Inspection of the EPA07 Exhaust System

rv mm 49.01.000

Important: The Environmental Protection Agency's 2007 regulations require lower exhaust emissions, thus requiring new exhaust system components. See Fig.. In particular the aftertreatment device (ATD), which is part of the aftertreatment system (ATS), requires special attention during regularly scheduled maintenance inspections. If any discrepancies are discovered, refer to the engine manufacturer's service literature for repair instructions.

  1. Check for leakage at the clamp that attaches the exhaust pipe to the turbocharger exhaust outlet. If leakage exists, tighten the nut on the clamp to the required torque. If leakage persists, install a new clamp.
  2. Check the exhaust pipe, bellows, and each exhaust seal clamp for leakage, wear, cracks, or damage. Replace damaged components as needed. If leakage exists at a clamp, tighten the nuts to the required torque. If leakage persists, install a new exhaust seal clamp. Do not reuse seal clamps. Once a seal clamp is loosened or removed, it must be replaced.
  3. If present, check the condition of the insulation material around the exhaust pipe between the turbocharger and the ATD, as well as the exhaust wrap from the ATD to the diffuser.
  4. Check the ATD mounting bands for tightness. Tighten to 30 lbf·ft (41 N·m) if needed. Do not overtighten.
  5. Check for leaks around the clamps that attach the ATD in the ATS, and around the clamps that retain the DPF in the ATD. No leaks are allowed anywhere in the system.
  6. Check all sensors attached to the ATD for leaks or damaged wires. No leaks are allowed.
  7. Check the DPF exterior surface for dents or other damage. See Fig., Item A. A dent over 3 inches (76 mm) in diameter and 1/4-inch (6-mm) deep could cause internal damage to the DPF, causing it to malfunction.

    • Inspect this area of the canister for dents.

    • DOC Area

    • DPF Area

    1. Inlet Temperature Sensor

    2. Marmon Fitting at Inlet from Turbocharger

    3. Sensor Housing

    4. DPF V-Band Mounting Clamps

    5. Inlet Temperature Sensor

    6. Exhaust Outlet to Diffuser

    7. Outlet Temperature Sensor

    8. DPF Outlet Pressure Sensor

    9. DPF Intake Pressure Sensor

    Fig. 1, Cummins Aftertreatment Device

  8. Check for heat discoloration on the surface of the ATD. Heat discoloration may indicate internal damage; especially around the DPF.
  9. Check any wires, lines, or hoses within 4 inches (10 cm) of the exhaust system for heat damage. Repair or reroute as needed.
Note:
Parent topic: EPA07 Exhaust System
Document Number: 0000120911
Manual Publication Date: 2024-05-23
Topic Publication Date: 2024-11-13