RING-BACKUP 1U3307 - Caterpillar

Engine: C7 (S/N: C7S1-UP) C9 (S/N: MFF1-UP; C9S1-UP) C13 (S/N: LEE1-UP) C15 (S/N: SDP1-UP; B5R1-UP)Introduction
The following procedure identifies the proper steps in identifying and recording a serial number of a DPF. There is also an inspection process that should be followed in order to help determine if an open Service Letter for the DPF applies to that particular unit.
Hot engine components can cause injury from burns. Before performing maintenance on the engine, allow the engine and the components to cool.
Wear goggles, gloves, protective clothing, and a National Institute for Occupational Safety and Health (NIOSH) approved P95 or N95 half-face respirator when handling a used Diesel Particulate Filter or Catalytic Converter Muffler. Failure to do so could result in personal injury.
Inspection Process that is Used in order to Obtain the Serial Number of the DPF
The serial number of the DPF contains 14 characters and the serial number is engraved onto the center section of the DPF.
Illustration 1 g01675205
Breakdown of the serial number of a DPF (1) Filter size number (256, 325, 519, 556, 653, 740, or 456) (2) Filter size letter (A or C) (3) Julian date (five numbers, first two will be 06, 07 or 08) (4) Assembly identification code (A or B) (5) Filter can number (four numbers)Note: Some older diesel particulate filters do not have the same sequence of characters and the filters may only contain 13 total characters. If 13 total characters are present the character for the size of the filter (fourth character from left) is missing.
The serial number of the DPF is located at the six o'clock position (pointing toward the ground on horizontally mounted diesel particulate filters) when the DPF is installed on the chassis of a vehicle. In the six o'clock position, the serial number of the DPF can be read. The following images show examples of an engraved serial number on the center section of the DPF.
Illustration 2 g01673033
(6) Location of the serial number on the center section of the DPF