Inspection of the EPA10 and Newer Exhaust System

rv mm 49.01.000

Important: The Environmental Protection Agency's 2010 regulations mandate lowered exhaust emissions, thus requiring exhaust system components that reduce emissions. In particular the aftertreatment device (ATD), which is part of the aftertreatment system (ATS), requires special attention during regularly scheduled maintenance inspections. See Fig. for Cummins ATD sensor locations. If any discrepancies are discovered, refer to the engine manufacturer's service literature for repair instructions.

  1. Exhaust Outlet

  2. SCR Outlet NOx Sensor

  3. DPF Outlet Pressure Sensor

  4. DPF Intake Pressure Sensor

  5. DPF Inlet Temperature Sensor

  6. SCR Inlet Temperature Sensor

  7. SCR Outlet Temperature Sensor

Fig. 1, Cummins ATD Sensor Locations

  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.
  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. 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.
  8. Check the SCR catalyst for dents and other damage.
  9. Check for heat discoloration on the surface of the ATD. Heat discoloration may indicate internal damage; especially around the DPF.

    10. Note: Diesel exhaust fluid creeps, causing white crystals to form around the line fittings. The presence of crystals does not mean the system has a leak. Replacing fittings or troubleshooting components is not necessary unless there is a system failure or a fault code.

  10. Check the DEF tank, pump, metering unit, and lines for leaks. See of the Recreational Vehicle Chassis Workshop Manual for repair procedures.
  11. 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: EPA10 and Newer Exhaust System
Document Number: 0000120914
Manual Publication Date: 2024-05-23
Topic Publication Date: 2024-11-13