Inspection of the Diesel Oxidation Catalyst (DOC)
NOTICE
If the Diesel Oxidation Catalyst (DOC) and/or the Diesel Particulate Filter (DPF) is replaced,
the root cause of its failure must be repaired. Refer to section “Heavy Duty Aftertreatment
Failure Guide”. Failure to make the necessary repairs may result in a premature failure of
the replacement components.
Note : Standard core return procedure requires that the defective DPF or DOC be returned in the container that
the replacement was shipped in.
1. Chips along the circumference of the DOC are acceptable (see arrow below). The DOC substrate is a
through-flow design and therefore, functionality is not affected.
2. Inspect the DOC for movement of the substrate inside the housing. This condition is known as slippage,
where the matting has released the substrate due to pressure and may cause damage to the substrate and
the temperature sensor if the parts come in contact. If the DOC substrate has slipped and is in contact with
or within ½ inch of the temperature sensor, replace the DOC.
3. Inspect the DOC for face cracking (1). If any crack is found, replace the DOC.
Removal of the 1-BOX™ Diesel Particulate Filter
Remove as follows:
NOTICE
If the Diesel Oxidation Catalyst (DOC) and/or the Diesel Particulate Filter (DPF) is replaced,
all applicable fault code diagnostics should be completed and the root cause of the failure
must be repaired. Refer to the DDC-SVC-MAN-0208 Heavy Duty Aftertreatment Failure
Guide. Failure to make the necessary repairs may result in a premature failure of the
replacement component. Standard core return procedure requires that the defective DPF
or DOC be returned in the container that the replacement was shipped in.
1. Shut off engine and apply the parking brake, chock the wheels, and perform any other applicable safety
steps.
2. Disconnect the batteries. Refer to Original Equipment Manufacturer (OEM) procedures.
3. If necessary, remove the passenger side fairing. Refer to OEM procedures.
4. Remove the Diesel Oxidation Catalyst (DOC) outlet temperature sensor (2).
5. Remove the six outboard heat shield mounting bolts (1).
6. Remove the outboard heat shield (2) from the 1-BOX™ configuration by disengaging the folded flange on
the top of the outboard heat shield.
7. Remove the four mounting bolts (2) from the inboard heat shield (1). Slide the inboard heat shield down
allowing better access to the inboard (DPF) filter, V-band and flat band clamp.
Note : Record the orientation of the bands and clamps. They will need to be installed in the same location.
8. Loosen the outboard V-band and flat band clamps on the outboard Diesel Particulate Filter (DPF).
9. Slide both the outboard flat band (1) and the V-band clamp (3) inward on the outboard DPF (2).
10. Remove the outboard DPF assembly (2) from the 1-BOX™ configuration and discard the flat band clamp
and V-band gasket (1).
11. Loosen the V-band and flat band clamps on the inboard DPF.
12. Slide both the inboard flat band (1) and the V-band clamp (3) inward on the inboard DPF (2).
13. Remove the inboard DPF (2) from the 1-BOX™ configuration and discard the flat band clamp and V-band
gasket (1).
Inspection of the Diesel Particulate Filter (DPF)
Inspect as follows:
NOTICE
If the Diesel Oxidation Catalyst (DOC) and/or the Diesel Particulate Filter (DPF) is replaced,
the root cause of the failure must be determined and repaired. Refer to section “Heavy
Duty Aftertreatment Failure Guide”. Failure to make the necessary repairs may result in a
premature failure of the replacement components.
Note : Standard core return procedure requires that the defective DPF or DOC be returned in the container that
the replacement was shipped in.
1. If fault code SPN 3246/FMI 0 is present, the DPFs will need to be replaced.
2. Inspect the DPF for edge chips.
Replace the DPF if the extent of edge chip depth exceeds the cell plugs and exceeds 6.35 mm (.25 in.) from the
outer edge toward the center (more than three cell rows).
3. Flange weld abnormalities caused by OEM can welds, may consist of deformities from the original
manufacturing process. This is a normal and acceptable characteristic and does not affect the functionality
of the DPF.
4. Inspect the DPF for face gouges (1). Replace the DPF if any surface gouges of the substrate extend past
the depth of the cell plugs or cause extensive visual damage to the cell plugs, allowing exhaust to pass.
5. Inspect the DPF for face cracking. Replace the DPF if any vertical cracks are visually apparent (1, 2) in the
DPF substrate.
6. Do not use the filter if the DPF cells are restricted on the surface of the substrate covering an area larger
than one square inch or the size of a quarter.
7. Inspect DPF outlet face (1) for evidence of soot (2) residue. Replace the DPF if soot is found.
Note : The best way to qualify a failed or damaged filter is by visual inspection of the substrate. Additional failure modes detectable by visual inspection are: burn-through, substrate fractures, cell fusion, and cell damage. Diesel
particulate filters that exhibit these conditions are unusable, not cleanable, and may fail to perform correctly in
their application. Replace the DPF if these failure modes are detected during inspection of the DPF.
8. The substrate shown below has experienced a burn-through. The face of the filter has been partially
melted, and the cell structure has been converted to molten ceramic. Filters that have experienced a burn
through are non-serviceable. Replace the DPF.
9. Inspect inlet face for plugging. Replace the DPF and address any cause of contamination if the DPF is
plugged with heavy oil residue, wet soot, or indications of coolant contamination.