pipe

5. Thermostat

6. Differential Pressure Sensors

7. Venturi

For Australia, engines are not equipped with the coolant filter shown in Figure 37. VCS coolant is used to protect the cooling system.

Page 44

8. Coolant Filter (N/A Australia)

9. Full Flow Oil Filters

10. Bypass Oil Filter

11. Starter

12. EGR Cooler

13. EGR Cooler Inlet Pipe

COMPONENT LOCATOR

Figure 38 — MACK MP8 Euro 4 Engine, Left-Side View (< Front), Conventional Chassis

1. EGR Mixer

2. EGR Cooler Outlet Pipe

3. Air Compressor

4. Power Steering Pump

5. Low Pressure Fuel Pump

For the conventional chassis, the air inlet is at the front of the inlet manifold which is the configuration shown in Figure 38. For the low cab forward (LCF) and cabover chassis, the air inlet is located near the rear of the manifold.

MACK Australian manufacturing covers only conventional chassis models. The low cab forward chassis models (LEU and MRU series) referenced in this section are not manufactured in Australia.

6. Fuel Filters

7. Refrigerant Compressor (Pad Mount)

8. Alternator (Pad Mount)

9. CCV Separator

Page 45

COMPONENT LOCATOR

Figure 39 — MACK MP8 Euro 4 Engine, Left-Side View (< Front), LCF Chassis (N/A Australia)

1. EGR Cooler Outlet Pipe

2. EGR Mixer

3. Air Compressor

4. Power Steering Pump

5. Low Pressure Fuel Pump

6. Fuel Filters

7. Refrigerant Compressor (Pad Mount)

8. Alternator (Pad Mount)

9. CCV Separator

Page 46

COMPONENT LOCATOR

Figure 40 — MACK MP8 Engine, Front View,

Conventional Chassis

Figure 41 — MACK MP8 Engine, Front View, LCF

Chassis (N/A Australia)

1. EGR Cooler Outlet Pipe

2. Fan Drive

3. EGR Mixer

4. Belt Tensioner (Alternator/Refrigerant Compressor Belt)

5. Alternator (Pad Mount)

6. Refrigerant Compressor (Pad Mount)

7. Belt Tensioner (Fan Drive/Water Pump Belt)

8. Water Pump

9. Venturi

10. Differential Pressure Sensors

1. EGR Cooler Outlet Pipe

2. Fan Drive

3. EGR Mixer

4. Belt Tensioner (Alternator/Refrigerant Compressor Belt)

5. Alternator (Pad Mount)

6. Refrigerant Compressor (Pad Mount)

7. Belt Tensioner (Fan Drive/Water Pump Belt)

8. Water Pump

9. Venturi

10. Differential Pressure Sensors

Page 47

NOTES

Page 48

TROUBLESHOOTING

Page 49

TROUBLESHOOTING

ENGINE SYMPTOM DIAGNOSIS [200 EA]

The Vehicle Management and Control (V-MAC IV) system monitors engine function and displays a code when a fault is detected. The code can be observed on the instrument panel or through an electronic diagnostic tool. An explanation of the fault codes can be found in VCADS, Guided Diagnostics or the Fault Code Manual, 8-218. Guided Diagnostics also includes symptom-based troubleshooting. To obtain Tech Tool, contact your local MACK dealer.

The Tech Tool provides complete system diagnostics. For more information, see manual 8-371 or the Tech Tool web site. Repair information is available in the respective engine service manuals and from the MACK Electronic Information System (EIS). EIS is easily accessed w i t h Te c h To o l .

Troubleshooting Technique

Talk to the vehicle operator. Learn how the engine operated before it failed. Ask about the maintenance schedule and the fuel, coolant and lubricant used. Begin by attempting to determine whether anything has happened recently that could point to the electrical system, but which is not related to the electronic control system.

Before Troubleshooting Begins

Before troubleshooting begins, observe all shop safety procedures.

Noise and Vibration

NORMAL VERSUS ABNORMAL

Noise is the name we give to vibration that irritates us through our ears. Vibration can be felt without being heard. Engine operation can cause vibration and noise throughout a vehicle that we regard as “normal.”

Abnormal noises and vibrations suggest that something is not working properly or is not assembled properly. A damaged driveshaft can cause abnormal vibration. A loose fastener allows two surfaces to rub or slap together causing unusual noise in response to the vibration.

Be sure to discuss noise and vibration issues with the driver. It is important to discover under what conditions these occur. Maybe a test drive will be necessary to familiarize yourself with the details of the driver's story. Even so, it will probably be necessary to start the diagnostic process with a guess as to the nature of the difficulty.

Depending on the vehicle configuration, a problem may be caused, or influenced, by malfunctions in other vehicle components. Be sure to inspect for unusual conditions among the batteries, tires, axles, trailer, bodybuilder adaptations and other possibilities. Consult specific service information resources according to the conditions observed. Fuel waxing, for example, can cause symptoms easily mistaken for other engine problems.

If possible, recreate the problem in an environment similar to that described by the vehicle operator. Run the engine at the temperature at which the symptom occurred.

Engine problems can be electrical, mechanical or a combination of the two. Electrical and electronic problems will, for the most part, cause fault codes to be set in the V-MAC system.

Page 50

TROUBLESHOOTING

The table below affords an opportunity to make note of various influences discovered while investigating the problem and organize thoughts. It is made for you to use as you see fit.

The noise or vibration occurs: Yes No Remarks

When the vehicle is stationary

At idle Engine Speed =

When power take-off is engaged Engine Speed =

Other items of interest

When the vehicle is in motion

With a particular superstructure

At a particular weight

At a particular speed

On a particular type of road

Driving without cruise control

Driving with cruise control

Driving using the speed governor

At full load

In a particular gear

When freewheeling (clutch disengaged)

Vehicle information

Type of chassis suspension (air?)

Type of cab suspension (air?)

Type of driver's seat (make and model)

Other items of interest

Notes:

If the solution does not become evident in the course of completing the check list above, use Tech Tool to investigate further.

