The 6.2 and 6.5 commonly will leak from the injector fuel return line hoses. (Fig. 11, Item 23). There is no NSN assigned to these hoses, rather they are cut to length from hose p/n 9439046. As these hoses age and dry out, they tend to crack and break, resulting in fuel leaks on the engine and onto the exhaust manifolds.
We installed new upgraded replacement hose sourced from Badger Diesel in Kenosha, Wisconsin. (262-859-2444). Unlike the original hose, the extremely small (and easily distorted) hose clamps 4730-00-150-6118  are not required as the hose fastens securely to the fittings by itself..
Badger markets a complete kit to replace the return hoses as Badger Diesel 6265RLK. According to Badger, “This kit includes more than enough line to do the full job with 8″ of line per injector rather than the 3″ that the competition offers having only enough to barely do half the job. Thats 266% more line!” Badger further points out this hose is made in Germany, not China as is apparently their competitor’s hose.
In our opinion, this hose is a definite upgrade from the factory hose, and not having to use the extremely small and difficult-to-use hose clamps is a plus.