Operation and maintenance manual

Flow Diagram, Fuel System QSB4.5 and QSB6.7

Page D-2 Section D - System Diagrams

Flow Diagram, Fuel System

Flow Diagram

1 From fuel supply tank

2 Water/fuel separator (not mounted on engine)

3 ECM cooling plate *

4 To fuel gear pump

5 To fuel filter

6 Fuel filter head

7 Fuel filter

8 To high-pressure pump

9 High-pressure pump

10 To fuel rail

11 Fuel rail

12 To injectors

13 High-pressure connector

14 Injector

15 Fuel return from injectors and fuel rail to fuel filter head

16 Fuel return from high-pressure pump to fuel filter head

17 Fuel return manifold

18 To fuel supply tank.

NOTE: * Engines are either equipped with an air cooled or fuel cooled ECM. If an air cooled ECM is used, the fuel

enters the engine from the OEM connection at the gear pump inlet.

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