Page 51

TROUBLESHOOTING

ENGINE CHECKS AND TESTS

앫 Cylinder Liner and Piston Wear, Check

앫 EGR Cooler, Pressure Test

Included in this section are the following engine checks and tests:

앫 Camshaft Sensor Depth, Check

앫 Camshaft Timing, Check

앫 Crankcase Ventilation, Check

앫 Cylinder Head, Pressure Test

앫 Engine Compression, Test

앫 Flywheel Housing Runout, Check

앫 Oil Cooler, Pressure Test

앫 Rocker Arm, Check

앫 Thermostat, Check

앫 Valve Guide Wear, Check

Special Tools

Tool No. Description Image

9989876 Dial Indicator (Available)

9990105 Sealing Plate for MP7 Cylinder Head

9990106 Sealing Plate for MP7, MP8 and MP10

9990107 Connection Disc for MP7, MP8 and MP10

9990164 Sealing Plate for MP10 Cylinder Head

Cylinder Heads

Page 52

TROUBLESHOOTING

Tool No. Description Image

9996662 Pressure Gauge and Hoses (Available)

9996956 Flywheel Turning Tool for MP7 Engine

9999683 Sweep Dial Indicator (Essential)

9999696 Magnetic Stand (Available)

(Essential)

85109036 Cylinder Head Lifting Tool (Essential)

Page 53

TROUBLESHOOTING

Tool No. Description Image

88800014 Flywheel Turning Tool for MP8 and MP10

Engines (Essential)

88800031 Camshaft Sensor Depth Gauge (Available)

88800215 Sealing Plate

88800216 EGR Cooler Test Kit

J 5347-B Dial Bore Gauge

J 42753 Fuel Line Kit

J 47364 Cylinder Head Adapter Plate

Page 54

TROUBLESHOOTING

Camshaft Sensor Depth, Check

The signal from the camshaft sensor must exceed 0.5 volt in order to start the engine. If the signal is low, check the depth setting of the sensor following this procedure.

1. Remove the plug from the flywheel housing and install the appropriate flywheel turning tool, 9996956 (MP7) or 88800014 (MP8 and MP10).

2. Check for proper camshaft position sensor clearance using the sensor depth gauge, 88800031, to determine if shims are required for sensor depth.

e. Carefully remove the gauge from the

camshaft sensor bore and observe the location of steps between the inner and outer portions of the gauge (Figure 43):

앫 Both steps below the surface of

the gauge = no shims required.

앫 One step below the surface of the

gauge = one shim required.

앫 Both steps above the surface of

the gauge = two shims required.

Figure 42 — Using Gauge at Camshaft Sensor Location

a. Rotate the engine until a tooth of the

camshaft toothed wheel is aligned with the sensor bore.

b. Insert the depth gauge into the sensor

bore until the outer part of the gauge is fully seated against the timing gear cover.

c. Loosen the thumb screw of the gauge

and push the inner part of the gauge in until it contacts a tooth of the toothed wheel.

d. Tighten the thumb screw to secure the

inner part of the gauge.

Figure 43 — Depth Gauge

3. Install the camshaft position sensor with the appropriate shim(s) and new O-ring. Secure the sensor with a bolt and plug in the harness connector.

Camshaft Timing, Check

1. Remove the cylinder head (valve) cover.

2. Check the camshaft vibration damper for damage to the pulse wheel pins.

3. Check the pulse wheel mounting for secure, square attachment.

4. Turn the engine crankshaft so that the TDC mark on the camshaft corresponds to the marks on the camshaft bearing cap No. 7 (MP7) or camshaft bearing cap No. 1 (MP8 and MP10) and the flywheel TDC mark “0” is opposite the pointer on the flywheel housing.

Page 55

TROUBLESHOOTING

5. To ensure that the camshaft is correctly installed, complete a valve lift check on the intake valves of cylinder No. 1.

앫 Temporarily adjust the No. 1 inlet rocker

arm, at the valve yoke, to zero lash.

앫 Position a dial indicator at the inlet

valve yoke for the No. 1 cylinder.

앫 Preload the dial indicator and reset the

dial to align with zero.

앫 Turn the engine in the normal direction

of engine rotation one full rotation to “0” and past to the mark 6 degrees (after TDC) on the flywheel.

앫 The dial indicator travel reading should

be approximately 1.6 ±0.03 mm (0.06 ±0.01 inch) for MP7 and MP8 or

1.4 ±0.03 mm (0.05 ±0.01 inch) for MP10. This reading indicates a correctly timed camshaft.

앫 Readjust the cylinder No. 1 inlet valves

and yoke.

If the camshaft is one tooth out of time, the dial indicator reading will be approximately 0.762 mm (0.030 inch) out of specification and should experience a fault code for the camshaft sensor.

2. Remove the CCV separator from the engine.

3. With the separator removed, rotate the turbine by hand. It should rotate easily. If it does not rotate easily, replace the separator unit.

Figure 45 — CCV Separator Turbine Wheel

4. Check the oil nozzle in the CCV base for dirt and any accumulated oily deposits. Clean the nozzle as required. If unable to clean the nozzle sufficiently, replace the complete CCV separator assembly.

6. Install the cylinder head (valve) cover.

Crankcase Ventilation, Check

1. Check the inlet pipe to the CCV separator for oil film, oil residue and particles. Remove any accumulated oil and dirt particles from the pipe.

Figure 44 — CCV Inlet Pipe Connection

Figure 46 — Oil Nozzle (Separator Base)

If the oil nozzle becomes clogged, the oil pressure is reduced and the turbine does not rotate as it should.

Page 56

TROUBLESHOOTING

Cylinder Head, Pressure Test

(Cylinder Head Removed)

The following procedure applies for MACK MP7, MP8 and MP10 engine cylinder heads. While the procedure is typical, the sealing tools required will be different for each MP engine series.

1. Clean the contact surfaces on the cylinder

head. Install the:

앫 Sealing plates, 9990105 (MP7),

9809696 and 9998266 (MP8) or 9990164 (MP10), onto the cylinder head coolant ports using cylinder head bolts and M16 nuts

앫 Connection disc, 9990107, in position

on the thermostat housing bore

앫 Plug, M12x1.5, in the temperature

sensor hole

앫 Sealing plate, 88800215, on the side of

the cylinder head

3. Lower the pressure in the cylinder head by adjusting the knob on the pressure gauge control valve.

Figure 48 — Pressure Gauge Adjustment Knob

4. Attach the cylinder head lifting tool, 85109036, to the cylinder head.

5. Using a hoist, lower the cylinder head into a container suitable for the pressure test. Fill the container with 70°C (158°F) water.

