Image is for illustration purposes only. Actual part may vary.

1662903

CAT INJECTOR SLEEVE O-RING

This is a Caterpillar O-ring seal, part number 1662903. It is most commonly used as the injector sleeve O-ring in Cat 3406E and C15 diesel engines. The ring creates a tight, leak-proof seal between the injector sleeve and the cylinder head, preventing fuel and combustion gases from mixing and keeping coolant out of the fuel system. You replace it whenever the injector sleeve is removed, or if you see external fuel or coolant leaks around the injector area.