SEAL 3369992 - Caterpillar

3406 And 3408 Truck Engines With Precombustion ChambersDescription of Change: Fuel injection lines groups for the above models are changed to use 7N9843 Fuel Injection Valve Nozzle Assemblies in place of the 4N1251 Fuel Injection Valve Nozzle Assemblies. The new nozzle assembly has a spring retainer with a horse shoe shape in comparison with the split retainer used in the former nozzle assembly. The improved spring retainer will extend the service life of the nozzle. An article "New Fuel Injection Lines Groups Use A Different Fuel Injection Nozzle Assembly" on Page 12 of the March 12, 1979 Service Magazine tells about the use of the new 7N9843 Fuel Injection Valve Nozzle Assembly in 3406, 3408 and 3412 Industrial, Marine and Vehicular Engines with precombustion chambers. At the time the article was written, the new nozzle was not yet approved for use in truck engines because of emission control regulations. The 7N9843 Nozzle Assembly is now approved for use in truck engines, and a Supplement has been written to cancel the last sentence of the above article.Adaptable As: The new 7N9843 Fuel Injection Valve Nozzle Assembly is a direct replacement for the former 4N1251 Fuel Injection Valve Nozzle Assembly, which is canceled.