Figure 47 — Sealing Plates Installed (Typical)

1. Sealing Plates (Cooling Por ts)

2. Sealing Plate (By-Pass Por t)

3. Connection Disc (Thermostat Housing)

2. Connect the pressure gauge, 9996662, to a suitable air supply. Connect the pressure gauge hose to the connection disc on the cylinder head. Adjust the pressure to 100 kPa (14.5 psi) using the control valve. Close the stop valve for two minutes. The pressure should not fall.

Figure 49 — Testing for Air Leaks

6. With the pressure gauge connected to an air supply and the connection disc on the cylinder head, carefully open the gauge control valve.

7. Set the pressure to 50 kPa (7.25 psi) and hold the pressure for one minute.

Page 57

TROUBLESHOOTING

8. Raise the pressure to 150 kPa (21.8 psi) and close the stop valve. After two minutes, check for a drop in pressure and for any air bubbles forming around the cylinder head.

A drop in pressure and the appearance of air bubbles indicates a leak(s) in the coolant, fuel or oil passages. The source of the leak(s) must be found and the cylinder head repaired or replaced as required.

9. Lower the pressure in the cylinder head by adjusting the knob on the pressure gauge control valve.

10. Using a hoist, remove the cylinder head from the water container.

11. Remove the sealing plates and connection disc from the cylinder head. Using compressed air, blow the water off the cylinder head and out of all threaded holes.

Use care with the fuel passages to make sure that no dirt enters the fuel channels. Dirt can cause the unit injectors to be damaged.

Cylinder Liner and Piston Wear, Check

Thoroughly clean the cylinder liners and pistons before inspecting and measuring. To thoroughly check for cracks, remove the cylinder liner from the cylinder block. Mark the position of the cylinder liner in the cylinder block before removing it so it can be installed in the same position during assembly.

CYLINDER LINER

1. Check the cylinder liner for cracks, paying special attention to the liner flange. The standard dye penetrant or Magnaflux method can be used for checking.

Figure 50 — Measuring Cylinder Liner Wear

3. Measure the cylinder liner at Top Dead Center (TDC), at Bottom Dead Center (BDC) and at a couple of positions in between. At each point, measure in two directions — engine crosswise and engine lengthwise.

2. Measure the cylinder liner wear with a cylinder bore gauge. The original bore size of the cylinder liner can be used as a reference measurement.

Page 58

Figure 51 — Measurement Locations

TROUBLESHOOTING

4. If wear is greater than 0.05–0.10 mm

(0.002–0.004 inch), use a complete liner kit (cylinder liner, piston, piston rings, piston pin and cylinder liner seals). Also consider engine oil consumption to determine when to replace the cylinder liner.

Pistons and cylinder liners are available from stock only as matched pairs and should not be mixed.

PISTON

Inspect the piston ring grooves, lands, skirt and combustion bowl for wear, scuff marks, deep scratches, cracks and blow-by. Pistons are NOT repairable. Discard worn or damaged pistons.

Do NOT over-tighten the fasteners on the plugs and cap.

Figure 52 — Installation of Leak Test Kit on Cooler

Do not stamp or engrave on the TOP of the piston. Failure to heed this caution may result in severe engine damage.

To ensure that pistons are reinstalled into the same cylinders, the pistons must be tagged with the corresponding cylinder number when removed during disassembly.

EGR Cooler, Pressure Test

(Not Applicable for MP8 Euro 3 Engine)

1. Check inside the gas inlet port. If build-up of

soot is seen, perform the EGR cooler cleaning procedure before checking for leaks.

2. Lubricate the O-rings on the coolant inlet

and outlet port plugs with a suitable O-ring lubricant. Install the plugs and cap on the EGR cooler. Install the plugs on the EGR cooler coolant inlet and outlet ports. Install the coupler on the plug and connect the gauge to the coupler.

1. 88800216-1

2. 88800216-2

3. Flange Capscrew

4. Flange Nut

5. U-Bolt

6. 9996662

7. 9998333

3. Fill a container with enough water to cover the EGR cooler.

4. Lower the EGR cooler into the container of water at room temperature (or fill the cooler core with water — see NOTE).

Figure 53 — Conducting Pressure Test

Page 59

TROUBLESHOOTING

If a large enough container cannot be obtained, the EGR cooler can be tested without being immersed in water by using the test plugs included with the kit, 88800216-5, to seal the gas outlet port. The EGR cooler core can then be filled with water and tested by applying air pressure to the coolant outlet port as shown in Figure 54. When using this technique, the cooler must be tested in the upright position.

To ease the installation of the test plug, coat the inside of the hose with a suitable O-ring lubricant.

If the cooler is being tested without being immersed in water, look inside the gas inlet port. If bubbles are seen, the cooler is leaking internally and must be replaced.

A stream of bubbles seen coming from around the plugs in either of the coolant ports indicates that the O-rings may be damaged. If this is the case, remove the plugs, inspect the O-rings and replace as required.

6. Lift the EGR cooler out of the container and remove the pressure testing equipment.

7. Dump the water from inside the EGR cooler and then use compressed air to remove any remaining water from the cooler core and outer cover.

Engine Compression, Test

Figure 54 — Test with EGR Gas Outlet Port Plugged

1. Test Plug, 88800216-5 2. EGR Cooler

5. Apply air pressure (240 kPa [35 psi]) to the EGR cooler. Maintain the pressure for 15 minutes. If the EGR cooler is leaking internally, there will be a steady stream of bubbles coming from the gas inlet or outlet openings. If a steady stream of bubbles appears, replace the EGR cooler.

(on Vehicle)

Verify suspected leaks in the cylinder head or block by pressure testing before replacing these. Do not use Magnaflux replacement criteria.

Before proceeding with the tests, look for coolant stains around the sealing plugs on the cylinder head. Check that the plugs are installed properly and in good condition.

1. Remove the cylinder head (valve) cover.

On engines fitted with PowerLeash™, secure the pistons in the rocker arms with rubber bands or tie straps so the pistons do not drop out when the rocker assembly is lifted. Pistons and rockers are matched together. Failure to heed this caution may result in severe component damage.

inspections alone as

Page 60

TROUBLESHOOTING

7. Install the PowerLeash™ control valve and oil tube between the valve and the rocker arm shaft as follows:

앫 Lubricate and assemble the seals on

each end of the oil tube.

앫 Insert the larger end of the oil tube in

the rocker shaft.

앫 Make sure the oil seal is in place at the

bottom of the valve assembly.

앫 Position the valve assembly on the

mounting plate and insert the free end of the oil tube.

