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

9X7317

SEAL O-RING

This is a small Viton O-ring seal used to seal the fuel injector in certain Caterpillar diesel engines, primarily the 3406E and C15 Acert models. It prevents high-pressure fuel or combustion gases from leaking past the injector, helping to maintain proper engine performance and prevent fuel dilution in the oil. Replacement is recommended whenever the injector is removed or if symptoms like hard starting, rough idle, or fuel in the oil appear. Although identified as a Caterpillar part, it crosses to several aftermarket and OEM numbers like 6I1420 and M-9X7317.