DSM.0167 Ver. 1.0 March 16, 2023
CLEANFUEL USA Gen III Dedicated Liquid Propane Injection (LPI) Service Manual for the General Motors (GM) 6.0L engine as installed in Freightliner Custom Chassis Corporation (FCCC) MT-45 and MT-55 walk-in van / package car applications.
Table of Contents
Introduction 2
Fuel System Warnings 3
Service Tool Kit 5
Table of Contents 6
Facts About Propane 10
LPI® Maintenance of the Liquid Propane LPI® System 14
Fuel Fill Valve 14
Annual Overfill Protection Device (OPD) Function Verification 14
Propane Fuel System Leak Inspection 14
Fuel Tank Maintenance 14
Injectors and Fuel Rails 15
Fuel Filter / Inline Filter 15
LPI® Fuel System Recommendation Maintenance Schedule 16
Liquid Propane Injection System Description and Operation 18
MT-45, MT-55 Chassis LPI® Fuel System Mechanization / Hydraulic Diagram 19
P63 Chassis - LPI® Fuel System Mechanization / Hydraulic Diagram 20
External Fuel Tank 21
Internal Fuel Tank 22
Filtration and Fuel Lines 23
Fuel Rails and Fuel Distribution 23
LPG Control Module 26
LPI® Fuel System Diagnosis by Symptom 28
First Approach to Diagnosing the LPI® Fuel System 29
Vehicle has No Power 29
Vehicle will Not Start 30
Engine Runs Poorly, Misfires, Backfires or Surges 31
Vehicle has Poor Fuel Economy 31
Cannot Fill the Propane Tank 31
Dashboard Fuel Gauge Not Working 32
Tank Making Noise, High Pitched Whistling Noise or Grinding Sound 33
LPI® Fuel Pump Diagnostics 34
Fuel Sender Diagnostics 35
Engine Fuel System (Universal for Freightliner MT-45 / MT-55 and P-63 Chassis 37
Fuel Rail Assembly Replacement (Drivers Side) 38
Fuel Rail Assembly Replacement (Passenger Side) 39
LPI® Fuel Injector Replacement 40
LPI® Fuel Injector Nozzle Replacement 41
Supply Distribution Block Replacement 42
Return Regulator Distribution Block Replacement 43
LPG Stainless Steel Fuel Line Replacement 44
Fuel Pressure and Temperature Sensor Replacement 45
Fuel Pressure Test Port Replacement 46
LPI® Internal Fuel Tank 48
LPI® Fuel Pump Removal MT-45 / MT-55 Chassis 49
LPI® Fuel Pump Installation MT-45 /MT-55 Chassis 51
LPI® Fuel Pump Removal P63 Chassis 54
LPI® Fuel Pump Installation P63 Chassis 56
LPI® External Fuel Tank MT-45 / MT-55 Chassis 59
Supply Valve Replacement 60
Return Valve Replacement 61
Service Evacuation Valve Replacement 62
Pressure Relief Valve Replacement 63
Overfill Protection Valve (Filler Valve) Replacement 64
Fixed Liquid Level Gauge (80% Bleeder) Replacement 65
Fuel Pump Wire Feed– Through Replacement 66
Fuel Gauge Replacement 67
Fuel Sender Replacement 68
LPI® External Fuel Tank P63 Chassis 70
Supply Valve Replacement 71
Return Valve Replacement 72
Service Evacuation Valve Replacement (Inside Baffle) 73
Service Evacuation Valve Replacement (Behind Baffle) 74
Pressure Relief Valve Replacement 75
Overfill Protection Valve (Filler Valve) Replacement 76
Fixed Liquid Level Gauge (80% Bleeder) Replacement 77
Fuel Pump Feed– through Replacement 78
Fuel Gauge Replacement 79
Fuel Sender Replacement 80
Check Valve Replacement (Supply Valve Side) 81
Check Valve Replacement (Filler Valve Side) 82
LPI® Fuel Filters 83
Fill Filter Replacement MT 45/55 Chassis 84
Supply Filter Replacement MT 45/55 Chassis 85
Supply / Fill Filter Replacement P63 Chassis 86
LPI® Fuel Lines (MT-45 / MT-55 Chassis) 88
FFWR Torque (Flats From Wrench Resistance) 89
Filler Valve to Fill Filter 90
Fill Filter to OPD Fill Valve (Tank Fill Valve) 91
Supply Valve to Supply Filter 92
Supply Filter to Supply Solenoid (Distribution Block) 93
Return Regulator (Distribution Block) to Return Valve 94
LPI® Fuel Handling 96
Introduction To the LPI® Service Tools 97
LPI® Service Tool Kit 98
LPI® Fuel System Pressure Test 99
Evacuate / Drain Liquid Fuel from a LPI® Tank for Service 101
LPG Fuel Line Draining 102
Evacuate / Drain Liquid Fuel from the Liquid Service Valve on the LPI® Fuel Tank
(Pressure Equalization Method) 103
Evacuate / Drain Liquid fuel from the Liquid Supply Valve on the LPI® Fuel Tank
(Fuel Pump Method) 105
Evacuate / Drain Vapor Fuel from the Vapor Valve on the LPI® Fuel Tank 107
Purging & Evacuating Propane Tanks 110
Transferring Liquid fuel From the LPI® Evacuation Tank to a LPG Vehicle Fuel Tank 112
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