앫 Using a torque wrench, tighten the

attaching screws according to specification.

Figure 55 — Tie Strap Holding Engine Brake Piston

(MP7 Shown)

2. Remove the PowerLeash™ (engine brake) control valve if so equipped.

It is very important to loosen the rocker arm shaft assembly uniformly across the complete shaft. Loosening the rocker shaft assembly unevenly can cause damage.

3. Install the appropriate lifting tool, 85109050 (MP7), 85109250 (MP8) or 85109035 (MP10), on the rocker arm assembly. Loosen the rocker arm shaft uniformly across the complete shaft. Remove the rocker arm assembly.

4. Remove the unit injectors and clean the copper sleeves if necessary.

5. Install an adapter, J 47363, in each of the unit injector ports.

6. Refit the rocker arm assembly to the engine.

Figure 56 — Engine Brake Control Valve Oil Tube

1. Control Valve

2. Oil Tube

Orientation (MP7 Only)

3. Rocker Arm Shaft

8. Connect a remote starter switch to the starter.

Do not run the starter motor for longer than 15 seconds at a time. Wait 60 seconds before trying again.

Page 61

TROUBLESHOOTING

9. Connect the compression gauge, J 6692-B, to the adapter on the first cylinder. Crank the engine with the remote starter switch until the needle on the compression gauge stops moving (maximum compression). Record and repeat for all remaining cylinders.

10. Remove the screws for the PowerLeash™ control valve.

11. Remove the control valve and the oil tube between the valve and the rocker arm shaft.

12. Install the lifting tool, 85109050 (MP7), 85109250 (MP8) or 85109035 (MP10), on the rocker arm assembly. Loosen the rocker arm shaft uniformly across the complete shaft. Remove the rocker arm shaft assembly.

13. Remove the J 47363 adapters from all of the cylinders.

14. Install the unit injectors using new O-rings and new sealing washers.

15. Connect the wiring harness to the unit injectors.

20. Tighten the control valve screws according to specification and then connect the wiring harness to the valve assembly.

21. Adjust the valve and the unit injector rockers.

22. Install the cylinder head cover.

23. Bleed the fuel system.

Flywheel Housing Runout, Check

(Clutch Removed)

CHECKING AXIAL AND RADIAL RUNOUT

1. Clean the flywheel and flywheel housing.

2. Remove the plug from the flywheel housing and install the appropriate flywheel turning tool, 9996956 (MP7) or 88800014 (MP8, MP10).

16. Carefully lower the rocker arm shaft assembly onto the head.

17. Remove the lifting tool from the rocker arm shaft.

It is very important to tighten the rocker arm shaft assembly uniformly across the complete shaft. Tightening unevenly can cause damage to the rocker arm shaft assembly.

18. Tighten the rocker arm shaft screws in the sequence specified.

19. Install the PowerLeash™ control valve and oil tube between the valve and the rocker arm shaft making sure the sealing rings are correctly positioned before tightening the screws.

If the oil tube is installed incorrectly with the large end in the control valve and the small end in the rocker arm shaft, oil leaks will occur. This may cause oil starvation in the rocker arms which can result in engine failure.

Figure 57 — Turning Flywheel (MP8 Shown, Typical)

3. To check axial runout, attach the dial gauge to the flywheel using the magnetic base and position its tip against the outer flange (transmission mounting surface) of the flywheel housing. Set the dial gauge to zero.

4. Rotate the flywheel and note the indicated runout at a minimum of four locations around the outer flange of the housing. Compare the noted runout with the specified axial runout tolerance.

Page 62

TROUBLESHOOTING

Figure 58 — Checking Axial Runout

1. Magnetic Stand, 9999696

2. Sweep Dial Indicator, 9999683

Figure 59 — Checking Radial Runout

1. Dial Gauge, 9989876 2. Magnetic Stand, 9999696

5. To check radial runout, position the tip of the dial gauge against the inner flange of the flywheel housing. Rotate the flywheel and note the indicated runout, again at a minimum of four locations around the inner flange of the housing. Compare the noted runout with the specified radial runout tolerance.

6. If the runout values are out of specification, check the mating surface for the flywheel housing against the engine block and the mating surface for the flywheel on the crankshaft. Do this before replacing the flywheel housing.

7. Remove the flywheel turning tool and reinstall the plug in the flywheel housing.

Oil Cooler, Pressure Test

1. Clean the coolant side of the oil cooler with a water-soluble degreasing fluid. Flush the oil side of the cooler with degreasing solvent.

2. Install the clamp tools, 9996845, making sure they are properly seated.

Page 63

TROUBLESHOOTING

Figure 60 — Clamp Tools, Installed

3. Adjust the pressure gauge reduction valve knob until the pressure gauge needle is at zero.

4. Connect the pressure gauge assembly to the fitting on the clamp. Lower the oil cooler into a bath of water. The water temperature should be at approximately 70°C (160°F).

Rocker Arm, Check

Make sure there is clearance between the rocker arm rollers and the camshaft when performing the following rocker arm bushing and roller bushing checks.

ROCKER ARM BUSHINGS

1. Install the appropriate flywheel turning tool, 9996956 (MP7) or 88800014 (MP8 and MP10), and turn the engine until the camshaft is in a position where the rocker arm roller being checked is on the base circle of the camshaft lobe. Make sure that there is clearance between the roller and camshaft.

To check the injector, the rocker arm roller must be on the base circle of the camshaft lobe and the injector adjusting screw backed off (preload must be readjusted).

Figure 61 — Testing Oil Cooler

5. Increase the pressure to 250 kPa (35 psi) using the reduction valve knob and check for air bubbles emerging from the oil cooler. The test period should last for at least one minute.

Air bubbles emerging from the oil cooler indicate a leak. The oil cooler should be replaced.

2. Position the magnetic stand, 9999696, and dial indicator, 9989876, so that the tip of the indicator is on top of the rocker arm above the middle of the rocker arm shaft bushing area.

Page 64

Figure 62 — Dial Indicator Positioning

TROUBLESHOOTING

3. Push down on the rocker arm so that any oil film is forced out of the upper side of the rocker arm shaft.

4. Set the dial indicator to zero.

5. Position a pry bar directly under the rocker arm in the shaft area. Pry the rocker arm up and note the reading on the dial indicator. The maximum clearance allowed between the rocker arm and shaft is 0.1 mm (0.0039 inch). If the clearance is greater, replace the rocker arm and check the shaft for wear.

