1. Remove the lower valve cover. Refer to Valve Rocker Arm Cover Replacement - Lower Left Side in Engine Mechanical - 6.6L.
2. Remove the fuel return pipe bolts.
3. Remove the fuel injector return pipe.
4. Remove and discard the return pipe gaskets.

Important: Always install NEW copper gaskets onto the fuel injector fuel return pipe.

1. Install the NEW gaskets onto fuel injector return pipe.
2. Install the fuel injector return pipe.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

3. Install the fuel injector return pipe bolts.

Tighten
Tighten the bolts to 16 N·m (12 lb ft).

4. Install the lower valve cover. Refer to Valve Rocker Arm Cover Replacement - Lower Left Side in Engine Mechanical - 6.6L.