Detroit Diesel 4000 Series, Service Manual, Page: 884 / 2706

SERIES 4000 12/16V SERVICE MANUAL
To avoid personal injury when working on the fuel system,
do not smoke, use open flame, or electrical equipment.
Diesel fuel is a combustible fluid. Risk of a fire from sparks
is probable. Perform maintenance in a well ventilated work
area with access to a fire extinguisher.
1. Loosen fuel return line (4) at high-pressure fuel pump to relieve fuel pressure from
high-pressure rails. See Figure 542.
2. To remove high-pressure line between high-pressure pump and high-pressure rail, remove
pipe clamp half (2).
1. High-Pressure Line ("A" Bank) 3. Low Pressure Fuel Supply Line
2. Pipe Half Clamp 4. High Pressure Pump Fuel Return Line
Figure 542 Removing High-Pressure Line Between High-Pressure Pump
and High-Pressure Rail
3. Unscrew and remove high-pressure line (1), “B” bank, on high-pressure pump and
high-pressure rail.
All information subject to change without notice.
C -738
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