3. Rotate the roller a few turns so that the oil film between the roller bushing and shaft is forced out. If the roller jams, is sticky or rough, the rocker arm should be replaced.

Figure 64 — Forcing Oil from Roller

4. Place the dial indicator, 9989876, into the magnetic stand, 9999696, and position the magnetic stand as level as possible on the rocker arm.

Figure 63 — Prying Rocker Arm Up

6. Repeat the check on all other rocker arm bushings.

ROCKER ARM ROLLER BUSHINGS

1. Using the flywheel turning tool, 9996956 (MP7) or 88800014 (MP8 and MP10), turn the engine until the camshaft is in a position where the rocker arm roller being checked is on the base circle of the camshaft lobe.

2. Make sure there is clearance between the rocker arm roller and the camshaft lobe.

To check the injector, the rocker arm roller must be on the base circle of the camshaft lobe and the injector adjusting screw backed off (preload must be readjusted).

Figure 65 — Dial Indicator Positioning

5. Adjust the tip of the dial indicator so that it is horizontal to the center of the roller. Zero the dial indicator.

Page 65

TROUBLESHOOTING

Check that the tip of the dial indicator is pre-tensioned and can move in both directions.

6. Place a screwdriver between the rocker arm and the roller. Carefully pry the roller out as far as possible and note the value on the dial indicator.

Use care when prying or pressing on the roller to avoid damage to the surface of the roller.

Figure 67 — Pressing Roller In

Figure 66 — Prying Roller Out

7. Using a blunt object, press the roller in as far as possible. Note the reading on the dial indicator. The maximum clearance allowed between the roller bushing and shaft is

0.1 mm (0.0039 inch). If the clearance is greater than this, replace the rocker arm.

8. When replacing a rocker arm, lubricate the new rocker arm roller bushing with clean engine oil. Use an oil can and insert the nozzle into the oil channel passage. Rotate the roller while lubricating and check that oil comes out on both sides of the roller.

Page 66

Figure 68 — Lubricating Rocker

9. Repeat the check on all other rocker arm roller bushings as necessary.

TROUBLESHOOTING

Thermostat, Check

With the thermostat removed from the engine, check its operation as follows:

1. Check to be sure that the thermostat closes fully. This can be done by holding it up to the light to verify that there is no visible gap at the opening point. If the thermostat does not close properly, replace it.

2. Add water to a suitable container and warm the water to 75°C (167°F). With the water warmed, immerse the thermostat in the water. Use a piece of wire attached to the thermostat.

3. After at least 30 seconds, check that the thermostat is still closed.

4. Now warm the water to 100°C (212°F). After at least 30 seconds at the boiling point, check that the thermostat has opened approximately 16 mm (0.63 inch). If the thermostat has not opened, it must be replaced. A good thermostat starts to close at approximately 92°C (198°F) and is fully closed at approximately 82°C (180°F).

Figure 69 — Thermostat Closed

Figure 70 — Thermostat Open

Page 67

TROUBLESHOOTING

Valve Guide Wear, Check

WEAR CHECK

1. Remove the oil seals from the valve guides.

2. Mount the cylinder head on a suitable engine stand using the cylinder head adapter plate J 47364.

3. Install a new valve into the guide so that the end of the valve stem is even with the valve guide edge.

4. Using the dial indicator 9989876 and holder 9999696, place the tip of the dial indicator against the edge of the valve disc. Move the valve back and forth laterally in the direction of the intake/exhaust ports. Note the measured value and compare it with the acceptable wear limit specified for the engine.

Figure 71 — Measuring Valve Guide Wear

1. Dial Indicator, 9989876 2. Magnetic Stand, 9999696

5. Repeat Step 4 to check all valve guides.

Replace the valve guides if the measured values exceed the acceptable wear limit.

Page 68

MAINTENANCE

Page 69

MAINTENANCE

LUBRICATION SYSTEM MAINTENANCE

Special Tool

Tool No. Description Image

9998487 Oil Filter Wrench (Available)

Oil Level Check

When checking oil levels, the vehicle must be parked on level ground. Components must be filled to the correct level. DO NOT OVERFILL.

The best time to check oil level is while the engine is COLD (prior to starting at the beginning of the work day, or after the vehicle has sat approximately 2 hours). At normal operating temperature (engine oil temperature above 80°C [175°F]), oil level can be checked 15 minutes after shut down.

Failure to wait a sufficient amount of time (2 hours if engine oil temperature is below 80°C [175°F]) or 15 minutes if oil temperature is above 80°C [175°F]) will result in an inaccurate dipstick reading.

For accurate oil level readings, the dipstick must be inserted fully into the dipstick tube. The level must be close to the FULL line (at least between the LOW and FULL lines) on the dipstick, but must NOT exceed the FULL line.

Figure 72 — Oil Level Check

Page 70

MAINTENANCE

Oil and Filter Change Procedure

[219 EV]

This engine is equipped with improved spin-on type oil filters.

DISPOSABLE SPIN-ON OIL FILTER REPLACEMENT

Change oil and replace oil filters using the following procedure:

1. Run the engine until normal operating temperature is reached. Then, shut off the engine and drain the oil before the engine cools.

2. Thoroughly clean the area around the filters before removing.

3. Using filter wrench 9998487 or equivalent, remove the spin-on filters and wipe the filter mounting base clean.

4. Fill each filter with 1.9 liters (2 quarts) of the specified engine oil. DO NOT allow any contaminants to enter the filters while filling.

Crankcase Ventilation System

The crankcase ventilation (CCV) system separator is not repairable. If there is apparently faulty operation, perform these inspections before replacing the separator.

1. Inspect the separator inlet hose and connectors at the valve cover and at the separator. Remove any obstruction, oil film, residue and particles.

2. Inspect the separator outlet hose and connector. Remove any obstruction, oil film, residue and particles.

3. Remove the separator and attempt to turn the turbine manually. If it does not turn easily, replace the separator.

4. If the turbine turns easily, inspect and clean the oil jet nozzle.

5. Reassemble the separator and the hoses.

6. If faulty operation continues, continue fault tracing with Guided Diagnostics.

5. Apply a film of clean engine oil to the sealing gasket on each new filter.

6. Install the filters and tighten 3/4 to 1 turn after the gasket contacts the base.

7. Fill the crankcase with the recommended engine oil. If the engine is equipped with a REPTO unit, add one additional quart.

