2006/07/01 Caterpillar

Engine:

C7 (S/N: FML1-UP; KAL1-UP; FMM1-UP; SAP1-UP; WAX1-UP)

C7 TRUCK ENGINE (S/N: NPH1-UP)

C7 TRUCK/BUS (S/N: YPG1-UP)

C9 (S/N: MTB1-UP; SRB1-UP; 9DG1-UP; C9S1-UP)

C9 ON-HIGHWAY (S/N: ETK1-UP)

A new 293-0730 Backup Ring has been released for use in all C7 and C9 On-highway Engines. The new backup ring improves the sealing of the fuel injectors. The new backup ring must be used in conjunction with the O-rings that are listed below. Refer to Illustration 1 for the locations of the O-rings and the backup rings.

If oil is leaking past the injectors and/or if a 164-11 diagnostic code is logged, replace all of the O-rings and backup rings.

If one O-ring needs to be replaced, Caterpillar recommends replacing all O-rings and all of the backup rings on all of the injectors.

Illustration 1	g01290015
(1) 238-8091 Fuel Injector Gp (2) 293-0730 Backup Ring (3) 148-2903 O-Ring Seal (4) 149-5240 Backup Ring (5) 109-3207 O-Ring Seal