7.3L Ford Injector Sleeve Replacement

The 7.3L Power Stroke isn’t known for its mechanical flaws. In fact, the engine’s one Achilles’ heel issue is out-of-the-blue camshaft position sensor failure. But that doesn’t mean everything else is bulletproof. This month, we’re introducing you to a rare problem found on ’94½ to ’03 engines: injector sleeve failure.   |   To perform the job, Flynn’s Shop used an injector sleeve extractor (A) and installation tool (B) from Rosewood Diesel Shop. In this photo, you can also see four (of eight) new sleeves (C), four removed sleeves (D), and the thread locker (E) needed to seal them in the injector bore. Known also as an injector cup, its primary functions are to seal and protect the immediate area of the injector bore within the cylinder head and keep the fuel system separate from the cooling circuit. Sleeves protect the cylinder head when aged, distorted injector O-rings begin to allow moisture inside the injector bore. In the 7.3L, they’re made from brass, a soft alloy, which conforms to the shape of the injector bore in the cylinder head. A secondary job is to help cool the injector. While it’s not your everyday, every-engine occurence, 7.3L Power Strokes that continue to rack up miles may end up encountering injector sleeve failure. Remember, it’s been a decade since the last engine rolled off the assembly line—so even if you don’t experience failure firsthand, it’s worth considering during a rebuild. Recently, our friends at Flynn’s Shop showed us how the sleeves are replaced, and the injector experts at Rosewood Diesel Shop supplied us with the tools needed to perform this unique service procedure.