8. Start the engine and check for leaks. Run the engine for approximately five minutes, then shut it off and recheck the oil level. Add oil if necessary.

Use of anything other than genuine MACK filters may cause damage and void the engine warranty. Change filters according to the recommended maintenance schedule.

Page 71

MAINTENANCE

FUEL FILTER REPLACEMENT

Fuel Filter Change

[231 BA]

FILTER DESCRIPTION

Two filters ensure that clean, waterless fuel reaches the electronic unit injectors. One is a full-flow filter, the other is a water separating pre-filter with a transparent cup to collect and drain the water. A water-in-fuel sensor informs the driver of excessive accumulation in the cup. The water separating pre-filter is in the “suction side” of the fuel circuit. It is a spin-on type with one end of its casing threaded to receive the cup.

The full-flow main filter is on the “pressure side” of the circuit. It is also an easily replaced spin-on filter. The casing completely encloses the filter element. This filter is rated at 3–5 microns.

FUEL FILTER REPLACEMENT

Because of ice buildup or fuel waxing which can clog fuel filters, it may be necessary during extremely cold weather to reduce the time or mileage interval between fuel filter changes.

Be careful to prevent foreign matter of any kind from entering the filters during service.

Install new fuel filters dry.

Water Separating Pre-Filter Replacement

To replace the water separating pre-filter:

1. Disconnect the electrical cable.

2. Make sure the filter casing is thoroughly cleaned. If not already done, wash the area around the filter mounting adapter with a suitable solvent and blow dry with compressed air.

Figure 73 — Fuel Filters

1. Water Separating Pre-Filter

2. Water Separator Bowl

3. Water-in-Fuel Sensor Harness

3. With a suitable container in place to collect spillage, open the fitting and drain the filter.

4. Unscrew and remove the water cup.

5. Using a filter wrench, remove the filter from the mounting bracket and discard it safely.

6. Apply a thin film of clean engine oil to the sealing gasket of the new filter.

7. Screw the new dry filter in place and tighten an additional 3/4 to 1 turn by hand after the gasket contacts the base.

After filter installation, operate the hand primer to fill the fuel filters before attempting to start the engine.

8. Screw the water cup into the filter casing.

4. Drain Assembly

5. Full-Flow Main Filter

Page 72

MAINTENANCE

Full-Flow Main Filter Replacement

There is a new-style pre-filter with a stepped-down diameter at the bottom of the filter. The earlier-style filter has straight sides with a larger bottom diameter which requires an adapter to attach the fuel/water separator bowl to the filter. When replacing the previous straight-sided filter with the current stepped-down version, the adapter is not used. However, do not discard the adapter as it can be used should inventory of the earlier-style filter still be available.

9. If necessary, replace the full-flow main filter. See the following instructions.

10. Connect the electrical cable.

11. Start the engine and run at idle for five minutes to fill the filter with fuel.

12. Check for leaks.

To replace the full-flow main filter:

1. Make sure the filter casing is thoroughly cleaned. If not already done, wash the area around the filter mounting adapter with a suitable solvent and blow dry with compressed air.

2. Put a suitable container in place to collect spillage.

3. Using a filter wrench, remove the filter casing from the mounting bracket and discard it.

4. Apply a thin film of clean engine oil to the sealing gasket of the new filter.

5. Screw the new dry filter in place and tighten an additional 3/4 to 1 turn by hand after the gasket contacts the base.

6. If necessary, replace the water separating pre-filter. See the preceding instructions.

7. Start the engine and run at idle for five minutes to fill the filter with fuel.

8. Check for leaks.

Severe engine damage may be caused by attempting to prime the fuel system using an auxiliary pump or by applying air pressure in the fuel tank. These techniques may destroy seals that prevent fuel from leaking into the crankcase.

Page 73

MAINTENANCE

COOLING SYSTEM MAINTENANCE

Special Tool

Tool No. Description Image

J 48061 Coolant Filter Wrench (Available)

Coolant Drain Outlets

Extra outlets provide convenient drain sites for use during maintenance and other procedures involving coolant.

Coolant Filter

The coolant filter attaches to the back of the coolant pump housing. It resembles a spin-on oil filter. The filter element and casing are replaced as a unit.

For Australia, engines are not equipped with the coolant filter. VCS coolant is used to protect the cooling system.

REMOVE AND REPLACE

1. Close the shut-off valve on the coolant pump housing.

In the closed position, the pin on the shut-off valve should be horizontal.

2. Place a suitable container below the filter to collect spilled coolant.

3. Using filter wrench J 48061 or equivalent, unscrew the filter and discard it safely.

4. Apply a light film of coolant on the face of the new filter gasket.

5. Screw the new filter on the threaded nipple extending from the mounting flange.

Figure 74 — Coolant Filter

1. Shut-Off Valve 2. Coolant Filter

Page 74

6. Using the filter wrench, tighten the filter one full turn after the gasket contacts the base.

7. Open the shut-off valve on the coolant pump housing.

8. Check for any coolant leaks.

MAINTENANCE

DRIVE BELT REPLACEMENT AND TENSIONING

[216 AA]

General Information

The service life of the multi-groove belts is considerably improved over other systems and allows the use of higher horsepower cooling fans. All MP8 engines are equipped with multi-groove belt systems.

MP8 Engine

In the dual multi-groove drive belt arrangement, the fan drive and coolant pump are driven directly from the crankshaft pulley by a 10- or 12-rib multi-groove belt. The alternator and the air conditioning compressor (if equipped) are driven off the crankshaft pulley by a six-rib multi-groove belt (Figure 75). Two automatic tensioners are used, one for the fan drive and one for the accessory drive.

The lower tensioner for the fan and coolant pump is mounted on the coolant pump housing. This tensioner applies its load counterclockwise. The upper tensioner for the alternator (and refrigerant compressor if so equipped) is mounted on the alternator bracket. The tensioner applies its load in a counterclockwise direction.

Automatically Tensioned System

INSTALLATION

Swing the tensioner to the fully sprung position and without force, using belt tensioner tool, J 44392, place the belt over the pulleys. Do not allow the tensioner to snap against its stops. Do not pry the belt over a pulley.

TENSIONING

No tensioning adjustment is required. Once the tensioner is released against the belt, the belt is tightened to optimum tension automatically at all speeds and loads.

Figure 75 — Belt-Drive Arrangement

1. Conventional 2. LCF (N/A Australia)

MAINTENANCE

The condition of the belt and tensioner should be checked when performing preventive maintenance inspections. Belt tension levels need not be checked as long as the tensioner is in good condition and there is no evidence of a loose belt.

