THE_ALASKAN
Diesel Freak
When I rebuilt my 7.3 (2 times 
) I had a chance to pull and replace the injector cups. Your remove them by threading a large tap into the cup and attach a slide hammer to it and yank them out. They are held in with some loc-tite and installed with a good swift hit of a hammer and injector cup installation tool. The injector cup is the only thing keeping the anti-freeze out of your injectors and valve covers. If the cup is cracked between the fuel O-Rings, the higher fuel press will cause the fuel to bleed into the anti-freeze. I have a friend who owns a diesel repair shop and he replaces about 1-2 cups a week. One time when I pulled an injector out, a small amount of antifreeze was in the bottom of the cup because the cup had a small crack it. It happens and not that big of a deal to replace, but number 7 & 8 are a PITA to get the slide hammer into. Anyway, there's my limited knowledge of the injector cups.
JIM
) I had a chance to pull and replace the injector cups. Your remove them by threading a large tap into the cup and attach a slide hammer to it and yank them out. They are held in with some loc-tite and installed with a good swift hit of a hammer and injector cup installation tool. The injector cup is the only thing keeping the anti-freeze out of your injectors and valve covers. If the cup is cracked between the fuel O-Rings, the higher fuel press will cause the fuel to bleed into the anti-freeze. I have a friend who owns a diesel repair shop and he replaces about 1-2 cups a week. One time when I pulled an injector out, a small amount of antifreeze was in the bottom of the cup because the cup had a small crack it. It happens and not that big of a deal to replace, but number 7 & 8 are a PITA to get the slide hammer into. Anyway, there's my limited knowledge of the injector cups.JIM