Page 75

NOTES

Page 76

REPAIR INSTRUCTIONS, PART 1

Page 77

REPAIR INSTRUCTIONS, PART 1

ENGINE REMOVAL

Special Tools

Tool No. Description Image

9998487 Oil Filter Wrench (Available)

DBT2V700 Coolant Extractor/Injector

J 47038-3 J 47038-4 J 47038-6 J 47038-8

J 48061 Coolant Conditioner Filter Wrench (Not

Engine Lifting Tool Set

required for vehicles manufactured in Australia)

Page 78

REPAIR INSTRUCTIONS, PART 1

General Instructions

Before removing the engine, make sure tools and equipment are inspected for safety and available for use.

앫 It is good practice to steam clean the engine

to remove road grime, grease and oil before starting work. Steam cleaning the engine and engine area allows more detailed inspection and improved workmanship.

앫 Prevent moisture from entering the air intake

system. If moisture enters the system, make sure it is removed (dried) before the engine is reinstalled.

앫 Prevent the steam cleaning nozzle from

spraying directly on any electronic components and connections.

앫 Avoid the use of any caustic or corrosive

cleaning detergents.

3. Using the oil filter wrench, 9998487 or

equivalent, remove the oil filters.

4. Using a suitable filter wrench, remove the

fuel filters.

5. Using the coolant filter wrench, J 48061 or

equivalent, remove the coolant filter.

6. Disconnect the inlet air heater if present.

7. If the vehicle is equipped with air

conditioning:

a. Using A/C refrigerant recovery and

recycling equipment, recover the refrigerant.

b. Disconnect the A/C compressor

discharge hose at the connection near the radiator support.

c. Disconnect the A/C line at the

receiver/dryer.

d. Locate and disengage the electrical

connector from the binary pressure switch on the receiver/dryer.

e. Locate and disengage the electrical

connector from the low-pressure cutout switch in the A/C refrigerant line.

1. Position the vehicle on a flat, level surface with ample work space around the vehicle.

2. Apply the parking brake and block the wheels to prevent the vehicle from moving. Observe all safety precautions.

3. Disconnect the battery negative (ground) cable.

4. Drain the air tanks.

Removal

1. Remove the hood. On cab over engine models, tilt the cab (N/A Australia).

2. Place suitable containers beneath the engine and drain the oil and coolant. Open the coolant drain valves in the cylinder block, the EGR cooler and the radiator.

If available, use the coolant extractor, DBT2V700, to remove coolant from the engine.

8. Disconnect and remove the upper radiator tube from the engine.

9. Disconnect the cab heater and fuel heater coolant return lines from the radiator lower tube (if applicable).

10. Disconnect and remove the lower radiator tube.

11. Remove the charge air cooler inlet tube and hoses.

12. Remove the charge air cooler outlet tube and hoses.

13. Disconnect the radiator fan if electronically controlled.

The radiator and charge air cooler assembly is heavy and difficult to handle. Provide a suitable lifting device and a helper to support it safely during removal.

14. Remove the radiator and charge air cooler assembly.

Page 79

REPAIR INSTRUCTIONS, PART 1

The fan assembly is heavy and difficult to handle. Obtain assistance to support it safely during removal.

16. If equipped, remove the exhaust bracket from the flywheel housing.

Use a container to collect power steering fluid.

15. Remove the fan assembly.

If equipped with an electronically-controlled viscous fan, store the fan assembly face down (hub flange up) or vertically as shown to prevent fluid leaking from the assembly.

17. Remove the power steering hoses.

18. Disconnect the exhaust system from the turbocharger.

19. Disconnect electrical cables or wires connected to the starter.

20. Disconnect or remove all other items attached to the frame or cab that would prevent engine removal, such as:

a. Clutch linkage

b. Ground straps

c. Electrical wiring

d. Coolant tubing

e. Air lines

f. Fuel lines

g. Hydraulic hoses or tubing

21. Remove the valve cover.

Figure 76 — Viscous Fan Drive Assembly Storage

1. OK to Store with Fan Blade in Vertical Position.

2. OK to Store with Fan Blade in Horizontal Position and Mounting Flange Up. Do Not with Mounting Flange Down.

Cover the valve mechanism and gear train with a suitable c\loth or similar covering to prevent dirt and debris from entering the engine.

Use a transmission jack to support the transmission when disconnected from the engine.

Store

Page 80

REPAIR INSTRUCTIONS, PART 1

22. With transmission jack in place, remove the screws attaching the transmission to the engine.

a. If a manual transmission, make certain

the clutch linkage and brackets have been removed.

b. If an automatic transmission, make

certain the torque converter access panel and the torque converter have been removed.

Obtain a helper and use a lifting device, such as engine lifting tool, J 47038, to support the engine safely during removal.

23. Attach the engine lifting tool, J 47038, to the engine. Secure the engine lifting tool to the front of the cylinder head and to the rear at the flywheel housing.

Ensure all bolts and pins in the lifting tool are correctly positioned prior to removing the engine from the chassis. Failure to properly install all bolts and pins of the engine lifting tool can result in personal injury or death.

24. Remove the screws that secure the rear engine support brackets to the frame brackets.

25. Remove the bolts that secure the front engine support to the frame crossmember.

While removing the engine, watch for obstructions that may interfere, such as engine and chassis components, brackets, clamps and other parts still attached to the engine. Failure to heed this caution may result in severe damage to the engine and other components.

26. Using the lifting device and the aid of the helper, remove the engine from the vehicle.

Before attempting to remove the cylinder head from the cylinder block, ensure that the screws holding the head against the timing gear mounting plate have been removed. Failure to heed this caution may result in severe damage to the engine and other components.

Page 81

REPAIR INSTRUCTIONS, PART 1

ENGINE DISASSEMBLY MACK MP8 Euro 4 Engine [200 EA]

Special Tools

Tool No. Description Image

9990006 Two-Jaw Puller for Unit Injector Removal,

use with 9990013 (Essential)

9990013 Slide Hammer

9990114 Main Bearing Cap Puller

9990262 Slide Hammer Adapter

9991821 Slide Hammer for Pilot Bearing Removal

and other various uses (Available)

Page 82

REPAIR INSTRUCTIONS, PART 1

Tool No. Description Image

9996400 Slide Hammer

9996966 Liner Hold-Down Tools (Essential)

9998249 Unit Injector Protection Sleeves (Essential)

9998251 Unit Injector Bore Sealing Plug (Essential)

9998267 Dowels (Locating Tools for the Timing Gear

9998511 Lever

Mounting Plate)

Page 83

REPAIR INSTRUCTIONS, PART 1

Tool No. Description Image

85109034 Camshaft Lifting Bar (Essential)

85109250 Rocker Shaft Assembly Lifting Tool

85109980 Camshaft Bearing Cap Removal Tool, use

88800014 Flywheel Turning Tool (Essential)

88800021 Front Main Seal Remover/Installer

(Essential)

with slide hammer, 9990013

(Essential)

88800188 Cylinder Head Lifting Tool (Essential)

Page 84

REPAIR INSTRUCTIONS, PART 1

Tool No. Description Image

J 41989-A Valve Spring Compressor

J 48662 Engine Stand Adapter Plate (Available)

J 48922 Heavy-Duty Unit Injector Puller

J 49002 Crankshaft Lifting Tool (Essential)

Page 85

REPAIR INSTRUCTIONS, PART 1

General Instructions

[210 EN]

This section includes step-by-step procedures for disassembly of the engine. After cleaning components, store them where they will remain clean until needed for reassembly.

The sequence in which components are removed from the engine may vary depending on the type of engine repair stand used. The repair stand identified for this procedure uses a mounting plate attached to the left side of the engine which requires the removal of certain left side components to provide space for attachment of the mounting plate. This must be done prior to mounting the engine on the repair stand.

Failure to follow the sequence of operations may result in damage to components or personal injury.

Mounting the Engine on a Repair Stand

[200 EB]

If the engine is to be mounted on a repair stand by means of a mounting plate attached to its left side, the mounting surfaces must be clear of obstruction.

Figure 77 — Components to be Removed Before

Mounting on a Repair Stand — Conventional Chassis,

Typ ical

1. Wiring Harness Block

2. CCV Tubing

3. EECU Cooling Plate

4. EECU

5. Fuel Filter Housing Assembly

6. CCV Separator Assembly

In order to attach the mounting plate, J 48662, to the left side of the engine, the following components must also be removed if present.

1. Remove the dipstick and oil fill pipe.

2. Remove the crankcase ventilation (CCV) separator and tubing.

3. Tag the electrical connectors on the left side of the engine to facilitate reconnection upon reassembly.

4. Unlock and remove the harness end connectors attached to the EECU. Remove the screws from the harness retainer clamps. Then, push the connector locks inward and rotate outward to disconnect both wiring harnesses from the EECU.

Page 86

REPAIR INSTRUCTIONS, PART 1

Figure 78 — EECU Harness Connectors

Use care to avoid damaging the terminal pins.

5. Unlock and separate the external wiring harness connectors at the various junctions and sensors.

11. Attach the engine mounting plate, J 48662, to the left side of the engine.

12. Using a suitable hoist and the appropriate lifting device, attach the engine to the repair stand.

EGR Crossover Piping Removal

[214 HN, HP, HR]

1. Loosen and remove the V-clamps at each end of the crossover pipe.

6. Remove the clamps holding the harness to the cylinder block.

7. Remove the fasteners securing the wiring harness block to the cylinder block. Position the harness block and leads out-of-way.

Use suitable rags and containers for collecting fuel and coolant drainage at each of the following steps.

8. Loosen the fuel line banjo fittings. Remove the banjo fittings, clamps and the following fuel lines from the side of the engine.

앫 Fuel return line — EECU cooling

plate-to-filter valve housing

앫 Fuel return line — cylinder head (at

front)-to-filter valve housing

앫 Fuel supply line — filter valve

housing-to-cylinder head (at rear)

앫 Fuel supply and return lines — fuel

pump-to-filter valve housing

Figure 79 — EGR Crossover Pipe

1. Venturi Outlet Pipe

2. Crossover Pipe

3. Mixer Inlet Pipe (Elbow)

2. Remove the crossover pipe from the engine. Discard the O-ring seals.

3. Remove the fasteners attaching the mixer inlet pipe to the mixer and remove the pipe. Discard the O-ring.

9. Remove the filter housing assembly.

10. Remove the cooling plate and the EECU from the cylinder block.

Figure 80 — Mixer Inlet Pipe (Elbow)

Page 87

REPAIR INSTRUCTIONS, PART 1

4. Disconnect the EGR temperature sensor lead at the wiring harness connector.

5. Loosen the collar nut and remove the EGR temperature sensor from the venturi tube outlet pipe.

Figure 81 — EGR Temperature Sensor

6. Loosen and remove the V-clamp connecting the outlet pipe at the top end of the venturi tube.

7. Remove the fasteners and retainer strap securing the venturi outlet pipe to the mounting bracket and remove the pipe from the engine.

EGR Venturi Tube Removal

1. Disconnect the wiring harness at the EGR pressure differential sensor mounted on the venturi tube. Remove the fasteners and remove the sensor from the engine.

Figure 83 — EGR Pressure Differential Sensor

2. Loosen the clamp on the coupling hose at the venturi tube inlet elbow.

Page 88

Figure 84 — Venturi Inlet Elbow and Coupling Hose

3. Remove the mounting fasteners and remove the venturi tube assembly (with pressure differential sensor) from the engine.

Figure 82 — Venturi Outlet Pipe

REPAIR INSTRUCTIONS, PART 1

Figure 85 — EGR Venturi Tube

Cylinder Head (Valve) Cover Removal

[211 JB]

1. Remove the fasteners and remove the crankcase ventilation pipe.

Figure 87 — Cylinder Head Cover

3. Remove the cover from the cylinder head.

Figure 86 — Crankcase Ventilation Pipe

2. Remove the spring-loaded screws attaching the cylinder head (valve) cover to the cylinder head.

Engine Wiring Harness Removal

[723 KA]

1. To facilitate connection at reassembly, tag all harness connectors to the various engine sensors and components prior to disconnecting them. Also, note the routing of the harness and leads for proper installation at reassembly.

2. If not already done, unlock and remove the harness end connectors attached to the EECU.

3. Unlock and separate the connectors at the various sensors, engine components and harness junctions.

4. Remove the clamps holding the harness to the cylinder head and block.

5. At the top of the cylinder head, disconnect the wiring harness at each unit injector.

Page 89

MACK Mp8 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual